Factors Influencing Fine and Gross Motor Development among

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Graduate Studies The Vault: Electronic Theses and Dissertations

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Factors Influencing Fine and Gross Motor

Development among Children 24 Months of Age:

Results from the All Our Families Study

Dodd, Shawn X.

Dodd, S. X. (2017). Factors Influencing Fine and Gross Motor Development among Children 24

Months of Age: Results from the All Our Families Study (Unpublished master's thesis). University

of Calgary, Calgary, AB. doi:10.11575/PRISM/26147

http://hdl.handle.net/11023/3808

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UNIVERSITY OF CALGARY

Factors Influencing Fine and Gross Motor Development among Children 24 Months of Age:

Results from the All Our Families Study

by

Shawn Xavier Dodd

A THESIS

SUBMITTED TO THE FACULTY OF GRADUATE STUDIES

IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE

DEGREE OF MASTER OF SCIENCE

GRADUATE PROGRAM IN BIOLOGICAL SCIENCES

CALGARY, ALBERTA

APRIL, 2017

© Shawn Xavier Dodd 2017

ii

Abstract

Objective: The objective of this study was to identify factors influencing fine and gross motor

development of Albertan children at 24 months of age.

Methods: This is a secondary analysis of data from the All Our Families study, a prospective

pregnancy cohort. Multivariable logistic regression was performed to identify factors influencing

motor development.

Results: Early developmental delays, maternal abuse and maternal postpartum drug use were

associated with an increased odds of suboptimal gross motor development at 24 months of age.

Pregnancy complications were associated with a reduction in risk for gross motor delays. Early

developmental delays, NICU admission and maternal postpartum alcohol consumption were

associated with an increased risk for delays in fine motor development at 24 months of age.

Conclusion: Delayed motor development at 24 months of age may be mitigated through

detection and intervention of early cognitive, social and motor developmental delays.

iii

Acknowledgements

I would like to extend my sincere gratitude to my supervisors, Dr. Suzanne Tough and

Dr. Brent Hagel, for their support throughout my graduate studies. Suzanne, thank you for all the

effort you have dedicated to supervising me throughout my time with the All Our Families study.

Your patience and positive disposition has been tremendously encouraging. Brent, thank you for

your optimism and guidance. I am truly grateful for the mentorship you have both provided me

with during the past two years.

I would also like to recognize Dr. Alberto Nettel-Aguirre and Dr. Jason Cabaj for the

direction, support and expertise you both have brought to this project. I am honoured to have had

such a diverse and accomplished supervising committee.

To the All Our Families team, especially Mary Canning, Muci Wu and Nikki Stephenson,

thank you for all of your help throughout my time with the team. I appreciate your patience and

support, especially during the times I had a whirlwind of questions. Thank you for making me

feel part of the team!

A very special thank you to my family and friends who continue to support me in all my

endeavours. Your ongoing support and encouragement is appreciated beyond words.

Finally, I would like to acknowledge the participants of the All Our Families study, and

the Canadian Institutes of Health Research (CIHR) for their financial support throughout my

graduate studies.

iv

Table of Contents

Abstract ........................................................................................................................................... ii

Acknowledgements ........................................................................................................................ iii

Table of Contents ........................................................................................................................... iv

List of Tables ................................................................................................................................ vii

List of Figure and Illustrations ..................................................................................................... viii

List of Abbreviations and Nomenclature ....................................................................................... ix

CHAPTER ONE: INTRODUCTION ............................................................................................. 1

1.1 Problem Statement ................................................................................................................ 1

1.2 Background ........................................................................................................................... 2

1.2.1 Child Development ........................................................................................................ 2

1.2.2 Modern Theories of Motor Development ...................................................................... 4

1.2.3 An Overview of Motor Development ............................................................................ 9

1.2.3.1 Gross motor development ..................................................................................... 13

1.2.3.2 Fine motor development ....................................................................................... 14

1.2.4 Developmental Assessment Tools ............................................................................... 16

1.2.5 Population-wide developmental screening and the importance of at-risk profiles for

developmental delays ............................................................................................................ 21

1.3 Research Objectives ............................................................................................................ 23

1.4 Research Significance ......................................................................................................... 24

1.5 Knowledge Translation ....................................................................................................... 25

1.6 Summary of Thesis Format ................................................................................................. 26

CHAPTER TWO: REVIEW OF THE LITERATURE INVESTIGATING FACTORS

ASSOCIATED WITH GENERAL, FINE AND GROSS MOTOR DEVELOPMENT .............. 27

2.1 Methods............................................................................................................................... 27

2.1.1 Data Sources and Search Strategy ............................................................................... 27

2.1.2 Inclusion Criteria ......................................................................................................... 27

2.1.3 Exclusion Criteria ........................................................................................................ 28

2.1.4 Data Extraction and Synthesis ..................................................................................... 28

2.2 Results ................................................................................................................................. 29

2.2.1 Risk Factors for Delayed General Motor Development .............................................. 30

2.2.1.1 Sociodemographic factors ..................................................................................... 71

2.2.1.2 Maternal health factors ......................................................................................... 73

2.2.1.3 Pregnancy and birth outcome factors .................................................................... 76

2.2.1.4 Child health factors ............................................................................................... 78

v

2.2.1.5 Environmental factors ........................................................................................... 79

2.2.2 Risk Factors for Delayed Fine or Gross Motor Development ..................................... 81

2.2.2.1 Sociodemographic factors ................................................................................... 110

2.2.2.2 Maternal health factors ....................................................................................... 111

2.2.2.3 Pregnancy and birth outcome factors .................................................................. 113

2.2.2.4 Child health factors ............................................................................................. 114

2.2.2.5 Environmental factors ......................................................................................... 115

2.3 Discussion ......................................................................................................................... 116

2.2.1 Critical Appraisal of the Current Body of Knowledge .............................................. 116

CHAPTER 3: METHODS .......................................................................................................... 120

3.1 Study Design ..................................................................................................................... 120

3.2 The All Our Families Study .............................................................................................. 120

3.3 Data Collection ................................................................................................................. 122

3.4 Outcome Measures............................................................................................................ 125

3.5 Exposure Variables ........................................................................................................... 126

3.5.1 Sociodemographic Factors ......................................................................................... 126

3.5.2 Maternal Health Factors ............................................................................................. 126

3.5.3 Pregnancy and Birth Outcome Factors ...................................................................... 127

3.5.4 Child Health Factors .................................................................................................. 127

3.5.5 Environmental Factors ............................................................................................... 127

3.6 Statistical Methods ............................................................................................................ 135

3.6.1 Descriptive Statistics .................................................................................................. 135

3.6.2 Bivariate Analysis ...................................................................................................... 135

3.6.3 Multivariable Logistic Regression ............................................................................. 135

3.7 Ethics................................................................................................................................. 137

CHAPTER FOUR: FACTORS RELATED TO DELAYED FINE AND GROSS MOTOR

DEVELOPMENT AMONG ALBERTAN CHILDREN AT 24 MONTHS OF AGE ............... 138

4.1 Background ....................................................................................................................... 138

4.2 Methods............................................................................................................................. 140

4.2.1 The All Our Families Study ....................................................................................... 140

4.2.3 Assessment of Fine and Gross Motor Development.................................................. 141

4.2.4 Exposure Variables .................................................................................................... 142

4.2.5 Data Analysis ............................................................................................................. 146

4.3 Results ............................................................................................................................... 147

4.3.1 Participant Characteristics ......................................................................................... 147

4.3.2 Factors Associated with Delayed Gross Motor Development ................................... 157

vi

4.3.3 Factors Associated with Delayed Fine Motor Development ..................................... 159

4.4 Discussion: ........................................................................................................................ 160

CHAPTER FIVE: CONCLUSIONS .......................................................................................... 166

5.1 Summary of Findings ........................................................................................................ 166

5.2 Limitations ........................................................................................................................ 166

5.3 Strengths ........................................................................................................................... 168

5.4 Implications of Study Results ........................................................................................... 169

5.5 Recommendations for Future Research ............................................................................ 171

REFERENCES: .......................................................................................................................... 173

APPENDIX A: DESCRIPTIVE STATISTICS FOR THE POTENTIAL

SOCIODEMOGRAPHIC, MATERNAL HEALTH, BIRTH OUTCOME, CHILD HEALTH,

AND ENVIRONMENTAL FACTORS ..................................................................................... 207

vii

List of Tables

Table 1: Mean age for the attainment of six gross motor milestones ……………...…………... 13

Table 2: Summary of articles examining factors associated with general motor development in

children 1-66 months of age ………………….……………………………....…......... 31

Table 3: Summary of articles examining factors associated with fine and/or gross motor

development in children 1-66 months of age …………………………………...…….. 82

Table 4: Comparison of AOF participants to MES participants ……………………………… 121

Table 5: Candidate variables ………………………………………………………...………... 129

Table 6: Categorization of candidate variables ………………………………………...……... 131

Table 7: Participant characteristics……………………………………………………………. 148

Table 8: Descriptive statistics for the potential sociodemographic, maternal health, birth

outcome, child health, and environmental factors ………………………………….. 151

Table 9: Final multivariable logistic regression model of factors influencing gross motor

development at 24 months of age ..…………………………………………..……… 158

Table 10: Final multivariable logistic regression model of factors influencing fine motor

development at 24 months of age ………………………………….....……………. 160

viii

List of Figure and Illustrations

Figure 1: Overview of included and excluded articles ………………………………………... 29

Figure 2: AOF Participant Recruitment Timeline ………………………………………......... 123

Figure 3: AOF Response Rates ………………………………….…………………………..... 124

ix

List of Abbreviations and Nomenclature

Symbol Definition

AOF All Our Families Study

aOR Adjusted Odds Ratio

ASQ-3 Ages and Stages Questionnaire, Third Edition

BMI Body Mass Index

CI Confidence Interval

CPS Canadian Paediatric Society

HSQ Home Screening Questionnaire

IDEAL Study Infant Development, Environment, and Lifestyle Study

IQ Intelligence Quotient

IPV Intimate Partner Violence

MES Maternity Experiences Survey

NICU Neonatal Intensive Care Unit

OR Odds Ratio

PPD Parental Psychological Distress

SD Standard Deviation

SES Socioeconomic Status

WHO World Health Organization

1

CHAPTER ONE: INTRODUCTION

1.1 Problem Statement

Up to 15% of children1,2 between 3-17 years of age are reported as experiencing either

physical, intellectual or other developmental delays, making developmental delays the most

common childhood disability2. To identify children at risk of delay, screening tools compare a

child’s development to age-adjusted standards3. Though effective, lack of systematic use of these

screening tools has resulted in less than 30% of children with developmental delays being

identified prior to kindergarten3,4. This lag in identification hinders early, effective

interventions4.

Delayed motor development is among the earliest recognizable indicators of global

developmental complications5. Current theories suggest an interplay between sensorimotor

maturation and the acquisition of cognitive and linguistic skills6,7. New challenges and sensory

information encountered through active exploration are believed to shape a child’s social and

cognitive abilities. Moreover, the development of skills that enable a child to interact with their

environment increases the breadth of experiences available to them to refine their movement and

coordination. Given the dependence of cognitive and linguistic skills on sensorimotor

development, it is imperative to understand risk factors that predispose children to motor

development delays to ensure appropriate support and interventions are available to them5.

Discerning critical risk factors will aid both health care providers and caregivers of young

children in identifying those at increased risk of delayed motor development. Motor

developmental complications may be a marker of global developmental disabilities5;

consequently, the identification of children with increased risk of motor delays may enable

2

earlier and more effective interventions4, ultimately optimizing outcomes for children and

families.

1.2 Background

1.2.1 Child Development

The evolution from a dependant infant to an autonomous adult requires the maturation of

four domains: 1) gross and fine motor skills, 2) speech and language, 3) social, personal and

activities of daily life, and 4) performance and cognition8. The course of neurodevelopmental

and physical growth is orderly, cumulative, and directional9,10. Development is described as

orderly as its progression follows a logical sequence where the attainment of one milestone

provides the foundation for the development of another9. Cumulative development suggests that

any given stage of development includes all the previous changes including newly developed

skills. Lastly, directional development indicates that child development continually progresses

towards increasing complexity10.

Together, the orderly, cumulative, and directional process of development formed the

basis of Piaget’s theory of cognitive development10. In his theory, Piaget asserted that children

develop through the progression of four universal stages: 1) sensorimotor stage, 2) pre-

operational stage, 3) concrete operational stage and 4) formal operational stage. Piaget’s theory

posits that progression through these stages is sequential, where stages could not be skipped, but

it is possible for a child to never reach a stage of development10. Together, as a child progresses

through these stages, cognitive processes are enhanced and refined.

The sensorimotor stage of development lasts from birth until 24 months of age and

includes the child’s progression from innate reflex actions to intentional movement and

3

behaviour10,11. During this stage, there is an interplay between sensorimotor maturation and the

acquisition of cognitive and linguistic skills, whereby the development of motor skills enables a

child to increasingly interact with their environment6,7,10. The new challenges and sensory

information encountered through active exploration are believed to shape a child’s social and

cognitive abilities, such as object permanence: the understanding that an object continues to exist

even when out of sight10,11. Moreover, the development of skills enabling a child to interact with

their environment increases the breadth of experiences available to them to hone both fine and

gross motor skills. As a result of the interplay between motor and cognitive development, it has

been suggested that motor development may serve as a prerequisite for later cognitive

development involved in the preoperational stage of child development12.

From 2-7 years of age, a child progresses through the preoperational age of

development10,11. During this stage, a child begins to understand the representation of objects

through symbols, such as words. Though the use of symbols represents a marked increase in

social ability compared to the sensorimotor stage, the preschool-age children exhibit difficulty in

understanding or visualizing their environment from another’s perspective. Furthermore,

children’s cognitive abilities remain limited due to centration: the narrow focus on one aspect of

a situation while neglecting other relevant aspects10,11.

The preoperational stage leads to the concrete operational stage from 7-11 years of

age10,11. The concrete operational age reflects the beginning of logical thought, where a child can

begin to solve problems by applying rules such as conservation. Though children exhibit logic,

most children’s ability to think abstractly remains limited until 11 years of age when they enter

the formal operational stage. The formal operational stage continues into adulthood where an

individual can think hypothetically and reason deductively.

4

Piaget’s theory posits that as a child progresses through these stages, cognitive processes

are enhanced and refined10. Moreover, progression through these stages is sequential, where

stages cannot be skipped, but it is possible for a child to never reach a stage of development10.

Based on this theory, early stages of development provide the foundation for future development.

This perspective is supported by the work of Bushnell and Boudreau and their suggestion that

motor development may serve as a control parameter for later development12. In 1993, they

described that motor development is a prerequisite for the development of haptic perception and

depth perception. Moreover, in their investigation of postural control and cognitive development,

Wijnroks and Van Veldhoven found that poor postural control at 6 months was also associated

with difficulties in problem solving later in development6,13.

Given the importance of early motor development on later cognitive development6,7, it is

imperative to understand the processes underlying motor control to effectively protect and

promote optimal long-term cognitive function.

1.2.2 Modern Theories of Motor Development

Since Aristotle’s view that a child’s development is a product of their experiences, and

Plato’s view that a child is born with a developmental fate, theories of early infant development

have argued the influence of heredity and environment14. Here, the transition from the early

maturationist perspective, that saw heredity as the sole influence on motor development, to the

modern dynamic systems approach, that proposes a complex interaction between the body and

the environment11, will be described.

The maturationist approach posits that the process of motor development is governed by

heredity with little influence from the environment11. The description of infant motor

5

development through the maturational approach was first describe by Arnold Gesell, a

psychologist credited with being among the first to systematically investigate early infant

development11,15. Through his investigation, Gesell described the orderly progression of

development beginning in the fetal stage and progressing throughout the child’s early life.

Noting the distinguishable sequence of movement patterns exhibited by developing children,

Gesell created the Developmental Schedules that later became the United States’ first

developmental scales11.

Gesell’s commitment to the observation of child development led to his theory that motor

development could be explained by seven guiding principles11. Through these principles, Gesell

described the cephalocaudal and proximodistal progression of development and the asymmetric,

non-linear pattern of development. Though it has since been refined, the directionality and

pattern of development described by Gesell continues to be accepted11,15.

Influenced by the work of his predecessor’s, Gesell’s principles also maintained that

motor development is a morphogenetic process, whereby changes involved in development are

autonomous and not influenced by the surrounding environment11,15,16. As such, Gesell believed

that the sequence and rate of development was determined by the child’s genetic composition.

Though Gesell later noted that the child’s surrounding environment must be supportive and align

with the child’s skill set15, he believed that the environment had no influence on motor

development, but may be important in the development of personality11.

Shortly after Gesell began investigating child development, Myrtle McGraw also started

describing the sequence of motor development16. Considered by some as a maturationist,

McGraw believed that motor development was governed by cortical maturity rather than

genetics16,17. At birth, McGraw believed that the neonatal cerebrum lacked the maturity to illicit

6

motor control. As the infant developed, however, cortical centers matured, gaining increased

control of the lower brain and spinal cord, thereby enabling the development of motor skills11.

Through the maturation of the cerebrum, McGraw believed that the increased cortical control

prevented primary reflexes from being exhibited, a process she termed cortical inhibition. The

process of cortical inhibition, however, has since been refuted11,16,17.

McGraw’s perspective that motor development was governed by cortical maturity led to a

popular series of experiments aimed at investigating whether early motor skills could be

trained17. Of note was McGraw’s investigation of a set of twins named Jimmy and Johnny;

Johnny experienced transient hypoxia following birth, whereas Jimmy did not experience any

complications16,17. In her experiment, McGraw led Johnny through intensive training in both

universal and culturally-specific skills16. Upon comparing their long-term development, McGraw

reported that there was no significant mental or motor difference between the twins. These

results were suggested by some to support the maturationist perspective surrounding child

development17. Given that Johnny did not exhibit enhanced motor development following his

exposure to an intense training environment suggested that the surrounding environment could

not alter development. Moreover, some argue that McGraw’s experiments supported the belief

that the development of the structure, or the maturation of the infant’s cortex, led to motor

development16. Others, however, credit McGraw with developing the original foundation for the

bidirectional theory between brain structure and function17,18.

Following Gesell and McGraw, the maturationist approach to motor development lost

traction. Little work was conducted as many believed the experimental questions of that time

were sufficiently supported by the results from both psychologists16,17. Though the maturationist

7

perspective of motor development is no longer widely supported, the contribution of

developmental schedules remains a prominent tool in research19.

During the period of Gesell and McGraw, Nikolai Bernstein, a Russian psychologist, also

began writing his theories on motor development and control11,19. Though only translated into

English in 1967 and largely unrecognized until recently, Bernstein’s inquiries were directed to

understanding the control mechanisms driving motor movement19. By approaching movements

as dynamic systems, Bernstein described four fundamental problems with the maturationist

approach to motor development: 1) degrees of freedom, 2) redundancy, 3) contextual variations

and 4) change11. The degrees of freedom problem suggested that the numerous muscles and

joints in the body provide too many potential movements to each be under pre-programmed

control by the motor cortex. Rather, Bernstein hypothesized that movements were composed of

multiple subsystems. These subsystems were controlled by several central impulses throughout

the central nervous system that could be combined to produce movement, thereby reducing the

degrees of freedom11.

Bernstein’s redundancy problem highlights the innumerable possible ways of completing

similar tasks11. For example, each muscle is composed of numerous motor units, and each motor

unit is composed of a section of muscle fibres innervated by a single motor neuron. For a muscle

to exert a predetermined force on an object, there are countless possible combinations of motor

units that can be stimulated to exert the force. Furthermore, the possible combinations of

stimulated motor units increase exponentially when considering each movement involves

multiple muscles. As such, two approaches have been postulated for approaching the problem of

redundancy: 1) the central controller finds a unique solution to the motor task upon each

8

exposure; and 2) the central controller facilitates solutions that are equally acceptable, and

recycles these combinations.

Lastly, Bernstein’s contextual variations problem and his change problem describe how

movements must be adaptive to different environments and circumstances11. For example, if

each movement were a result of a specific set of stored neural commands, then a unique

command would be required for each variation in the context involved in the movement. As

such, different commands would be required for walking uphill, downhill and for each variation

involved in the surface, such as bumps and grooves. Moreover, given that the morphology of the

body changes substantially from the fetal-stage to a fully developed adult, a new set of

commands would be required for movements to be properly executed at each stage of life.

Together, these problems challenge the traditional maturational and information

processing perspectives of motor development. They argue that the cortex has a finite processing

ability that would be unable to sustain the variation and complexity of movements if each

movement is pre-programmed11.

Bernstein’s perspective of motor development was unique during this period as it

transcended the historical debate between nature versus nurture11,19. Rather, in his dynamic

systems approach, Bernstein recognized the importance that both the body and the environment

play in eliciting appropriate motor tasks. Unfortunately, Bernstein’s work was not appreciated

until the 1970’s, when the dynamical systems approach was expanded by Esther Thelen, to

describe our modern understanding of motor development11,19.

Similar to Gesell’s view of motor development, the dynamic systems approach to motor

development has foundational principles. These principles require that organisms be composed

of multiple self-organizing subsystems11. These subsystems, such as the musculoskeletal or

9

nervous systems, operate together to generate the most efficient movement for a given task21.

Under this principle, the emergence of new behaviours is the result of multiple subsystems

individually maturing. As proposed by Gesell, this maturation process is non-linear, where each

subsystem experiences periods of stability and instability, which may or may not coincide with

the maturity of other subsystems11. Moreover, dynamic systems theory proposes that changes in

one subsystem will impact other subsystems, and subsequently the system in its entirety21,22. As

such, new motor skills are exhibited during periods where the underlying subsystems have each

developed the maturity to support and illicit the new behaviour11.

The dynamic systems approach provides a holistic perspective to understanding motor

development11,19. As described by Bernstein’s contextual variations problem, a movement is a

response to a variety of biological and environmental variables. Together, the interaction

between these variables and the underlying subsystem dictates how the child responds and

generates appropriate movements. Given the support for the dynamic systems approach to motor

development, continued efforts are required to further understand the biological and

environmental factors that may influence motor development as well as identifying key

parameters that explain the behaviour of the system.

1.2.3 An Overview of Motor Development

Motor development is initiated during the embryonic stage of pregnancy and continues

well into adolescence11. Prenatal motor development begins at 5-6 weeks gestation as striated

muscles differentiate from the mesoderm23. As muscles differentiate, they react to direct

stimulation and produce movements known as myogenic movement11,24. Myogenic movement

begins with extension-like movements of the upper spine. At 8-9 weeks gestation, myogenic

10

movements include extensions of the arms and legs23. These jerky, uncoordinated fetal

movements, however, are only detectable through ultrasonography.

The fetal stage of pregnancy begins at 10 weeks gestation and is marked by the

completion of organ differentiation11. During the fetal stage, the fetus increases in size and by 13

weeks gestation, fetal movements are strong enough to be recognized by the mother25. Fetal

activity has been shown to increase in frequency through the first half of pregnancy, culminating

at 20 weeks gestation23. Following 20 weeks gestation, motor activity is reduced due to space

restrictions and fetal movements evolve from myogenic to neurogenic movements; movements

generated by the central nervous system11,23. The variation in fetal movement associated with the

latter half of pregnancy has also been shown to vary according to biological and environmental

factors. For example, motor activity during the third trimester has been shown to vary between

sexes, with males exhibiting increased movement compared with females23. Moreover,

extrauterine stimuli, such as sudden noises may also elicit fetal movement. Maternal smoking

has also been shown to reduce fetal movement; however, normal movement patterns are restored

during non-smoking periods23. Though the frequency of fetal activity decreases later in

pregnancy, the vigour of the movements increases.

Towards the end of the second trimester, neuromotor development is sufficient to begin

supporting primitive reflexes26. Primitive reflexes are complex, brainstem-mediated, automatic

movement patterns that are present at birth and initiated by specific stimuli27,28. The development

of these reflexes support the survival of newborns by enabling feeding or avoiding harm11,25,28.

For example, the rooting reflex is initiated by stimulating the baby’s cheek. Following

stimulation, the baby will respond by rotating their head in the direction of the stimulus. This

reflex supports the baby in locating the nipple during feeding28. The rooting reflex is

11

complemented by the sucking reflex that is initiated once an object enters the baby’s mouth.

Though some primitive reflexes exhibit clear survival origins, the purpose of other reflexes, such

as the Moro reflex, remains unclear and may be artifacts of our evolutionary past28.

As the central nervous system matures, voluntary movement is initiated and most

primitive reflexes become increasingly hard to elicit27. After 12 months postpartum, most

primitive reflexes are non-existent and will not be exhibited by neurologically intact children or

adults. The persistence or reappearance of these reflexes may be indicative of immaturity of the

nervous system or neurologic disorders23. As such, testing for these reflexes is integral to clinical

neurologic assessments throughout the life course.

Beginning at 2-3 months of age, infants develop the ability to maintain their posture

following environmental changes through the acquisition of postural reflexes11. Postural reflexes

are automatic movements that include righting reflexes, reflexes that enable the body to return to

its normal position following a movement, and equilibrium reactions, movements that restore the

centre of gravity following movement. These reflexes are distinct from primitive reflexes as they

involve multiple input modalities and require cortical integrity29. Moreover, though postural

reflexes support the development of later voluntary movement, they remain neurologically and

developmentally distinct from voluntary control11.

The final group of reflexes that exist prior to voluntary movement are locomotor reflexes

that are exhibited beginning at birth through 3-5 months of age11. Though locomotor reflexes are

insufficient to support locomotion, they resemble movements such as crawling, swimming and

stepping. Each of the reflexes are elicited in response to a specific stimulus, such as the stepping

reflex that occurs if the baby’s foot is placed on a flat surface with their body weight forward11.

12

Voluntary movements begin during the first 6-months of development and typically

conform to three general principles: 1) cephalocaudal development, 2) proximodistal

development, and 3) differentiation28. Cephalocaudal development refers to the progression of

development from the head towards the coccyx. Through the first 6-months of development,

coordination and movement are refined beginning with the head and neck, and later the arms and

hands. The subsequent 6 months includes the development of the trunk, arms and legs. The

cephalocaudal principle of development is complemented by the proximodistal principle of

development. The proximodistal principle suggests that motor development is refined beginning

at the centre of the body and progresses towards the extremities. As such, increased coordination

begins with the upper arm, followed by the forearm, hands and then fingers. Similarly,

coordination of the upper leg precedes coordination of the lower leg, feet and toes. Together, the

cephalocaudal and proximodistal principles describe the general patterns of motor

development28. The emergence of mathematical models involved in the dynamic systems

approach to motor development suggest, however, that some deviation from these patterns may

exist30.

The principle of differentiation suggests that motor development progress from general

movements to increasingly specific movements28. Early in development, responsive reactions

may elicit movements involving the entire body. Through development, however, these reactions

will become less generalized and movement of the extremities will become more purposeful.

Together, these principles provide an overview of the progression of motor development.

Motor development typically begins with gross motor movements of the head and trunk. As

gross motor movement extends to the extremities, fine motor movements are subsequently

refined.

13

1.2.3.1 Gross motor development

Gross motor skills are defined by the American Psychological Association Dictionary of

Clinical Psychology as activities or skills that use large muscles to move the trunk or limbs and

control posture to maintain balance31. The development of these skills begins with postural

control and the ability to control the head and neck11. Given the proportions of the head relative

to the body, infants cannot fully control the movement of their head until three months of age.

Conforming to the cephalocaudal principle of development, gross motor development

continues down the trunk as the infant develops the postural control to sit unsupported32,33. In

their study investigating the age of attainment of six gross motor skills across Ghana, India,

Norway, Oman and the United States, the World Health Organization (WHO) Multicentre

Growth Reference Study Group found that children began sitting without support at 6 months

(SD: 1.1 months; Table 1)32,33. Following sitting without support, postural control of the legs was

recorded to begin at 7.6 months of age (SD: 1.4 months) with the infant’s ability to stand with

assistance.

Table 1: Mean age for the attainment of six gross motor milestones (table adapted from

WHO Multicentre Growth Reference Study Group: WHO Motor Development Study32,33)

Gross Motor Milestone Mean age in monthsa (SD)

Sitting without support 6.0 (1.1)

Standing with assistance 7.6 (1.4)

Hands-&-knees crawling 8.5 (1.7)

Walking with assistance 9.2 (1.5)

Standing alone 11.0 (1.9)

Walking alone 12.1 (0.8) a The calculation in months involves the division of the estimate in days by 30.4375

14

The onset of locomotion begins with creeping, a rudimentary form of crawling where the

infant pushes themselves around while remaining on their stomach11. As the baby’s strength and

coordination improves, they begin to exhibit hands-and-knees crawling at 8.5 months of age

(SD: 1.7 months; Table 1)32,33. As described by the WHO Multicentre Growth Reference Study

Group, upright locomotion is typically not observed until 9.2 months of age (SD: 1.5 months),

when the child begins to walk with assistance. Walking with assistance, or cruising, begins with

the infant supporting themselves using both arms and legs11. This assisted movement refines the

infant’s postural skills eventually leading to unassisted walking by 1-year of age (mean: 12.1

months; SD: 0.8 months)32,33. The early steps in walking are supported by a wide stance and

uncoordinated, flat-footed steps11. With practice, the child’s stance narrows, increasing the

length of strides and allowing walking speeds to vary. The increase in stride length is supported

by the movement of arms, where opposite arm and legs move forward together25.

Children’s ability to walk and run is continuously refined until 5-6 years of age. At two

years of age, toddlers begin to exhibit a rudimentary running style that is characterized by stiff

legs and a lack of airborne time between each step25. By school-age, however, most children can

run, vary their speed and quickly change directions.

1.2.3.2 Fine motor development

Fine motor skills are defined by the American Psychological Association Dictionary of

Clinical Psychology as activities or skills that require coordination of small muscles to control

small, precise movements, particularly in the face and hands34. Fine motor development in the

face includes the refinement of visual-motor control. Beginning as early as 36 weeks gestation

eye movements are detectable35 and by 2 months of age, infants develop the ability to visually

15

track objects. Closely interconnected with visual function and attention, infants’ ability to track

objects assists the development of later fine motor movements, such as reaching and grasping.

Moreover, the synchronization of the hands and feet with the eyes assists infants in coordinating

movements with their dynamic surrounding environment11.

As the child ages, fine motor development progresses in a similar cephalocaudal and

proximodistal pattern as gross motor development. By 4 months of age, infants develop the gross

motor skills required to begin reaching for objects11,25. Early reaching, however, is characterized

by a series of jerky, uncoordinated movements25. The progression of fine motor development,

along with improved proprioception, supports reaching behaviours in becoming smoother and

more coordinated movements.

In addition to reaching, the child also must develop the skills necessary to grasp an

object11,25. Infants are born with a palmar grasping reflex where the fingers will curl around and

grasp an object that has stimulated their palm28. This reflexive grasp is strong enough to support

the infants weight, however, remains under involuntary control. As such, the reflexive grasp only

releases upon muscle fatigue. The transition between reflexive grasping to voluntary grasping

begins between 4-8 months of development25. During this transition, the infants will begin to

include their thumb when grasping and orient their hand in a direction to best grasp the object of

interest.

Together, the fine motor skills involved in reaching and grasping require many years to

become highly coordinated. Between 4-6 months of age, a child develops the ability to

manipulate each arm and hand individually25. By two years of age, the child is able to discern if

an object will require one or two hands to be manipulated, and elicit the appropriate action.

Moreover, between 2-3 years of age, the child begins to elicit coordinated actions involved in

16

dressing themselves, such as putting on clothes and using zippers. Intricate fine motor skills such

as fastening buttons or tying shoes, however, only emerges between 5-6 years of age25.

In sum, motor development is initiated during pregnancy and development is continuous

throughout childhood11,23,25,28. The emergence of fine and gross motor skills typically progress in

a cephalocaudal and proximodistal pattern11,25,28. Though the pattern and sequence of

development have been described, motor development is marked by considerable variability

between individuals.

1.2.4 Developmental Assessment Tools

As described above, the course of neurodevelopment is orderly, cumulative, and

directional8,9; however, developmental delays are common1,2. A recent American cross-sectional

study reported that 15%, or nearly 10 million children aged 3-17 years had a developmental

disability in 2006-200836. The identification of children experiencing developmental delays is

imperative as delays in early childhood development may be indicative of underlying neurologic

conditions or chronic developmental disabilities37. Moreover, evidence suggests that early

intervention strategies are effective at mitigating potential long-term repercussion of transient

developmental delays, thereby optimizing the outcomes of children38. As such, systematically

assessing child development has been proposed as an approach for identifying developmental

delays in childhood. To assess child development, two forms of testing exist: screening tests or

diagnostic tests. Screening tests aim to detect early disease or risk factors for a disease in an

asymptomatic individual38. The results of the test provide an estimate of the level of risk an

individual has for a disease and are used to determine if a diagnostic test is warranted. To avoid

missing any potential diseases, screening tools include cut-off scores for differentiating between

17

diseased and non-diseased individuals that are selected towards high sensitivity. As screening

tools are designed to assess the development of many individuals, they are generally affordable

and non-invasive. Contrarily, diagnostic tests aim to determine whether a symptomatic or

asymptomatic individual with a positive screening test result truly has a disease38. As diagnostic

tests are intended to limit the number of false positive diagnoses, diagnostic criteria are selected

towards high specificity.

In this section, the characteristics of developmental screening tools will be discussed. To

accurately measure development throughout childhood, assessment tools have been developed

that vary according to the reference used to evaluate a child’s development, the developmental

domains that are examined, and who assesses the child.

To evaluate a child’s progression through development, their attainment must be

compared with a reference point to determine if the child is progressing typically or if they are

experiencing possible delays11. To do so, two reference scales are commonly used in assessment

tools: 1) criterion-referenced tools, and 2) norm-referenced tools11,40. Criterion referenced tools

compare a child’s proficiency in a skill with an external criterion that may or may not be

standardized to a reference group. This comparison format provides a clear indication of what a

child can and cannot perform. As the external criterion may not be standardized, criterion-

referenced assessment tools are scored using absolute standards, where perfect scores are

desired40. Given this scoring structure, criterion-referenced assessment tools are particularly

useful in assessing child development longitudinally or following an intervention as scores are

reflective of the child’s ability, rather than the child’s ability compared with a reference

population. Though few developmental assessment tools are exclusively criterion-referenced

18

based, the Brigance Screens tool provides both criterion-referenced and norm-referenced

developmental scores40,41.

Norm-referenced assessment tools compare a child’s ability with a representative group40.

This style of comparison is more common among developmental assessment tools as scores can

be compared with age-adjusted means and standard deviations to assess if a child is progressing

typically or exhibiting possible delays. Though commonly used, norm-referenced tools have

been criticized. The comparison of child development relative to a reference group fails to

account for the variability in rate and sequence of development exhibited by children11. As such,

assessment tools are not applicable for establishing a diagnosis for a child. Rather, assessment

tools inform professionals whether the child is in need of more in-depth monitoring39,42.

An additional criticism of norm-referenced tools is generalizability11. Given the influence

of biological and environmental factors on development, norm-referenced tools are only

applicable to children whose characteristics are represented in the reference population. For

example, the Ages and Stages Questionnaire, 2nd edition was standardized based on a group that

varied educationally, economically and ethnically41. This population, however, was not

nationally representative of the United States of America and therefore appropriate caution must

be taken when utilizing this scale to ensure the standard sample reflects the participants

appropriately.

Developmental assessment tools also vary according to developmental domains they

assess. Many of the developmental assessment tools used in research assess multiple

developmental domains. For example, the Bayley Scales of Infant Development, 3rd edition

measures two composite scores, language and motor, using six subscales: 1) cognitive, 2)

receptive communication, 3) expressive communication, 4) gross motor, 5) fine motor, and 6)

19

social-emotional41. Other developmental assessment tools, however, only measure a single

domain. These include tools such as the Alberta Infant Motor Scale, that exclusively assesses

motor development from birth to 18 months of age43.

Further to variations in comparison groups and developmental domains assessed,

assessment tools also vary according to the type of assessor required to complete the tool. Tools

such as the Ages and Stages Questionnaire have been designed such that the primary caregiver of

the child can sufficiently complete the assessment41. The Bayley Scales of Infant Development,

however, must be completed by trained professionals. Traditionally, it was believed that parents

of children with disabilities tended to overestimate their child’s abilities and, therefore, scales

completed by professionals were preferred44. A study by Harris, however, described that

compared with standardized tests, parents were adept at identifying developmental delays

(sensitivity: 80.0%; specificity: 90.9%)44. Moreover, Bodnarchuk and Eaton also reported that

parental assessment of gross motor milestone attainment had strong agreement with the results

reported by trained professionals45.

In addition to the variability of the structure of developmental assessment tools, the

quality of each tool also varies. To measure the quality of an assessment tool, their estimated

reliability and validity are measured11. The reliability of assessment tools is a measure of how

well a tool can produce consistent results when repeated. For assessment tools, reliability is

generally measured through two tests: 1) intrarater reliability and 2) interrater reliability11.

Intrarater reliability measures the consistency of the results following a single assessor

administering the assessment repeatedly to an individual under constant conditions. Interrater

reliability, however, measures the agreement or correlation between the results obtained when

20

two different assessors administer the assessment to the same individual. For a developmental

assessment tool to be useful, there must be a high degree of intrarater and interrater reliability.

Validity of a developmental assessment tool measures the tool’s ability to accurately

measure the developmental domain of interest11. For infant developmental assessment tools,

validity is measured according to context, construct and criterion-related validity. A tool is said

to have high context validity if it appropriately measures the developmental domain of interest.

For example, if a developmental tool is used to investigate fine motor development, it would

have high context validity if the assessment included fine motor skills relevant to the age group

under investigation.

Construct validity of an assessment tool measures if the tool appropriately evaluates the

performance of the task of interest11. Through this measure, a tool is said to have high construct

validity if it can differentiate between two groups with known differences in capabilities.

Finally, criterion-related validity measures how well the tool works in comparison with

the gold-standard tool currently in practice11. To measure criterion-related validity, both

concurrent and predictive validity are measured. Concurrent validity measures the assessment

tool’s ability to predict a child’s development relative to the optimal tool currently in practice.

Predictive validity, however, measures the tools ability to accurately predict a long-term

outcome. For example, whether an assessment tool for motor development administered at two

years of age can accurately predict a child’s school grade in physical education at five years of

age.

21

1.2.5 Population-wide developmental screening and the importance of at-risk profiles

for developmental delays

The use of assessment tools to screen for disease is a practice that aims to reduce the

morbidity of disease through early identification and intervention45. To support the identification

of a myriad of diseases, countless types of screening tools have been developed and validated. In

practice, however, screening for all disease is inefficient as the cost of screening and potential

risk of over-referring patients may tax the available healthcare system with no significant benefit

to the population or individuals. As such, in 1968 the World Health Organization put forward ten

guiding principles for early disease detection: 1) the condition sought should be an important

health problem; 2) there should be an accepted treatment for patients with recognized disease; 3)

facilities for diagnosis and treatment should be available; 4) there should be a recognizable latent

or early symptomatic stage; 5) there should be a suitable test or examination; 6) the test should

be acceptable to the population; 7) the natural history of the condition, including development

from latent to declared disease, should be adequately understood; 8) there should be an agreed

policy on whom to treat as patients; 9) the cost of case-finding (including diagnosis and

treatment of patients diagnosed) should be economically balanced in relation to possible

expenditure on medical care as a whole; and 10) case-finding should be a continuing process and

not a "once and for all" project45. Together these principles aim to support the healthcare

community in identifying disease whose morbidity may be reduced through screening.

When applying the WHO’s principles for early disease detection, there is support for

screening children with developmental delays. For example, as one of the most common

childhood disabilities, developmental disabilities are an important health problem2. To identify

delays, reliable and valid screening tools that can be administered in the home or at well-baby

22

physician visits have been designed to screen child development11,41. Moreover, given the long-

term implications associated with developmental delays, such as learning and behavioural

difficulties or later functional impairment, untreated developmental delays have the potential to

significantly tax the healthcare system46. What currently lacks to support a population-based

screening strategy for developmental delays is evidence supporting acceptable treatments for

those with delays. Consequently, in 2016 the Canadian Task Force on Preventive Health Care

was called to assess the evidence for effectiveness of population-based screening in primary care

settings for children aged 1-4 years46. The goal of this review was to address if the health

outcomes of children who would go unidentified through standard clinical practice could be

improved through population-based screening. To do so, the evidence of the benefits and harms

of developmental screening and treatment were reviewed.

The results of their systematic review informed their recommendation against screening

for developmental delay using standardized tools in children aged one to four years with no

apparent signs of delay, and whose parents or clinicians have no concerns about development46.

This recommendation, however, does not apply to children who present with signs or symptoms

that could indicate developmental problems, or whose development is being closely monitored

because of identified risk factors.

Given the Canadian Task Force on Preventative Health Care’s recommendation,

identification of children with developmental delays remains the responsibility of primary

caregivers and health care providers. To successfully identify children with developmental

delays, a strong relationship between primary caregivers and health care providers is required38.

Studies have reported that when questioned systematically about their child’s development,

primary caregivers provide accurate information and can identify delays38. Additionally, primary

23

care providers may also play an instrumental role in the identification of children with delays

given their longitudinal relationship with their patients. Through this longitudinal relationship,

primary care providers may recognize biological, sociodemographic or environmental factors

influencing a child’s development. If care is infrequent or discontinuous, however, factors

influencing development may go unrecognized and developmental delays unnoticed. As such, to

support Canadian primary caregivers and health care providers in assessing potential risk factors

for delayed development, it is imperative to inform a contemporary at-risk profile for

developmental delays15. An at-risk profile for Canadian children will ensure questions posed to

caregivers concerning a child’s development are relevant and evidenced-based. Furthermore, an

at-risk profile will inform health care providers of risk factors for developmental delays that

require assessment during healthcare visits.

Ultimately, by developing a contemporary at-risk profile for developmental delays,

diagnosis may be made early in development, maximizing the outcomes of therapy and

minimizing families’ stress5,38.

1.3 Research Objectives

1. To determine factors associated with delayed fine motor development at 24 months of

age.

2. To determine factors associated with delayed gross motor development at 24 months of

age.

24

1.4 Research Significance

Motor development may be among the first symptoms of global development delay or

delays in cognitive development5,37. By discerning critical risk factors, our study aims to inform

the development of a contemporary at-risk profile for both delayed fine and gross motor

development. The development of these at-risk profiles will support clinicians and caregivers of

young children in identifying children at increased risk of delayed motor development. As

complications in motor development may be indicative of global developmental disabilities5, the

identification of children at risk of delays may enable earlier access to instructed physical

activity sessions such as well-resourced play environments supported by teachers or trained staff.

Earlier access to these interventions may increase their effectiveness4 and ultimately optimize

outcomes for children and families.

Additionally, this study will contribute to the few Canadian studies currently existing in

the literature. As children of different countries are exposed to different factors such as cultural

expectations of motor skills, poverty, poor healthcare accessibility and different physical

environments47, research targeting Canadian children is essential to support the development of a

relevant at-risk profile of motor development delays. Using data from the All Our Families

(AOF) cohort, a longitudinal pregnancy cohort with detailed information about maternal and

infant demographics, lifestyle, mental health, family life and development during the perinatal

and early childhood period, this study will elucidate risk factors for motor development delays

among Albertan children48.

25

1.5 Knowledge Translation

To support the identification of children with delayed motor development, the results

from this study will be disseminated to community partners, health care providers and

educational institutions.

Community partners, such as the First 2000 Days Network, Alberta Health Services

Parenting Support, the Alex Centre and Parent Link Centre have a goal of informing the pregnant

and parenting population of healthy parenting practices and child development. As such, it is

important to advise these organizations of the novel findings, especially as they relate to

Canadian children. To ensure these organizations are informed, the results will be presented at

the organizations’ meetings and included in the All Our Babies/Families annual reports.

Furthermore, efforts will be made to investigate if local organization are interested in publishing

these results in their own resources, such as their website or newsletter. Knowledge translation

initiatives targeting the general populace will include disseminating results via the All Our

Families Study website and social media accounts. Parent participants will be notified of results

via All Our Families study newsletters.

To inform policymakers and primary health care providers of the implications of this

study, these results will be disseminated via peer-reviewed publications and presented at

scientific meetings related to maternal and child health. Networking efforts will be made to

ensure professors and staff at education institutions such as the Bachelor of Child Studies

program at Mount Royal University are aware of these results. By informing professors and staff

of our results, the risk and protective factors associated with delayed motor development at 24

months of age may be discussed with future child care providers and child health experts.

26

By informing stakeholders involved in early child development, children with increased

risk of motor delays may receive earlier and more effective interventions, ultimately optimizing

their developmental outcomes.

1.6 Summary of Thesis Format

This thesis is composed of five chapters. This chapter provided an overview of the

background related to child development and tools used to assess development. Chapter two

summarizes a systematic review of the literature investigating risk and protective factors related

to motor development. Chapter three provides a detailed account of the methodology used to

identify and test factors related to both fine and gross motor development. Chapter four presents

the results from the analysis of risk and protective factors influencing motor development in

children two-years of age. Chapter five provides a summary of the results, their practical

implications and suggestions for future research.

27

CHAPTER TWO: REVIEW OF THE LITERATURE INVESTIGATING FACTORS

ASSOCIATED WITH GENERAL, FINE AND GROSS MOTOR DEVELOPMENT

2.1 Methods

2.1.1 Data Sources and Search Strategy

A literature search was performed using CINAHL (1982-June 2, 2016), EMBASE (1980

– June 2, 2016), HealthSTAR (1975 – June 2, 2016), MEDLINE (1946 – June 2, 2016) and

PsycINFO (1803-June 2, 2016). Databases were search using the following keywords: “risk

factor”, “protective factor”, “marker”, “predict*”, “determinant*”, “correlate*”, “associate*”,

“motor development”, “delayed motor development” and “motor skill”. The following search

queries were performed:

1) “Risk Factor” or “Protective factor” or “Marker” or “Predict*” or “Determinant*”

or “Correlate*” or “Associat*”

2) “Motor Development” or “Delayed Motor Development” or “Motor skill”

3) “Search query #1” and “search query #2”

The literature identified using the aforementioned search strategy underwent a title and

abstract review for relevant articles. Each article then underwent a full-text review, where those

that failed to meet the inclusion or met the exclusion criteria were excluded. Bibliographies of

select articles were also reviewed to identify other relevant publications. The results of the

screening process are summarized in (Figure 1).

2.1.2 Inclusion Criteria

Inclusion criteria are as follows: 1) English articles; 2) articles published in a peer-

reviewed journal; 3) studies that assessed gross or fine motor development using validated

28

scales; and 4) human participants between 1-66 months of age (if age not reported, standard

regional age range for a given school grade was used to determine eligibility – e.g. Kindergarten

in Alberta = 5 years of age). The age range of 1-66 months was selected as validated

developmental scales (e.g. Ages and Stages Questionnaire, Bayley Scales of Infant Development

and Peabody Developmental Motor Scales) typically assess development up to a maximum of 66

months of age41. By including studies within this age range, a comprehensive list of risk factors

could be identified and their potential influence on motor development at 24-months of age can

be explored.

2.1.3 Exclusion Criteria

Exclusion criteria are as follows: 1) non-analytic designs; 2) studies with less than 30

participants; and 3) studies conducted in middle and low income countries. Studies with sample

sizes less than 30 participants were excluded as these studies may not contain sufficient power to

reject false null hypotheses. Studies conducted in middle income and developing countries were

not included due to potential differences in children’s exposure to risk factors such as cultural

expectations of motor skills, poverty, malnutrition, poor health, and different physical

environments47.

2.1.4 Data Extraction and Synthesis

The study design, study population, the screening tool used to assess motor development

and the results from relevant articles were extracted. Data are summarized in Table 2 and 3, to

highlight the risk factors for either general, fine or gross motor development.

29

2.2 Results

Of the 6358 original articles identified, 142 articles were selected for full-text review

(Figure 1). Twenty-six articles were excluded following full-text review as they were either

conducted in middle income or developing countries, children were assessed at ages beyond the

scope of this review or the articles did not segregate motor development in their investigation of

neurodevelopment.

Figure 1: Overview of included and excluded articles

30

Given the multitude of screening tools available, motor development has been assessed

using three classifications: 1) general motor development, 2) fine motor development and 3)

gross motor development. Here, the socio-demographic, maternal health, pregnancy and birth

outcome, child health, and child environmental risk factors identified from the literature will be

described for each definition of motor development.

2.2.1 Risk Factors for Delayed General Motor Development

A summary of the included articles assessing general motor development are presented in

Table 2.

31

Table 2. Summary of articles examining factors associated with general motor development in children 1-66 months of age

Author

(Year)

Study

Design Study population

Neurodevelopment

Test Factors investigated

Results related to motor

development

Abbott et

al., 200049

Prospective

cohort study

Convenience sample of

43 English-speaking

mother-baby dyads.

Infants were aged 6

weeks-5 months.

Intended care for the

infant was in the home

for their first 8 months

(at least 4 days a week).

- Alberta Infant

Motor Scale (AIMS)

at 8 months of age.

- Assessed general

motor development

- HOME Inventory Scale

- Parental expectations (Maternal

version of AIMS scale: MAIMS)

- Infant general health and mood

- Any health conditions

- How infant practiced new

activities

- equipment used by infant

- if infants enjoyed playing on the

floor

- No significant correlations between

HOME Inventory and motor

development

- No significant relationships found

between parental expectations of

development at 5 months and actual

motor development at 8 months

Abbott &

Bartlett,

200050

Prospective

cohort study

Convenience sample of

43 English-speaking

mother-baby dyads.

Infants were aged 6

weeks-5 months.

Intended care for the

infant was in the home

for their first 8 months

(at least 4 days a week).

- Alberta Infant

Motor Scale (AIMS)

at 8 months of age.

- Assessed general

motor development

- Equipment used by infant during

play

- Significant correlations were found

between total equipment use and

motor development

- Significant correlations between use

of exersaucer, highchair and infant

seat and motor development

- No correlations found for jolly

jumper, walker, playpen, infant swing

and the other category

Aiello &

Lancaster,

200751

Prospective

cohort study

Sample of 71 adolescent

mother-infant dyads

recruited antenatally in

southeastern

Melbourne, Australia.

Infants were 41male

and 30 females.

Mothers were first-time

mothers, proficient in

English, absent of

intellectual disabilities,

- Bayley Scales of

Infant Development,

2nd edition at 2 years

of age.

- Assessed general

motor development

- Adolescent’s Separation-

individuation Process Inventory

- Adolescent’s Maternal Postnatal

Attachment Scale

- Adolescent’s Maternal

Separation Anxiety Scale

Adolescent’s Parental Bonding

Instrument

- Demographics (age, ethnicity,

relationships, living arrangements,

pregnancy history)

- Significant correlations with motor

development: living arrangements

(living with parent/s in early

postpartum correlated with poor

motor performance), infant age at

assessment,

- No correlations found with: infant

gestational age or sex, mother care,

mother overprotection, separation-

individuation, maternal-infant

attachment or maternal separation

anxiety.

- The proportion of variance in motor

32

Author

(Year)

Study


Neurodevelopment



development

development was not significantly

predicted by any of the factors

Arendt et

al., 199852

Prospective

cohort study

A sample of 167 12-

month olds and their

mother were recruited

and assessed. Mothers

were over 17 years of

age and did not have

any of the following:

psychiatric problems,

low intellectual status,

HIV positive, positive

drug test for PCP,

amphetamines,

barbiturates or heroin.

Infants weighed more

than 1500 grams at

birth.

- Bayley Scales of

Infant Development,

2nd edition at 12

months of age

(assessed general

motor development)

- Movement

Assessment of Infants

- Test of Sensory

Functions in Infants

- Infant Behavior

Record of the Bayley

Scales of Infant

Development

- Maternal and infant demographic

and medical characteristics

(maternal age, race, gravidity,

number of prenatal visits, type of

medical insurance, APGAR score,

gestational age, gender, head

circumference birth weight and

length

- Maternal Postpartum Drug

Interview

- When gestational age was covaried,

cocaine exposure displayed a trend

for lower psychomotor scores

- No confounders correlated with the

Bayley Scales of Infant Development

- Maternal age was correlated with

Movement Assessment of Infants

scores

- Primitive reflex scores were

correlated with number of cigarettes

and number of drinks per week

- Automatic reactions were correlated

with maternal age and number of

prenatal visits

- Regression results for Test of

Sensory Functions in Infants:

Adaptive Motor predicted by number

of prenatal visits; Tactile

Responsivity and Visual-Tactile

Coordination predicted by severity of

cigarette use;

- Regression results for Movement

Assessment of Infants: Primitive

reflexes predicted by severity of

cigarette use

- Regression results for Infant

Behavior Record of the Bayley

Scales of Infant Development:

Activity predicted by maternal age,

number of prenatal visits, parity

Astley et

al., 199053

Prospective

cohort study

A sample of 136

mother-child were

enrolled. 68 infants

were exposed to

marijuana via lactation

- Bayley Scales of

Infant Development,

1st edition at 1 year of

age

- Alcohol, tobacco and other drugs

use, demographic characteristics,

obstetric characteristics, lactation

status, use of supplemental

formula during lactation

- Infants exposed to marijuana for the

first month of lactation had

significantly lower mean

psychomotor scores than infants with

no marijuana exposure

33

Author

(Year)

Study


Neurodevelopment



development

and 68 were unexposed. - Assessed general

motor development

- Covariates: maternal age, height,

race, income level, education,

marital status, pregnancy history,

weight gain, tobacco, coffee,

alcohol and psychoactive drug use

during pregnancy and lactation,

marijuana use during pregnancy,

paternal alcohol and tobacco use

during conception and during

postpartum period, gestational age

and sex

- Exposure to cocaine via breastmilk

or alcohol during gestation also had a

significant adverse effect on

psychomotor development

Aylward et

al., 199254

Prospective

cohort study

A sample of 45

seronegative HIV

infants, 12 seropositive

HIV infants and 39

seroreverter HIV infants

between the ages of 5.5-

24 months of age were

enrolled. Infants were

excluded if they

weighed less than 1500

grams at birth, were less

than 34 weeks’

gestation or were

admitted to the neonatal

intensive care unit for

longer than 24 hours.

- Bayley Scales of

Infant Development,

1st edition at 6-, 12-,

18-, 24-months of age

- Assessed general

motor development

- Substance abuse in utero - Seropositive infants score

significantly lower on psychomotor

development than non-infected

infants

- No significant difference in

psychomotor scores among infants

exposed to substance abuse in utero

and non-exposed infants

Bedford et

al., 201655

Cross-

sectional

study

A sample of 715 UK-

based parents of 6- to

36-month-old children

were enrolled.

- Milestones adapted

from standardized

assessment tools.

- Demographic information

(child’s age, sex, maternal

education)

- Touchscreen usage (number of

devices in home, child’s number

of devices, frequency of use, age

at first use)

- Controlled variables: early

developmental milestones, maternal

education and, infant age and sex.

- No significant associations found

between gross motor (walking) and

language (combining two words)

milestones and touchscreen use

- Significant association between fine

motor milestone attainment (staking

blocks) and touchscreen use

34

Author

(Year)

Study


Neurodevelopment



development

- Age of first use and age of devices

was associated with staking blocks

Belfort et

al., 201156

Prospective

cohort study

A sample of 613 infants

born <33-weeks’

gestation from the DHA

for Improvement of

Neurodevelopmental

Outcome trial.

- Bayley Scales of

Infant Development,

2nd edition at 18

months of age

- Assessed general

motor development

- Infant Anthropometry: infant

weight and length, head

circumference,

- Demographic and clinical

information (gestational age,

breastfeeding, NICU diagnoses,

postnatal steroids exposure,

maternal smoking during

pregnancy, parental education)

- Home Screening Questionnaire

- Greater weight gain from first week

postpartum to gestation age 40 weeks

was associated with higher Bayley

Scales of Infant Development scores

- From term to 4 months of age,

greater weight gain and linear growth

were associated with higher

psychomotor development scores (no

associations found with BMI or head

growth)

Bendersky

& Lewis,

199457

Prospective

cohort study

A sample of 175

families were recruited.

Eligibility require the

infant weight 2000

gram or less at birth and

were treated in the

neonatal intensive care

unit.

- Bayley Scales of

Infant Development,

1st edition between

18-24 months of age

> Assessed general

motor development

- Sequenced

Inventory of

Communication

Development

- Perinatal and demographic

variables collected from maternal

obstetrical and infant neonatal

medical records

- Medical complications score

(number of common

complications of prematurity)

- Environmental Risk Variables

(parental education and

occupation, minority status,

number of children under 18 years

of age living in house, parents

living together, positive stressful

life events, negative stressful life

events, HOME Interview, social

support, quality of mother-child

interaction)

- None of the environmental risk

variables made significant

independent contributions to the

psychomotor score (3.9% of

explanatory power of the variance)

- Intraventricular hemorrhage and

medical complications scores were

significantly related to psychomotor

scores.

- Mental developmental index was

predicted by both environmental and

biological risk variables.

- Receptive communication was

explained more by environmental risk

variables than early medical

conditions

- Variance in expressive language

was minimally explained by

environmental and biological risk

variables

Black &

Nitz,

199658

Cross-

sectional

study

A sample of 79

adolescent mothers and

their child were

recruited. Among the

infants, 37 were

- Bayley Scales of

Infant Development,

1st edition (mean age

of children = 12.4

months, SD = 5.7

- Grandmother co-residence

- Perceived Stress

- Perceived family support

- Maternal perception of children’s

temperament

- Maternal education, parity and

mealtime competence was associated

with motor development

- Within the failure to thrive group,

grandmother co-residence was

35

Author

(Year)

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Neurodevelopment



development

categorized at failure to

thrive and 42 had

adequate growth.

months) - Parental warmth and children’s

competence during mealtime

associated with poorer motor

development

- Within the adequate growth group,

grandmother co-residence was

associated with increased motor

development

Brown et

al., 201059

Prospective

cohort study

A sample of 10700

children were recruited

in the Early Childhood

Longitudinal Studies –

Birth Cohort.

- Bayley Short Form

– Research Edition at

9 and 48 months

(assessed general

motor development)

- Age at assessment, poverty,

race/ethnicity

- Maternal alcohol consumption

per week during pregnancy

- Nursing Child Assessment

Teaching Scale

- Behavior Rating Scale

- Infant/Toddler Symptoms

Checklist

- Age and ethnicity (Black or Pacific

Islander) associated with increased

motor subscale scores

Casper et

al., 201160

Prospective

cohort study


from mothers who took

selective serotonin

reuptake inhibitors

major depressive

disorder in pregnancy.

Thirty-eight mothers

were recruited before or

early in pregnancy and

17 directly postpartum.

- Bayley Scales of

Infant Development,

2nd edition between

12-40 months of age

- Assessed general

motor development

- Confirmation of major

depressive disorder, Beck

Depression inventory, Hamilton

Depression Scale and Centre for

Epidemiological Studies –

Depression Scale

- Sociodemographic information, a

medical, family, and psychiatric

history and information about the

index pregnancy

- Neonatal and obstetrical records

- Antidepressant use (dosage and

type)

- Use of alcohol and smoking

- Increased length of antidepressant

exposure significantly increased the

odds of low Apgar scores

- Activity/muscle tone subscale of

Apgar score significantly reduced by

longer antidepressant exposure

- Psychomotor Developmental Index

and Behaviour Rating Scale scores

were negatively correlated with

increased duration of antidepressant

exposure

- Infants with early exposure were

rated significantly higher on

psychomotor development than

infants with continuous exposure

- Apgar scores did not significantly

predict psychomotor development or

behaviour rating scale

- Psychomotor development was

positively correlated with Behaviour

rating scale scores

36

Author

(Year)

Study


Neurodevelopment



development

Cohen et

al., 201161

Prospective

cohort study

A sample of 229

children were recruited

into the

Neurodevelopmental

Effect of Antiepileptic

Drugs study. Pregnant

women with epilepsy

were on monotherapies,

and had IQs above 70,

no history of syphilis,

HIV progressive

cerebral disease or other

major diseases. Mothers

also were compliant

with prescription and

were not taking any

other known teratogen.

- Bayley Scales of

Infant Development,

2nd edition between

36-45 months of age

- Assessed general

motor development

Potential confounders: age,

education, employment,

race/ethnicity, seizure/epilepsy

types and frequency, antiepileptic

drug dosage, compliance and SES,

USA vs UK, preconception folate

use, use of alcohol, tobacco or

other drugs during pregnancy,

gestational age, birth weight,

breastfeeding, childhood medical

disease

- Maternal IQ: Test of Nonverbal

Intelligence-3rd edition, Wechsler

Abbreviated Scale of Intelligence,

National Adult Reading Test

- Antiepileptic Drugs:

carbamazepine, lamotrigine,

phenytoin, valproate

- Maternal IQ, standardized drug

dosage, gestational age at delivery

and site location were all

significantly related to psychomotor

scores.

- Higher doses of valproate and

carbamazepine were associated with

lower psychomotor scores and lower

adaptive performance ratings

- Adaptive performance ratings were

significantly higher in infants from

mothers receiving education beyond

high school

- Adjusted mean performance on the

BASC scales did not differ between

drug groups

- higher doses of valproate during

pregnancy reported with increased

problems with child’s social sills

- Valproate had significantly greater

percentage of children at risk for

ADHD than the national Centre for

Disease Control estimates

Daniels et

al., 200262

Prospective

cohort study

A sample of 1207

infants were randomly

selected from the

Collaborative Perinatal

Project. Children were

eligible if they were a

liveborn singleton, had

3-mL of maternal third

trimester serum, and

completed the Bayley

Scales of Infant

Development.

- Bayley Scales of

Infant Development,

1st edition at 8 months

of age

- Assessed general

motor development

- Exposure to Polychlorinated

Bisphenyls

- Covariates: maternal race,

education, socioeconomic index,

intelligence quotient, marital

status, prenatal smoking, pre-

pregnancy BMI, third trimester

serum triglycerides, total

cholesterol, and

dichlorodiphenyldichloroethylene

level, birth order, gestational age,

breastfeeding,

- No association between maternal

serum Polychlorinated Bisphenyls

and psychomotor development or

mental development

- Relationship between maternal

serum Polychlorinated Bisphenyls

not affected by individual or center-

level characteristics, maternal age,

BMI, SES or smoking status

Datar &

Jacknowitz,

Prospective

cohort study

A subset of 6750

singleton births, 625

- Bayley Short Form

– Research Edition at

- Twin type (monozygotic or

dizygotic)

- In total sample, very-low-birth

weight and moderately-low-birth

37

Author

(Year)

Study


Neurodevelopment



development

200963 twin pairs and 50 twins

and high-order births

were included from the

Early Childhood

Longitudinal Study –

Birth Cohort.

9 months and 2 years

of age

- Assessed general

motor development

- Birth weight and small-for-

gestational age

- Child height, weight, sex,

race/ethnicity, first birth, twin or

higher-order, gestational age,

- Maternal height, age, education,

marital status, household income,

US region, urbanicity, smoking or

alcohol use during pregnancy, at-

risk pregnancy, labour/delivery

complications,

- Prenatal Care Utilization Index

weight were significant

disadvantages to mental and motor

development at 9-months of age. The

effects persist for mental

development, but not motor

development at 2 years of age

- Within-twin analysis (control for

maternal and environmental factors)

show that very-low-birth weight is

associated with poor mental and

motor development at 9 months but

not 2 years. Moderately-low-birth

weight is associated with poor mental

development at 9 months also

- Within-identical twin analysis

(control maternal, environmental and

genetic factors) show birth weight is

not associated with mental or motor

development at 9 months or 2 years

- small-for-gestational age associated

with poorer mental and motor scores

across sample, however, no

association is found in within-twin

analyses

Dubek-

Shriber &

Zelazny,

200764

Cross-

sectional

study

A convenience sample

of 125 4-month old

infants were recruited.

Infants were born full-

term from

uncomplicated

pregnancies, had a birth

weight of at least 2.268

kg, had no chronic or

acute medical

conditions and between

4 months and zero day

to 4 months and 29 days

- The Alberta Infant

Motor Scale at 4

months of age

- Assessed general

motor development

- Position log: amount of time per

day on belly, back, seated, held or

other positions in hour increments

- Parent questionnaire: infant date

of birth, birth weight, race, gender,

current weight, length, number of

weeks of the pregnancy, general

information of the infant’s health

- None of the demographic factors

were predictive of infant’s ability to

achieve motor milestones. Prone

awake time, however, was predictive

of achieving 7 of 21 prone, 3 of 9

supine and 3 of 12 sitting milestones.

- With increasing difficulty of

milestone, greater percentage of

infants achieving the milestone had

increased prone awake time

38

Author

(Year)

Study


Neurodevelopment



development

old.

Espel et al.,

201465

Prospective

cohort study

A sample of 232

mother-baby dyads

were enrolled. Infants

were full-term,

singleton births.

Women were eligible if

they were less than 16

weeks pregnant, English

speaking, non-smokers,

over 18 years of age,

not taking steroidal

medication with no

evidence of alcohol or

drug use during

pregnancy

- Bayley Scales of

Infant Development,

2nd edition at 3, 6 and

12 months

postpartum

- Assessed general

motor development

- Birth outcomes: gestational age

at birth, parity, birth weight, Apgar

scores, past maternal health and

pregnancy related or birth

complications

- Potential confounders:

Race/ethnicity, cohabitation status,

maternal education, household

income, obstetrical risk, birth

order, birth weight and infant sex

- Gestational length

- Term status (early term=37-38

weeks, term=39-40 weeks, later

term=41 weeks, post-

term=41+weeks)

- Among infants born full-term (39-

40 weeks’ gestation) longer gestation

associated with higher mental and

motor development at 3, 6 and 12

months postpartum

- term infants score lower than late

term infants on mental development

at 3 months and motor development

at 12 months

- Early term infants scored lower than

term and late term on mental

development at 3 month, on both

mental and motor development at 6

months and on motor development at

12 months

Fanaroff et

al., 200666

Prospective

cohort study


with extremely low

birth weight (<1000

grams) were enrolled).

Bayley Scales of

Infant Development,

1st edition at 2 years

of age

- Assessed general

motor development

- Hypotension status

- Cerebral palsy diagnosis

- audiologic testing

- Symptomatic hypotension was

associated with lower psychomotor

development score, but not mental

development scores

- Adjusted models described an

association between delayed motor

development and hearing loss

Fetters &

Huang,

200767

Prospective

cohort study

A sample of 30 preterm

infants born very-low-

birth weight with white

- Alberta Infant

Motor Scales at 1, 5

and 9 months of age

- White matter disease:

periventricular white matter

lesions or severe hemorrhage

- Sleeping prone, even if not

exclusively, was positively associated

with motor development at 1, 5 and 9

39

Author

(Year)

Study


Neurodevelopment



development

matter disease, 21

preterm infants born

very-low-birth weight

without white matter

disease, and 17 term

infants. Preterm infants

were eligible if they

were born between 24-

31 weeks’ gestation.

- Assessed general

motor development

- Sex, race, gestational age

- Term status

- Sleeping, feeding and playing

position

months

- Prone sleeping preterm infants had

high motor scores only at 9 months

compared to the preterm infants with

white matter disease

- At one month, only prone sleeping

was associated with motor

development. At 5 months, sleeping

prone, playing prone and group

membership were associated with

motor development. At 9 months,

sitting for play and group

membership were associated with

motor development. Sitting for play

was negatively associated with motor

development.

Gilbert et

al., 201368

Cross-

sectional

study

A sample of 16595

children from the Child

Health Improvement

through Computer

Automation (CHICA)

system.

- Adapted questions

from the Denver

Developmental

Screening Test II

prior to 72 months of

age.

- Intimate partner violence

- Parental psychological distress:

adapted from the Patient Health

Questionnaire-2 and the

Edinburgh Postnatal Depression

Scale

- Child abuse concern

- Sociodemographic

characteristics: gender,

race/ethnicity, clinic, insurance

type, preferred language

- Parental report of both intimate

partner violence and parental

psychological distress was associated

with failure of at least one milestone

question in language, personal-social

and gross motor

- Intimate partner violence was

associated with poor language,

personal-social and fine motor

development

- Parental psychological distress was

associated with poor language,

personal-social, gross and fine motor

development

Hediger et

al., 200269

Cross-

sectional

study

A sample of 4621 US-

born singleton infants

between the ages of 2-

47 months were

enrolled.

- Derived from

Bayley Scales of

Infants Development,

the Gesell scale and

the Denver

Developmental

Screening Test

- Birth weight and gestation age

- Infant race/ethnicity, sex,

maternal parity, plurality, birth

order

- Muscularity: mid-upper arm

circumference, triceps skinfold

thickness,

- Univariate analysis suggested

significantly lower scores among the

following: Mexican-Americans and

“other race/ethnicity” compared to

non-Hispanic white, less than 11

years’ education, maternal age of 35

years or greater, child is male, child

40

Author

(Year)

Study


Neurodevelopment



development

between 2-47 months

- Assessed general

motor development

(motor and social

development

variable)

- Sociodemographic: type of

residency (metropolitan vs. non-

metropolitan), region of residence,

maternal age, maternal smoking,

education

was not first born, low birth weight

(<2500 grams) and less than 36

weeks’ gestation

- Multiple regression models: Lower

scores associated with higher birth

order, less than 11 years’ education,

maternal age of 35 years or greater,

preterm low birth weight and term

low birther weight. Higher scores

were associated with non-Hispanic

black and maternal age less than 19

years. Analysis stratified by sex.

- Age trends by sex: males reported

higher scores at age 2-3 months, but

scores were similar through the

remainder of the first year. Females

exhibited higher scores after the first

year.

Hinkle et

al., 201270

Prospective

cohort study

A sample of 6850

infants were selected

from the Early

Childhood Longitudinal

Study – Birth Cohort.

Analysis was limited to

singleton infants,

without major structural

or genetic congenital

anomalies.

- Bayley Scales of

Infant Development,

2nd edition at 20-38

months of age

- Assessed general

motor development

- Maternal pre-pregnancy BMI

- Additional variables: maternal

age, race/ethnicity, parity, marital

status, education, smoking during

last trimester of pregnancy,

diabetes before or during

pregnancy, chronic or gestational

hypertension, child’s sex,


household income, number of

residents in household, gestational

weight gain, breastfeeding,

- Mental development scores were

lower among children of pre-pregnant

obese class II and III mothers,

compared to children of pre-pregnant

normal BMI mothers

- The risk of delayed mental

development was increased among

children born to underweight or

severely obese mothers than among

those born to normal weight mothers

- Psychomotor development did not

vary according to pre-pregnancy BMI

status of mothers

- Significant differences were

observed in mean mental and motor

scores for the following: maternal

ethnicity, maternal marital status

(lower if unmarried), maternal

education, maternal parity (lower if

41

Author

(Year)

Study


Neurodevelopment



development

multiparous), maternal prenatal

smoking (lower if smoking),

household poverty and child’s sex

(lower if male)

- Mental development scores were

significantly different among

maternal age, and maternal

prepregnancy BMI

Huizink et

al., 200371

Prospective

cohort study

A sample of 170

nulliparous women

were recruited through

pregnancy. Pregnancies

were singleton,

uncomplicated, good

baby health. Women

spoke fluent Dutch, did

not use drugs or

medication.

- Bayley Scales of

Infant Development,

1st edition at 3 and 8

months of age

- Assessed general

motor development

- Everyday Problem List

- Pregnancy Related Anxieties

Questionnaire-Revised

- Salivary cortisol

- Edinburgh Postnatal Depression

Scale

- Confounders: education,

professional level of women and

partner, tobacco and alcohol use,

biomedical risk factors during

pregnancy (cumulative score)

- Perinatal covariates: birth

weight, gestational age, delivery

complications (cumulative score)

- Postnatal covariate:

breastfeeding, psychological well-

being, perceived stress

- Mental development at 3 and 8

months significantly correlated.

Motor development at 3 and 8

months also significantly correlated

- A high amount of daily hassles

early in pregnancy, or a strong fear of

giving birth in late pregnancy was

associated with lower mental

development scores at 8 months

- A strong fear of giving birth mid-

pregnancy was associated with low

mental and motor development at 8

months

- High cortisol levels during late

pregnancy was related to low mental

development scores at 3 months and

low motor scores at both 3 and 8

months

Jacobson et

al., 199372

Prospective

cohort study

A sample of 382 Black

13-month-old infants

were recruited. Infants

had birth weight above

>1500 grams,

gestational age greater

than 32 weeks, no major

chromosomal anomalies

or neural tube defects or

multiple births.

- Bayley Scales of

Infant Development,

2nd edition at 6, 12

and 24 months of age

- Assessed general

motor development

- Alcohol and drug use (cocaine,

marijuana, opiates, depressants,

stimulants) during pregnancy

- Peabody Picture Vocabulary Test

- Home Observation for

Measurement of the Environment

(HOME Inventory)

- Beck Depression Inventory

- Control variables: maternal age,

education, marital status, welfare

status, parity, infant sex, smoking

- Maternal alcohol consumption

during pregnancy was associated with

lower mental development and

McCall index scores.

- Motor development was reduced

when maternal alcohol consumption

was reported at highest levels

(2oz/day during pregnancy; 4oz/day

at conception)

- Infants whose mother drank

0.5oz/day of alcohol were twice as

42

Author

(Year)

Study


Neurodevelopment



development

during pregnancy, number of

prenatal visits, quality of prenatal

visits

likely to score in the bottom 10th

percentile of mental development

scores

- Infants whose mother drank

2.0oz/day of alcohol were five times

as likely to score in the bottom 10th

percentile of motor development

scores

Janssen et

al., 201173

Prospective

cohort study


with gestational age <32

weeks were recruited.

- Bayley Scales of

Infant Development,

1st edition at 13

months of age

- Assessed general

motor development

- Gross Motor

Function

Classification System

(identify subgroup

with cerebral palsy)

- Infant factors: sex, gestational

age, birth weight, neonatal

convulsion, retinopathy of

prematurity, necrotizing

enterocolitis, interventricular

hemorrhage, periventricular

leukomalacia, chronic lung disease

- Growth variables: height, weight,

head circumference

- Parent factors: maternal

education

- Motor develop of preterm infants

from 6-24 months was unstable

- Motor development was influenced

by male sex, height, intraventricular

hemorrhage and motor quality

- The influence of maternal education

varied at different time points

43

Author

(Year)

Study


Neurodevelopment



development

Johnson et

al., 201274

Prospective

cohort study

A sample of 309

mother-infant dyads

were recruited. Mothers

were exposed to either

antidepressants or

antipsychotics, but not

antiepileptics. Mothers

also had no history of

substance abuse prior to

6 months of conception.

- Infant Neurological

International Battery

at 4-18 months of age

- Assessed general

motor development

- Habituation paradigm: infants’

fixation time on stimulus decrease

by 50% compared to previous

trials

- Structured clinical interview:

determine current and lifetime

psychiatric diagnoses


- Non-associated variables:

neurological test: gestational age,

delivery complications, birth

weight, sex, maternal education,

number of children at home,

bipolar/anxiety disorder, number

of mood episodes, number of

psychotic symptoms, duration of

disorder, number of

hospitalizations, leave of absence

due to mental illness, current

treatment status, previous therapy,

concomitant prenatal exposure to

anxiolytic and hypnotics

- Covariates significantly related to

Infant Neurological International

Battery score: infant age, maternal

age, marital status, lifetime history of

at least 1 depressive episode or

dysthymia, lifetime diagnosis of

psychotic disorder, severity index

- Maternal age was positively

associated with habituation, whereas

breastfeeding was associated with

habituation in fewer trial. Number of

months depressed during pregnancy

was also associated with longer

habituation times.

- Postnatal exposure via lactation to

antipsychotics associated with lower

neurological test scores.

Antidepressant exposure failed to

predict scores.

- Infants with antipsychotic exposure

had significantly lower neurological

score than antidepressant exposed or

unexposed infants. Unexposed infants

did not differ from antidepressant

exposed infants.

- No significant effects of prenatal

medication exposure on habituation

tasks were revealed

44

Author

(Year)

Study


Neurodevelopment



development

Julvez et

al., 200975

Prospective

cohort study

A subset of 420 children

from the Menorca

cohort study were

assessed.

- McCarthy Scales of

Children’s Ability

adapted in Spanish at

4 years of age

- Assessed general

motor development

- Current use of prescribed or

over-the-counter medications or

supplements (including folate,

vitamins, calcium, iron

supplements)

- California Preschool Social

Competence Scale

- Attention-deficit hyperactivity

disorder criteria from DSM-IV (by

two neuropsychologists)

- Additional covariates: parental

education, SES, marital status,

maternal health, obstetric history

(pregnancy complications, type of

delivery) parity, alcohol and

tobacco use during

pregnancy/child exposure to

smoke, paternal smoking

- Infant variables: Gestational age

and birth anthropometric

measurements

- Semi-quantitative food frequency

instrument: dietary intake during

pregnancy

- Folic acid supplementation was

associated with verbal, motor and

verbal executive functions, social

competence and inattention

symptoms when adjusting for SES,

education, parity, marital status,

smoking during pregnancy, calcium

and iron supplementation, sex,

duration of breastfeeding, child’s age,

season of neurological assessment

and area of residency

- Maternal iron and calcium

supplement use at the end of the first

trimester of pregnancy was not

associated with any

neurodevelopmental outcomes

- Social class, education, location,

parity, smoking during pregnancy

and duration of breastfeeding were

associated with folic acid

supplementation

Kanazawa

et al.,

201476

Prospective

cohort study

A sample of 37 preterm


Infants had gestational

ages of no later than 36

weeks and had no

congenital

malformations,

chromosomal

anomalies,

periventricular

hemorrhage, severe

respiratory failure, or

- Pediatric Evaluation

of Disability

Inventory at 18

months of age.

- Alberta Infant

Motor Scale at 18

months of age.

- Both assessed

general motor

development

- Muscle and subcutaneous

thickness: measured using real-

time ultrasound imaging

- Significant correlations between

Pediatric Evaluation of Disability

Inventory and subcutaneous fat

thickness. No correlation with

muscles thickness found.

- Motor delay group had significantly

lower subcutaneous fat thickness

values at 3 and 18 months of age, and

lower weight at 3 and 6 months of

age, and lower BMI at 3 months of

age.

- Using logistic regression only

45

Author

(Year)

Study


Neurodevelopment



development

necrotizing

enterocolitis.

subcutaneous fat thickness was a

significant predictor of motor delays

Kaplan-

Estrin et

al., 199977

Prospective

cohort study

A sample of 92

economically

disadvantaged, African

American, 26-month

old toddlers were

recruited.

- Bayley Scales of

Infant Development,

1st edition at 13 and

26 months at age

- Assessed general

motor development

- Alcohol and drug use protocol:

interviews at each prenatal visit

begin at 13 weeks’ gestation and at

13 months postpartum. Data

collected for opiates (heroin,

methadone, codeine), cocaine,

marijuana, depressants and

stimulants. Urine screen at 1st

prenatal visit.

- Three language development

measures: 1) Communication

Development Inventory – Words:

Short form, 2) the Noncanonical

Commands test, and 3) the Early

Language Milestone Scale

- Control variables: maternal age,

education, marital status, welfare

status, gravidity, parity, sex,

smoking during pregnancy, illicit

drug use, number of prenatal

visits, indicator of quality of

prenatal care

- Peabody Picture Vocabulary

Test-Revised

- HOME Inventory


- Current Maternal Drinking

- At 13 and 26 months of age,

maternal drinking associated with

lower mental and motor development

scores. At 13 months, maternal

drinking at conception was associated

with mental and motor development,

whereas drinking during pregnancy

was only associated with mental

development.

- Drinking during pregnancy was not

associated with language scores.

Drinking postpartum, however, was

related to language intelligibility

46

Author

(Year)

Study


Neurodevelopment



development

Kato et al.,

201678

Retrospective

cohort study

A sample of 104 very-

low-birth weight infants

were recruited.

- Kyoto Scale of

Psychological

Development at 3

years of age

- Assessed general

motor development

(postural-motor)

- Gestational age: <28 weeks or

>28 weeks

- Infant growth: appropriate-for-

gestational age, small-for-

gestational age, severely small-for-

gestational age

- Transfontanellar ultrasound

examinations for first 5 days

postpartum

- Brain magnetic resonance

imaging at discharge from NICU

- Electroencephalography (EEG)

- Other variables: Maternal

smoking and drinking, neonatal

diseases (respiratory distress

syndrome, infections, retinopathy

of prematurity, chronic lung

disease, intracranial hemorrhage,

periventricular leukomalacia,

necrotizing enterocolitis,

meconium disease

- Among infants >28 weeks’

gestation, no differences were

reported in developmental quotient

between severely small-for-

gestational age and appropriate-for-

gestational age. However, among

extremely premature infants,

differences in postural-motor

development were reported severely

small-for-gestational age and

appropriate-for-gestational age

- Gestation age, birth weight, birth

length and birth head circumference

were all significantly lower in infants

with delays in postural motor

development. Longer duration of

mechanical ventilation was also

associated with postural-motor delays

47

Author

(Year)

Study


Neurodevelopment



development

Larroque et

al., 199579

Prospective

cohort study

A sample of 155

mother-child dyads

were recruited. Mothers

were from the Roubaix,

France region and had

singleton pregnancies.


Children’s Abilities at

4.5 years of age

- Assessed general

motor development

- Alcohol consumption: prior to

pregnancy and first trimester

- Home Observation for the


Scale

- Covariates measured: child’s

health, sleep or feeding disorders,

problems at school, life events,

sociodemographic characteristics,

tobacco consumption during

pregnancy, birth weight

- Covariates included in the

model: birth order, maternal

education, maternal employment,

family status, score of family

stimulation, gender, age, and

examiner

- Crude analysis showed a significant

relationship between alcohol

consumption during pregnancy and

general cognitive index, verbal,

performance and quantitative scale

scores

- Scores on the memory or motor

scales were not related to alcohol

consumption during pregnancy

- Poor general cognitive index was

associated with decreased education,

no maternal occupation, single

family, higher birth order, low family

stimulation, and cigarette

consumption during pregnancy

- After controlling for confounders,

mean general cognitive index was

lower among children of heavy

drinking mothers compared to light

drinking mothers

Little et al.,

200280

Prospective

cohort study

A subset of 915 toddlers

were assessed from the

Avon Longitudinal

Study of Parents and

Children.

- Griffiths Scale of

Mental Development

at 18 months of age

- Assessed general

motor development

- Alcohol use during pregnancy

- Breastfeeding practices

- Alcohol exposure via breastmilk


postpartum smoking, marijuana

exposure, caffeine exposure, 32-

week food frequency, parity,

employment at 32 weeks’

gestation, housing situation,

marital status

- Locomotor development scores

were higher among white infants than

infants of other ethnicities

- No significant effect of alcohol

exposure via breastmilk on locomotor

development

48

Author

(Year)

Study


Neurodevelopment



development

Mazer et

al., 201081

Prospective

cohort study

A sample of 117

children with congenital

anomalies were

enrolled.

- Bayley Scales of

Infant Development,

1st edition in Dutch at

6, 12 and 24 months

of age

> Assessed general

motor development

- Movement

Assessment Battery

for Children at age 5

years

> Assesse general

motor development

- Demographic and medical

information: ethnicity, SES, type

of congenital anomalies, total

number of major and minor

anomalies, total days spent in

hospital in their first 6 months,

number of medical appliances at

discharge, number of surgical

interventions and number of

additional medical problems in the

first 24 months

- Revised Amsterdam Children’s

Intelligence Test- short version

- Predictors of IQ at 5 years:

- 6 months: Protective: High SES,

mental development on Bayley//Risk:

Non-Dutch, number of congenital

anomalies

- 12 months: Protective: High

SES, mental development on

Bayley//Risk: Non-Dutch, number of

congenital anomalies

- 24 months: Protective: mental

development on Bayley//Risk:

number of congenital anomalies

- Predictors of motor development at

5 years:

- 6 months: Protective:

psychomotor development on

Bayley//Risk: Non-Dutch

- 9 months: Protective:

psychomotor development on Bayley

- 12 months: psychomotor

development on Bayley//Risk:

medium SES

Messinger

et al.,

200482

Prospective

cohort study

A subset of 1227

mother-children dyads


Maternal Lifestyle

Study. Mothers were 18

years or older, without

psychiatric

disorders/developmental

delays or language

barriers. Infants were

inborn, likely to

survive, singleton,

gestational age <43

weeks.

- Bayley Scales of

Infant Development,

2nd edition at 12, 24,

36 months of age.

- Assessed general

motor development

- Maternal Interview of Substance

Use/Meconium metabolite

benzoylecgonine

>Main exposure=cocaine and

opiates

> Alcohol, tobacco and

marijuana included as covariates

- Additional covariates: maternal

education, SES (Hollingshead

Index of Social Position Score),

poverty status, maternal care vs

other care



- Significant differences between

infants exposed to cocaine and not

exposed to cocaine were reported for

mental development at 1 and 3 years

of age and overall mental

development. No differences were

observed for motor development.

- Significant differences between

infants exposed to opiates and not

exposed to opiates were reported for

mental development at 1 year, motor

development at 2 and 3 years, overall

motor development, and behavioral

ratings at 2 years of age.

49

Author

(Year)

Study


Neurodevelopment



development

(HOME) Inventory


Test-Revised

- Brief Symptom Inventory from

the Global Severity Index of

psychological symptoms

-Behavioral Rating Scale

- After controlling for covariates,

neither cocaine nor opiates were

associated with mental development

scores



associated with psychomotor

development scores



associated with behavioral rating

scores

- Low birth weight was associated

with low mental, motor and

behaviour scores

- Higher quality of caregiving was

associated with higher mental and

motor development scores

- Higher HOME scores were

associated with higher psychomotor

and behavior scores

- Consistent presence of the mother in

the household was associated with

higher mental and psychomotor

scores

Mellins et

al., 199483

Cross-

sectional

study


were recruited. Among

those recruited, 24

infants were HIV-

positive, 30

seroreverters, and 23

non-infected infants

born to mothers without

HIV.

- Bayley Scales of

Infant Development,

1st edition at 4-30

months of age

- Assessed general

motor development

- HIV-status

- Prenatal drug exposure

- Infants exposed to HIV and prenatal

drugs had an increased risk of poor

mental and motor development

compared to infants with either HIV

infections or prenatal drug exposure

- Drug exposure and neurological

dysfunction were risk factors for

mental development using multiple

regression

- Neurological dysfunction was a

significant predictor of psychomotor

development

50

Author

(Year)

Study


Neurodevelopment



development

- No significant effect on mental or

motor development and sex or

ethnicity

Mendez et

al., 200884

Prospective

birth cohort

A sample of 392 full-

term children and their

mothers were enrolled.


Children’s Abilities

test at 4 years of age.

- Assessed general

motor development

- Seafood consumption: semi-

quantitative, interviewer-

administered questionnaire.

>interested in DHA content

- Covariates: maternal education,

parity, sex, birth weight, weeks’

gestation, breast-feeding duration,

child age at testing, examiner

- Among children breastfed for <6

months, maternal fish intakes of >2-3

times/week remained associated with

significantly higher mean scores

across all subscales

- Maternal intakes of other types of

seafood during pregnancy were

associated with lower general

cognitive, perceptual-performance,

verbal and numeric scores at 4 years

of age

- Child intake of fish and other types

of seafood was not associated with

test scores

Miller-

Loncar et

al., 200485

Prospective

cohort study

A subset of 392 cocaine

exposed and 776

unexposed infants from

the Maternal Lifestyle

Study were assessed.

- NICU Network

Neurobehavioral

Scale (NNNS) at 1

month of age

> Assessed general

motor development

(combined composite

score)

- Posture and Fine

Motor Assessment of

Infants (PFMAI) at 4

months of age

> Assessed

postural and fine

motor development

(combined into

composite score)

- Bayley Scales of

- Maternal Inventory of Substance

Abuse (timing and amount of

cocaine, alcohol, nicotine, and

marijuana used during pregnancy

- Hollingshead Index of Social

Position

- Covariates: SES, birth weight,

race, study site

- Prenatal cocaine exposure was

significantly associated with poorer

motor skills.

- Prenatal cocaine exposure interacted

with age, where infants exposed to

cocaine displayed a faster rate of

increase in motor skills than the

comparison group

- Study site, birth weight and heavy

tobacco use was also associated with

motor development

- Heavy prenatal exposure to cocaine

was associated with poorer motor

scores compared to unexposed

infants. There was not a significant

difference based on level of exposure

for change over time, however.

51

Author

(Year)

Study


Neurodevelopment



development

Infant Development,

2nd edition at 12

months of age

> Assessed general

motor development

- Peabody

Developmental Motor

Scales at 18 months

of age

> Assessed general

motor development

(combined into

composite score)

Minguez-

Milio et al.,

201186

Prospective

cohort study

A sample of 138

extremely-low-birth

weight infants were

recruited. Of those

recruited, 73 were born

via C-section and 65

were born vaginally.



61.18 months of age

- Assessed general

motor development

- Clinical records: maternal age,

parity, previous miscarriages,

previous history of preterm

delivery, gestational age,

- Pregnancy features: the presence

of threatened abortion, urine

infections, maternal anemia, pre-

eclampsia, intrauterine growth

restrictions, hydramnios,

oligoamnios, premature rupture of

membranes, cervical

incompetence

- Delivery: presentation, route of

delivery

- Newborns: birth weight, Apgar

scores, gestational age, sex,

umbilical cord blood gases, type of

reanimation used

- Neonatal morbidity: respiratory

distress syndrome, periventricular

hemorrhage, bronchopulmonary

dysplasia, periventricular

- 29.1% of children exhibited

developmental delays. Among those

children 27% exhibited motor delays.

- Route of delivery and sex were not

found to be associated with

development scores

52

Author

(Year)

Study


Neurodevelopment



development

leukomalacia, retinopathy of

prematurity, sepsis, seizures,


pneumothorax, pneumonia, patent

ductus arteriosus, apnea,

meningitis, transitory RDS,

hemodynamic shock

- Procedures carried out on

newborn

Mulligan et

al., 199887

Prospective

cohort study

A sample of 48 full-

term infants were

recruited from an

ongoing longitudinal

study. Infants were free

of chronic disease that

may interfere with

growth.

- Bayley Scales of

Infant Development,

1st edition at 6, 9 and

12 months of age

- Assessed general

motor development

- Children’s Activity Rating Scale

- Centre Activity Evaluation:

caregiver ratio, whether infants

spent time in gross motor room,

level that the infants were

encouraged to interact with

caregivers and environment, use of

infant equipment, number of

square feet per infant

- Percent body fat: dual energy x-

ray absorptiometry (DXA)

- Child’s weight

- At 6 months of age, psychomotor

development was not associated with

any center characteristics

- At 9 months of age, psychomotor

development was lower among

infants in centers with

infant:caregiver ratios of 5:1

compared to ratios of 3:1 or 4:1

- At 12 months of age, the use of

infant equipment was not associated

with motor development

Nakajima

et al.,

200688

Prospective

cohort study

A sample of 134

mother-child dyads

were recruited into the

Hokkaido Study on

Environment and

Children’s Health). All

subjects were native

Japanese and residents

of Sapporo and

surrounding areas.

- Bayley Scales of

Infants Development,

2nd edition at 6

months of age

- Assessed general

motor development

- Blood sample during second

trimester

- Questionnaire of home

environment

- Polychlorinated dibenzo-p-dioxin

(PCDD) isomer 1,2,3,4,6,7,8-

HpCDD, total PCDDs and total

PCDDs/PCDFs (polychlorinated

dibenzofurans) were negatively

associated with mental development

- PCDD isomers 1,2,3,7,8,9-HxCDD,

1,2,3,4,6,7,8-HpCDD, 2,3,7,8-TCDF,

1,2,3,7,8-PeCDF, and PCDF isomer

1,2,3,6,7,8-HxCDF were all

negatively associated with


***NOTE: This is an analysis of

polychlorinated biphenyls (PCBs)

and dioxins, persistent environmental

pollutants***

53

Author

(Year)

Study


Neurodevelopment



development

Nash et al.,

201189

Retrospective

cohort study


low-brithweight preterm


Infants were excluded if

they had a serious

congenital anomaly or

depression at birth, were

small-for-gestational

age, or died during

initial hospitalization.

- Bayley Scales of

Infant Development,

3rd edition at 18-24

months of age

- Assessed general

motor development

(composite score)

- Infant characteristics: gestational

age, sex, multiple birth status,

inborn/outborn status, necrotizing

enterocolitis, patent ductus

arteriosus, nosocomial infection,

intraventricular hemorrhage,

chronic lung disease,

dexamethasone use

- Growth assessment: weight,

length, head circumference

- Males and females had similar

cognitive and motor composite

scores, however, males had lower

language scores than females

- Using WHO growth standards,

children with a decelerated pattern of

weight gain had lower cognitive,

language and motor scores compared

to infants with sustained weight gain

- No association was found using

CDC reference growth charts

Nelson et

al., 200490

Prospective

cohort study

A sample of 143 2-year

old and 274 4-year old

children were enrolled.

- Bayley Scales of

Infant Development,


of age

>Assessed general

motor development

- Peabody

Developmental Motor

Scales at 4 years of

age

> Assessed fine

and gross motor

- Cocaine, marijuana, tobacco,

alcohol exposure


Test-Revised

- Brief Symptom Inventory/Global

severity Index

- Maternal characteristics: race,

age, SES, gravida, parity, number

of prenatal care visits

- Infant Measures: birth outcomes,

Apgar scores, Hobel Neonatal

Risk Index

- Hematologic assessment:

hemoglobin, mean corpuscular

volume, transferrin saturation,

serum ferritin, lead, iron status

- Environmental measures: Home

Observation of the Environment

(HOME) Inventory

Neurodevelopment: Wechsler

Preschool and Primary Scales of

Intelligence

- Correlations with motor

development:

- 2-year psychomotor: ethnicity,

parity, maternal education, sex

- 4-year gross motor: parity,

maternal IQ (PPVT-R), birth weight,

head circumference, Hobel risk score,

gestational age

- 4-year fine motor: parity,

maternal education, sex, nonmaternal

care

- Full Scale IQ was predicted by iron

deficiency anemia and lead levels

- Verbal IQ was predicted by HOME

scores

- Performance IQ was predicted by

maternal IQ, cocaine exposure and

lead

Ohman et

al., 200991

Prospective

cohort study


with congenital

muscular torticollis and

40 healthy control

- Alberta Infant

Motor Scales (AIMS)

at 2, 6 or 10 months

of age

- Physiotherapist treatment

- Infants gestation age, weight and

length at birth

- Sleep and awake position

- At 2 and 6 months of infants with

congenital muscular torticollis scores

significantly lower on motor scores

than the healthy control infants

54

Author

(Year)

Study


Neurodevelopment



development

infants were enrolled.

Infants were aged either

2, 6 or 10 months of

age, were born >37

weeks’ gestation and

had no suspected

syndromes or medical

conditions.

- Assessed general

motor development

- Infants who spent at least 3 three

times daily prone when awake had

significantly higher AIMS scores

then those who spent less time in

prone at 2, 6 and 10 months of age

- Gestational age, sex, birth weight,

birth length, and plagiocephaly had

no significant effect on AIMS scores

Polanska et

al., 201592

Prospective

cohort study

A subset of 538 mother-

child dyads from the

Polish Mother and

Child Cohort Study

were assessed.

Pregnancies were

singleton, unassisted

conception,

uncomplicated and

mother had no chronic

diseases.

- Bayley Scales of

Infant and Toddler

Development at 12


- Assessed general

motor development

- Smoking history via interview

and salivary cotinine levels

- Alcohol consumption via

questionnaire

- Leisure-time physical activity at

three point during pregnancy and

metabolic equivalent value was

assigned to each activity

- Pre-pregnancy BMI

- Folic acid supplementation

before and during pregnancy

- Confounding variables: sex,

parental age, education, SES,

marital status, major pregnancy

complications

(diabetes/hypertension/intrahepatic

cholestasis), type of delivery,

gestational age, biometric

indicators of birth, breastfeeding,

number of siblings, day care

attendance

- Cotinine levels were negatively

associated with motor and cognitive

development at 24 months of age in

adjusted models

- Children of underweight women

had lower language and cognitive

scores at 1 year of age and lower

motor scores at 2 years of age

compared to children of normal

weight women

- Recommended leisure activity in

the first, second and third trimesters

was associated with higher language

development at 2 years

- Prenatal exposure to tobacco was

associated with low motor

development at 1 and 2 years of age,

underweight pre-pregnancy was

associated with language abilities at 1

year of age and recommended level

of physical activity had a positive

impact on language development at 2

years in the final multivariable model

with inclusion of all lifestyle factors

and confounders

Ratliff-

Schaub et

Prospective

cohort study


from the Collaborative

- Bayley Scales of

Infant Development,

- Sleep position

- Parenting Stress Index subscale

- Race and alcohol consumption

during pregnancy were associated

55

Author

(Year)

Study


Neurodevelopment



development

al., 200193 Home Infant

Monitoring Evaluation.

Infants were <1750

grams and < 34 weeks’

gestation.

2nd edition at 44, 56

and 92 weeks of age

- Assessed general

motor development

- Confounders: race, marital status,

maternal age, education, smoking

or alcohol consumption during

pregnancy, parity, family got

along, days in hospital,

methylxanthine use, sex, birth

weight, head circumference,

supplemental 02 use

with sleep positive in bivariate

analysis

- Significant difference between

motor skill item and sleep position:

holds head in midline position,

maintains head at 45o and lowers with

control, maintains head at 90o and

lowers with control

- Psychomotor and mental

development scores did not differ

between prone and supine sleepers in

either the unadjusted or adjusted

analyses at 56 or 92 weeks of age

Ravenscroft

et al.,

200794

Cross-

sectional

study

A sample of 412

Canadian infants born at

term, weighing >2500

grams and no history of

prenatal, perinatal or

postnatal medical

complications or

maternal complication

were enrolled.

- Harris Infant

Neuromotor Test

(HINT) at 3-12

months of age

- Assessed general

motor development

***NOTE: lower

score indicates better

development***

- Maternal education level

- Infant age

- Bivariate analysis: Highly negative

correlation between infant age and

HINT scores (indicates improving

development with age), weak positive

relationship between maternal

education and HINT score

- No effect of maternal age and HINT

scores when controlling for infant age

Richardson

et al.,

200895

Prospective

cohort study

A sample of 320 women

were enrolled into the

study.

- Bayley Scales of

Infant Development,

2nd edition at 1 year

of age

- Assessed general

motor development

- Use of cocaine, crack, tobacco,

marijuana, alcohol or other illicit

substances prior to pregnancy or

during first trimester

- Infant: length, weight, head

circumference, age, growth at 1-

year postpartum, medical history

- Infant Behaviour Record

- Mothers: substance use,

demographic characteristics, social

support, household composition,

psychological characteristics

- Centre for Epidemiological

- Bivariate analyses: Infants exposed

to cocaine in the first trimester has

lower gestational age, lower birth

weight, more likely to be born

prematurely, have lower psychomotor

score and rated as more

fussy/difficult and unadaptable than

were the infants were not exposed.

- There were no effect of prenatal

cocaine/crack use on weight, height

or head circumference at 1 year

- Significant predictors of growth

were: age, male, maternal height.

56

Author

(Year)

Study


Neurodevelopment



development

Studies – Depression Scale

-Spielberger State-Trait Anxiety

Inventory

- Bates Infant Characteristics

Questionnaire

- PROCESS scale: assess home

environment

Decreased growth predictors were:

maternal depression, prenatal tobacco

and alcohol use.

- There were no effect of prenatal

cocaine/crack use on mental

development

- Significant predictors of mental

development were: higher PROCESS

scores, Caucasian, examiner.

Predictors of lower scores were: older

age, more children in the household,

presence of a male in the household,

prenatal alcohol use

- Second trimester cocaine/crack use

was a significant predictor of

psychomotor development. Lower

score was predicted by older age at

assessment, prenatal alcohol

exposure, more children in the

household

- Cocaine exposure during 1st and 2nd

trimester were predictors of

unadaptable factor of the Bates ICQ

Scale. Moreover, cocaine use during

the 2nd and 3rd trimester predicted

increased fussiness/difficultness

- Additional predictors of difficult or

unadaptable temperament scores

were: younger age, lower maternal

education, more hospitalization,

maternal depression, more children in

the household, third trimester

marijuana exposure, and higher levels

of current maternal substance use

- Less difficult temperament was

predicted by the presence of a male in

the house, and more developmental

57

Author

(Year)

Study


Neurodevelopment



development

stimulation in the home

Ronfani et

al., 201596

Prospective

cohort study

A subset of 900 women


PHIME project (Public

health impact of long-

term, low-level, mixed

element exposure in

susceptible population

strata).

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Assessed general

motor development

- Standard Progressive Matrices

(SPM): maternal IQ

- Appraisal of Indicators through

Research and Evaluation:

assessment of home environment

- Socioeconomic Status Index

- Potential explanatory variables:

sex, birth weight, gestational age,

maternal age at delivery, BMI

before pregnancy, maternal

mercury exposure (hair and

venous blood samples), house

surface, mother living with

partner, other children living in the

house, maternal smoke, alcohol

intake during pregnancy, dental

visits, dental works, exclusivity of

breastfeeding at 4 months, daycare

attendance

- Only “promotion of autonomy” on

the AIRE scale was independently

associated with cognitive score

- Mediation analysis showed a

direct effect of SES on cognitive

development and a mediation effect

on the promotion of autonomy

- Multivariable analysis revealed

maternal IQ and promotion of

autonomy are independently related

to language development


direct effect of maternal IQ on

language development and a

mediation effect of SES on this

relation

- A direct effect of SES and a

mediation by promotion of autonomy

was also observed

- Multivariable analysis revealed

maternal IQ and promotion of

autonomy are independently related

to motor development


direct effect of maternal IQ on motor

development and this relation is

mediated by promotion of autonomy

58

Author

(Year)

Study


Neurodevelopment



development

Sansavini

et al.,

199697

Prospective

cohort study

A sample of 250 healthy

Italian preterm infants

were enrolled. An

additional 35 healthy

full-term infants were

enrolled and matched

for age, sex, and

socioeconomic status.

- Brunet-Lezine Test

(Italian) administered

at 6, 12 and 24

months postpartum

- Assessed general

motor development

- Standord-Binet Intelligence test

- Medical information: Apgar

score, neonatal complications

- Biological risks: birth weight,

intra-uterine growth retardation,

sec

- Social risks: maternal and

paternal education

- Preterms present delays in

developmental quotients, motor, eye-

hand coordination, language and

social behaviour development

- Biological risks were associated

with global and specific development

(except language) at 6,12 and 24

months of age. Moreover, intra-

uterine growth retardation was

associated to global development at 5

years of age.

- Paternal education was related to

cognitive development at 12 months,

linguistic and global development at

24 months and global development at

4 and 5 years

- Maternal education was related to

cognitive and global development at

12 months, and linguistic

development at 24 months

Santos &

Costa,

201598

Cross-

sectional

study

A sample of 109

Portuguese families

were enrolled. The

infants were aged 6-22

months and free from

existing disease. Parents

were literate.

- Scale of

Psychomotor

Development in Early

Childhood

- Sociodemographic data: age,

gender, marital status, years of

education, professional status,

physical and psychological

diseases, medical or psychological

treatment, number of pregnancies,

number of miscarriages, number

of children, age of children,

children’s physical and

psychological diseases

- Clinical data: pregnancy

planning, prenatal care, risk

pregnancy, gestational age, type of

delivery, type of anesthesia, Apgar

score, weight, height, head

circumference, reanimation, health

problems at birth, current sleep

- No significant correlation between

maternal or paternal nicotine

dependence and cigarette smoking,

and the postural, visual-motor,

language, social and overall child

development

- Negative correlation between

paternal nicotine dependence,

smoking and morning smoking and

the child’s language development

quotient

- Univariate analysis showed that

children of mothers without nicotine

dependence had higher mean visual-

motor development and language

quotients than child of dependent

mothers. There was no difference

59

Author

(Year)

Study


Neurodevelopment



development

pattern, type of feeding

- Fagerstrom Test for Nicotine

Dependence

between children of mothers or

fathers with or without dependence

on overall child development.

Scher et al.,

200899

Prospective

cohort study

A convenience sample

of 142 infants were

assessed. Infants were

participating in the

Training and Outcomes

for Early Identification

of Infants with

Neuromotor Delays.

Infants were born at

term (>37 weeks’

gestation), weighed

>2500 grams, and had

no postnatal infant

health problems or

congenital anomalies.

- Harris Infant

Neuromotor Test

(HINT) at 4-6 and 10

12 months of age

- Assessed general

motor development

***NOTE: lower


development***

- Alberta Infant

Motor Scale 4-6 and

10 12 months of age

- Assessed general

motor development

- Ages and Stages

Questionnaire at 4-6

and 10 12 months of

age

- Assessed fine

and gross motor

development

- Infant Sleep Questionnaire

- HINT scores were not associated

with scores from the Infant Sleep

Questionnaire

- Parental perception of child’s sleep

difficulty was associated with child

neurodevelopment at 10-12 months

of age, but not at 4-6 months of age

- Severity of sleep difficulties

significantly decreased with age in

the “no-risk group” and the “low risk

group”, but not in the “high risk

group”

- In the low-risk group, sleep

difficulties decreased with age,

whereas in the high-risk group, sleep

disruption increased over time

Schuler et

al., 2003100

Randomized

cohort study

A sample of 108 low-

income, inner-city,

drug-exposed children

were recruited.

- Bayley Scales of

Infant Development

at 6, 12 and 18

months of age

- Assessed general

motor development

- Home visit: visit date, time in the

home, who had custody of the

study child, if the mother or child

were in any programs, date of

child’s next physician visit,

whether the family was moving

soon

- Home intervention: based on the

“Infant Health and Development

Program”

- Maternal component: enhance

- No correlations were found between

ongoing alcohol or marijuana use and

mental or psychomotor development

- Mental development was higher

among infants in the intervention

group compared to the control group

- Motor development was higher

among infants in the intervention

group compared to the control group

60

Author

(Year)

Study


Neurodevelopment



development

mothers’ ability to manage self-

identified problems using existing

services and family and social

support

- Child component: to promote

infant development using a

program of games and activities

- Drug exposure: use of cigarettes,

alcohol, heroin, cocaine,

marijuana, amphetamines,

barbiturates, tranquilizers,

hallucinogens during pregnancy

Serenius et

al., 2013101

Prospective

cohort study

A sample of 491

extremely preterm

infants and 701 control

infants were enrolled.

- Bayley Scales of

Infant Development,

3rd edition at 2.5 years

of age

- Assessed general

motor development

- Parental education

- Child health and development

- Maternal age, parity and smoking

status

- Among preterm infants, language

and motor

developmental scores increase with

increased gestation age

- Language scores were lower among

preterm boys, but no sex differences

were observed for cognitive or motor

development

- No differences on developmental

scores were observe between

singleton vs. multiple birth or history

of congenital malformations

- Moderate or severe disabilities

decreased with advancing gestational

age and were more prevalent in boys

Sherlock et

al., 2008102

Retrospective

cohort study

A subset of 6664

families with children

of 2 years of age from

the Canadian National

Longitudinal Survey on

Children and Youth-

Cycle 3 were assessed.

- Motor and Social

Development Scale at

2 years of age

- Assessed general

motor development

- Demographic, parent and family

environment characteristics

- Covariates: duration of maternity

leave, sex, SES (education,

prestige of occupation, household

income) breastfeeding, number of

children in the household, preterm

birth

- Maternity leave duration as a

continuous variable in months was

associated with increased risk of

impaired performance on the Motor

Social Development scale (MSD)

- Boys scored lower on the MSD

- Higher SES and decreased number

of children in the household were

protective factors for development

- Preterm birth and breastfeeding

61

Author

(Year)

Study


Neurodevelopment



development

were not found to be associated with

the MSD

Singer et

al.,2012103

Prospective

cohort study

A sample of 96 mother-

child dyads were

enrolled into the study.

Dyads were not HIV

positive, no sign of

maternal

moderate/severe mental

retardation, no

psychiatric/medical

illness or child medical

illnesses.

- Alberta Infant

Motor Scale (AIMS)

at 4 months of age

> Assessed general

motor development

- Bayley Scales of

Infant Development,

1st edition at 4 months

of age

> Assessed general

motor development

- Behavioural Rating

Scale at 4 months of

age

> Assessed quality

of motor movements

- MDMA exposure via interview

- Prenatal levels of drug exposure:

adapted from the Maternal

Postpartum Interview

> measures tobacco, alcohol,

marijuana, MDMA, heroin,

ketamine, crack, cocaine,

benzodiazepine, LSD,

hallucinogenic mushrooms

- Drug Abuse Screening Test

- Brief Symptom Inventory

- Covariates: maternal age, marital

status, ethnicity, education,

household income, fetal growth

measurements

- Wechsler Abbreviated Scales of

Intelligence

- NICU Network

Neurobehavioural Scale (NNNS)

- Among those using MDMA during

pregnancy, the mean number of

tablets ingested per week was 3.2

- No significant differences by group

on the Bayley mental or the

attention/arousal factor of the

Behavioural Rating Scale between

MDMA exposed infants and

unexposed infants

- Difference existed between groups

on the Behavioral Rating Scale Motor

Quality Scale, with MDMA-exposed

infants demonstrating significantly

poorer motor quality

- MDMA infants were rated as less

coordinated and more likely to have

slower and delayed movements

- There was a dose-response effect,

with higher average MDMA use over

pregnancy predicting poorer motor

quality

- At 4 months, AIMS scores were

lower among infants exposed to

MDMA compared to the unexposed

controls

- Higher alcohol exposure also

predicted poorer motor quality at 4

months

- Higher marijuana exposure

predicted poorer attention and poorer

regulation on the NNNS at one month

Singer et

al., 2012104

Prospective

cohort study


child dyads were

- Bayley Scales of

Infant Development,



- Higher amounts of MDMA

exposure predicted poorer mental and

62

Author

(Year)

Study


Neurodevelopment



development


Dyads were not HIV


maternal


retardation, no

psychiatric/medical


illnesses.

1st edition at 12

months of age

- Assessed general

motor development



age

> Assessed quality

of motor movements













measurements


Intelligence

- Child Domain Scale of Parenting

Stress Index

- Home Observation of the

Environment

- Preschool Language Scale

motor outcomes and assessors’

ratings of poorer motor quality at 12

months of age

- MDMA exposure was unrelated to

language and emotional-regulation

outcomes

- Lighter MDMA-exposed infants

were equivalent to unexposed infants

on all outcomes

- The Home Observation of the

Environment was related to higher

mental development scores and better

emotional regulation, orientation, and

language scores

- Boys had lower mental

development and emotional

regulation scores

- Higher alcohol exposure predicted

better orientation and expressive

language

- Higher crack-cocaine exposure

predicted lower expressive language

scores

Singer et

al., 2016105

Prospective

cohort study


child dyads were


Dyads were not HIV


maternal


retardation, no

psychiatric/medical


illnesses.

- Bayley Scales of

Infant Development,

3rd edition at 24

months of age

> Assessed general

motor development



age

> Assessed quality

of motor movements















- There is a significant effect of the

level of MDMA exposure on

psychomotor development over time

when adjusting for sex, test age,

parity, amount of prenatal cocaine

exposure

- There was no significant effect on

mental development scores and

MDMA exposure after adjusting for

child test age, HOME score at 12

months, sex

- There was a significant effect of

MDMA exposure on Behavioural

Rating Scale motor quality, with

63

Author

(Year)

Study


Neurodevelopment



development

measurements


Intelligence

- Child Domain Scale of Parenting

Stress Index


Environment

- Preschool Language Scale

heavier MDMA exposed children

being associated with poorer motor

quality than lighter or non-exposed

children

- Heavier MDMA-exposed infants

were perceived as having poorer

attentional skills than lighter exposed

infants

- Boys performed better than girls at

baseline on mental and motor scores,

however, there were significant

gender by age interactions that

resulted in boys performing worse

than girls as they got older

- Higher quality of the home

environment was also a predictor of a

higher mental development score and

better emotional regulation and motor

quality over time as rated by

examiners

Singer et

al., 1997106

Prospective

cohort study

Three groups of infants

(122 with

bronchopulmonary

dysplasia, 84 very-low-

birth weight without

bronchopulmonary

dysplasia, and 123 full-

term) were followed

longitudinally.

- Bayley Scales of

Infant Development,

1st edition at 8, 12, 24


- Assessed general

motor development

- Hospital chart review: gestational

age, birth weight, length, head

circumference, Apgar scores,

presence/absence of respiratory

distress syndrome,

bronchopulmonary distress

syndrome, patent ductus

arteriosus, necrotizing

enterocolitis, retinopathy of

prematurity, abnormal hearing test

results, number of days on

ventilator support, number of days

on supplemental oxygen, peak

bilirubin levels, septicemia,

neurologic risk score

- Cranial ultrasounds

- Infants with bronchopulmonary

dysplasia (BPD) achieved standard

scores significantly lower than very-

low-birth weight and term infants

- After controlling for social and

medical risk variables, BPD had

significant independent effects,

predicting poorer motor outcome

- Poorer mental developmental

outcome at 3 years was predicted by

minority race, lower social class,

lower birth weight and neurologic

risk score

- BPD independently accountant for a

12-point decrease in motor scores at 3

years, whereas neurologic risk

yielded an additional 14-point

64

Author

(Year)

Study


Neurodevelopment



development

decrement

- Neurologic risk accounted for a 10-

point decrement on mental

development scores

- Cognitive outcomes were

significantly associate with social

class within all risk groups

- there was no impact of social class

on motor development

Singer et

al., 1994107

Prospective

cohort study

A sample of 41cocaine-

exposed and 41 non-

exposed infants were

recruited.

- Bayley Scales of

Infant Development,

1st edition at 16-18

months of age

- Assessed general

motor development

- Hospital chart review: gestational

age, birth weight, length, head

circumference, Apgar scores,

presence/absence of respiratory

distress syndrome,

bronchopulmonary distress

syndrome, patent ductus

arteriosus, necrotizing

enterocolitis, retinopathy of

prematurity, abnormal hearing test

results, number of days on

ventilator support, number of days

on supplemental oxygen, peak

bilirubin levels, septicemia,

neurologic risk score

- Cranial ultrasounds: assessed for

intraventricular hemorrhage

- Cocaine-exposed infants has a

significantly increased incidence of

intraventricular hemorrhage than

non-exposed infants

- Cocaine-exposed infants performed

more poorly in cognitive and motor

skills when means scores were

compared

- When the incidence of

developmental delay was compared,

there was a significantly higher

incidence of disability in both mental

and motor domains in the cocaine-

exposed group

-Neither mental nor motor scores

were significantly different for

children placed outside the home

versus those who remained in the

care of their biological mothers

Slining et

al., 2010108

Prospective

cohort study

A subset of 217 mother-

infant dyads from the

Infant Care, Feeding

and Risk of Obesity

Study.

- Bayley Scales of

Infant Development,

2nd edition at 3, 6, 9,

12 and 18 months of

age

- Assessed general

motor development

- Infant anthropometric

measurements: weight, skin-fold

thicknesses (subscapular, triceps

and abdominal)

- Maternal height and weight

- Potential confounders: child sex,

age, maternal age, weight status

and education

- Male infants had significantly

higher weight-for-length z-scores

than female infants at 6 months only

- No significant sex differences in

motor development at any point

- Overweight infants were

approximately twice as likely as non-

overweight infants to have low

psychomotor scores

65

Author

(Year)

Study


Neurodevelopment



development

- Infants with high-subcutaneous fat

were more than twice as likely as

infants without high subcutaneous fat

to have a low psychomotor score

Smith et

al., 2000109

Prospective

cohort study


vertically infected with

HIV-1 were enrolled

- Bayley Scales of

Infant Development,

1st edition at 4, 9, 12,

15, 18, 24 and 30

months of age

- Infants had peripheral blood

specimens collected at <2 days of

life, < 7 days of life, and 1, 2 4, 6,

9, 12, 15 and 18 months of age and

every 6 months thereafter

- Interview: maternal education,

primary language, maternal drug

use, medical history, medical

regimens, presence of illness

- Prenatal use of illicit drugs

(opiates, cocaine, other injectables

and/or methadone): assessed via

urine toxicology and/or self-report

- Significant differences in

developmental scores between early

and late HIV infected were reported

- At 24 months, both motor and

mental scores among those early

infected were significantly lower than

those with late infections

- Both motor and mental scores

declined with age more rapidly in

early infected infants compared to

late infected infants

Stanton et

al., 1991110

Prospective

cohort study

A sample of 476 girls

and 510 boys were

enrolled at birth.

- McCarthy Motor

Scale at 5 years of

age

- Assessed general

motor development

- Perinatal complications index:

sum of the number of perinatal

complications experienced

- Health Index: sum of the number

of adverse health

exposure/conditions experienced

- Family Adversity Index: sum of

sociodemographic and family risks

- Child-rearing Index: measure of

child-rearing attitudes and

practices, and preschool

experiences

- Stanford-Binet Intelligence Scale

- Reynell Receptive and

Expressive Language Scales

- Adverse child-rearing practices

were associated with a relatively

higher level of perinatal complication

and a higher level of family adversity

- For boys, there was also a

significant association between an

adverse family background and a

poor level of health

- Effects of four indices of adversity

GIRLS:

IQ: Family background, child

rearing practices and child health

were predictive of IQ

Receptive Language: Predictors

were family background and child

rearing

Expressive Language: Predictors

were Family background and child

rearing

Motor Ability: Predictors were

66

Author

(Year)

Study


Neurodevelopment



development

Family background, child rearing and

child health

- Effects of four indices of adversity

BOYS:

IQ: Predictors were perinatal

complications, family background,

child rearing and child health

Receptive language: Predictors

were perinatal complications, family

background and child rearing

Expressive language: Predictors

were family background

Motor ability: Predictors were

family background, child rearing and

child health

Swanson et

al., 1999111

Prospective

cohort study

A sample of 120

cocaine-exposed and

186 non-exposed infants

were enrolled.

- Movement

Assessment of Infants

(MAI) at 4 months of

age

> Assessed tone,

primitive reflexes,

automatic reactions,

volitional movements

- Maternal history of drug use:

Cocaine, crack, alcohol, tobacco

and marijuana before and during

pregnancy (self-report and hair

sample analysis – only for

cocaine)

- Significant difference were

observed in adjusted and unadjusted

models for Movement Assessment of

Infants total risk score between

cocaine-exposed and unexposed

infants


observed in only unadjusted models

for Movement Assessment of Infants

Primitive Reflexes and Volitional

Movement score between cocaine-

exposed and unexposed infants


observed in adjusted and unadjusted

models for Movement Assessment of

Infants total risk score and Volitional

Movement scores between cocaine-

exposure throughout pregnancy,

cocaine-exposure in first or second

trimester and unexposed

Significant differences were observed

in only unadjusted models for

67

Author

(Year)

Study


Neurodevelopment



development

Movement Assessment of Infants

Primitive Reflex scores between

cocaine-exposure throughout

pregnancy, cocaine-exposure in first

or second trimester and unexposed

Tauman et

al., 2015112

Prospective

cohort study

A sample of 74 women-

infant dyads were

recruited. Women were

in the third trimester of

a singleton,

uncomplicated

pregnancy.

- Spontaneous general

movement assessment

at 48 hours of life, 8-

11 weeks, 14-16

weeks of age

>Assessed

spontaneous general

movements

- Infant

Developmental

Inventory

questionnaire at 1

year of age

> Assessed general

motor development

- Sleep questionnaire during

second trimester

- Sleep study during third trimester

- Brief Infant Sleep Questionnaire

at 1 year of age

- Hollingshead 2-factor index of

socioeconomic status

- No significant differences were

found between the maternal sleep-

disordered breathing and control

groups before and after adjustments

- No significant difference was found

in the gross and fine motor, language,

and self-help development scores

between the maternal sleep-


groups

- No significant differences in

nocturnal sleep duration, daytime

sleep, number of nocturnal

awakenings, sleep latency, and wake

after sleep onset and frequency of

problematic sleep were found

between the maternal sleep-


groups

68

Author

(Year)

Study


Neurodevelopment



development

Trasti et al.,

1999113

Prospective

cohort study

A sample of 376

mother-infant dyads

were recruited.

- Bayley Scales of

Infant Development,

1st edition at 13

months of age

> Assessed general

motor development

- Peabody

Developmental Motor

Scales

> Assessed general

motor development

- Maternal smoking status and

education


(HSQ)

- Wechsler Preschool and Primary

Scales of Intelligence

- At 13 months, children of smokers

and non-smokers performed equally

well on the mental and psychomotor

components of the Bayley Scales of

Infant Development

- IQ scores were significantly lower

among children of smokers compared

to children of non-smokers

- Significant differences were

observed in fine motor coordination

and balance between smokers and

non-smokers in adjusted models

- A dose-response relationship was

observed between the number of

cigarettes smoker per day during

pregnancy and the child’s balance

(increased number of cigarettes were

related to lower child scores)

Valtonen et

al., 2004114

Cross-

sectional

study

A sample of 434

children were selected

from the same age

cohort of children

registered at 16 children

health centers in

Finland.

- Lene test at 4 years

of age

- Assessed Motor-

Perceptual

development

- Child variables: sex, urban vs

rural residency

- Parent variables: education

- Isolated delays were general mild

- Co-occurring delays were more

frequently moderate or severe

Van der

Sluijs Veer

et al.,

2012115

Prospective

cohort study

A sample of 95 toddlers

with neonatal congenital

hypothyroidism were

recruited.

- Bayley Scales of

Infant Development,

2nd edition at 1 and 2

years of age

- Assessed general

motor development

- Heel puncture results, gestational

age, birth weight, treatment

strategy

- Mental development scores among

children with severe, moderate and

mild congenital hypothyroidism were

similar to the population at 1 year of

age, but the severe group was

significantly lower than the

population at 2 years of age

- Psychomotor development scores

among children with severe,

moderate and mild congenital

hypothyroidism were significantly

lower than the population at both 1

69

Author

(Year)

Study


Neurodevelopment



development

and 2 years of age

- Initial thyroxine concentrations and

starting dose of thyroxine were

significant predictors of mental

development at 1 year and

psychomotor development at 1 and 2

years

Vilahur et

al., 2014116

Prospective

cohort study

A sample of 423

infants-mother dyads

were recruited.

Pregnancies were

singletons without

assisted conception.

- Bayley Scales of

Infant Development,

1st edition at 14

months of age

- Assessed general

motor development

- Total effective xenoestogen

burden

- Sex, social class, and site of

recruitment


gestational age, type of delivery,

previous abortions, gestational

diabetes, marital status, maternal

age, height, BMI, gestational

weight gain, parity, smoking,

alcohol consumption,

breastfeeding practices, season of

birth, urbanicity, country of birth,

maternal education, paternal

height and weight, Apgar score

- No psychomotor differences

observed between sexes

- No significant differences between

xenoestrogen levels and mental or


Wehby et

al., 2008117

Cross-

sectional

survey

A subset of 6774

mother-child dyads


National Maternal

Infant Health Survey.

- Adapted from

Denver

Developmental

Screening Tools at 3

years of age

- Assessed general

motor development

- Prenatal use of vitamins and

minerals

- Covariates: prenatal care,

smoking, alcohol and recreational

drug use, maternal health, age

education, child age, sex, race,

number of children in household,

household income

- Folic acid supplementation was

associated with reduced odds for

moderate risk on the motor

development

- Calcium use was associated with

increased odds for high risk on

overall development and motor

development, and for moderate risk

on personal-social development

Wouldes et

al., 2014118

Prospective

cohort study

A subset of 103

methamphetamine

exposed infants and 107

non-exposed infants


New Zealand Infant

- Bayley Scales of

Infant Development,

2nd edition at 1,2 and

3 years of age

> Assessed general

motor development

- Substance use inventory:

quantity and frequency of prenatal

drug use

- Current household structure,

SES, quality of home environment


- No effects of methamphetamine

exposure on gross or fine motor

development at 1 year of age

- At 3 years of age, gross motor

development was significantly lower

among infants exposed to prenatal

70

Author

(Year)

Study


Neurodevelopment



development

Development,

Environment and

Lifestyle study.

- Peabody

Developmental Motor

Scale, 2nd edition at 1

and 3 years of age

>Assessed fine

and gross motor

development

Test, 3rd edition

- Covariates: gender, birth weight,

ethnicity, drug use, SES

methamphetamine compared to non-

exposed infants

- At 1 and 2 years of age,

methamphetamine exposed was

associated with lower psychomotor

scores compared to non-exposed

infants

-

Zwicker et

al., 2013119

Retrospective

cohort study


low-birth-weight

children were enrolled.

- Movement

Assessment Battery

for Children at 4-5

years of age.

- Assessed general

motor development

- Perinatal variables: antenatal

steroid use, premature rupture of

membranes greater than 18h,

mode of delivery, plurality, Apgar

scores, gestational age, birth

weight

- Neonatal variables: days of

supplemental oxygen, days of

ventilation, postnatal steroids,

patent ductus arteriosus,


retinopathy of prematurity, sepsis,

hyponatremia, cranial ultrasound

abnormalities

- Males, low-birth weight and

postnatal exposure to steroids were

independently associated with low

motor development scores

- Significantly more boys scored in

the range of developmental

coordination disorder than girls

71

2.2.1.1 Sociodemographic factors

The effect of socio-demographic characteristics on child motor development are

commonly assessed or controlled for in the literature61,62,75,81,82,85,90,92,102,106,118. The results

regarding the association between sociodemographic factors and motor development, however,

have been conflicting as evidenced by studies investigating the association of socioeconomic

status (SES) or parental age on motor development. For example, in their 3-year longitudinal

follow-up of 329 infants, Singer et al. did not find an association with socioeconomic status

(SES), classified using the Hollingshead Four-Factor Index of SES, and low motor scores (p-

value=0.89)106. In their prospective cohort study of 117 infants Mazer et al, however, found that

infants of families with moderated Hollingshead Index scores exhibited poorer psychomotor

development scores on the Bayley Scales of Infant Development compared with infants of

families with high Index scores81.

In the literature, the use of the Hollingshead Four-Factor Index of SES is uncommon;

rather studies typically employ proxy measures of SES including maternal education and

intelligence, employment status, household income and/or marital status58,61,69,70,74,79,90,97.

Associations between proxy measures of SES and motor development are well supported. For

example, while examining the interaction between maternal intelligence and child

neurodevelopment, Ronfani et al. evaluated the intelligence of 900 mothers using the Standard

Progressive Matrices, a test of nonverbal reasoning ability and general intelligence96. Through

their analysis, Ronfani et al. described that when comparing the highest quintiles of maternal

intelligence to the lowest, increased maternal intelligence was associated with higher infant

motor development scores on the Bayley Scales of Infant and Toddler Development-III at 18

months of age.

72

Similar associations have also been described between years of maternal education and

child motor development. In a prospective cohort study of 6850 infants from the Early

Childhood Longitudinal Study – Birth Cohort, Hinkle et al. suggested that increased maternal

education was associated with higher psychomotor development scores on the Bayley Scales of

Infant Development-II70. In addition to reporting lower motor scores among infants of mothers

with low maternal education, Hinkle et al. also reported lower scores among infants of

single/unmarried mothers, an association also well supported by the literature74,80,147. The

prospective nature, large sample size and rigorous methodology of both these studies provide

strong evidence for an association between proxy measure of maternal SES and infant motor

development70,96.

Parental age has also been shown to be associated with motor

development69,74,80,144,145,147. In their assessment of 915 toddlers involved in the Avon

Longitudinal Study of Parents and Children, Little et al., described that poorer locomotor scores

18 months of age were associated with increased maternal age80. Furthermore, Majnemer et al.

described in both their cross-sectional145 and cohort analysis144, that both increased maternal and

paternal age were associated with decreased motor scores on the Alberta Infant Motor Scales.

The literature reporting on the influence of ethnicity and a child’s sex on general motor

development is supported by evidence from methodologically robust studies. In the analysis of

4901 children from the longitudinal Upstate KIDS cohort of New York, Wylie et al. described

that children of non-Hispanic white mothers took longer to crawl and to stand alone compared

with other ethnicities161. Moreover, children of Latina mothers have been shown to score lower

on the Bayley Scales of Infant Development Psychomotor Development Index (p-value<0.05)65.

Lower motor and social development among Mexican-Americans was also reported by Hediger

73

et al. in their analysis of the third National Health and Nutrition Examination Survey conducted

in the USA69.

Finally, among studies that found associations between motor development and the

child’s sex, males have frequently shown to exhibit poor motor development compared with

females69,70,73,90,154. For example, in their analysis of 348 children aged 13 months, Janssen

demonstrated that males scored significantly lower on the psychomotor subscales of the Bayley

Scales of Infant Development, second edition, compared to females73. Using the same

assessment of neurodevelopment, Hinkle et al. reported similar results in their aforementioned

analysis70; among 6850 children 20-38 months of age, males exhibited significantly lower

psychomotor motor scores than females.

In sum, an association between SES, ethnicity65,69,161 and a child’s sex69,70,73,90,154, and

general motor development is clearly supported in the literature. Although the results for the

independent associations between factors such as living and housing arrangements51,58,96, urban

or rural residency63,114 and whether the family receives support from the government72,77 and

motor development are not presented in the literature, models are commonly adjusted for these

factors.

2.2.1.2 Maternal health factors

The research investigating the influence of maternal health on general motor

development has included studies considering aspects of both maternal physical and mental

health. For example, in Wylie et al.’s analysis of the longitudinal Upstate KIDS study, they

described the long-term effects of pre-pregnancy obesity on early child development161. In their

study, infants born to obese, but not overweight, mothers exhibited delays in early motor

74

milestone attainment (i.e. sitting without support and crawling) compared with infants of thin or

normal-weight mothers. Given the association between maternal obesity and motor development,

studies commonly control for maternal BMI before70,96 and during116 pregnancy, gestational

weight gain116 and weight postpartum108.

Along with their investigation of the influence of pre-pregnancy maternal BMI on motor

development, Polanska et al., also studied maternal leisure-time physical activity and folic acid

supplementation on the motor outcomes of 538 children involved in the Polish Mother and Child

Cohort Study92. Their analysis revealed a significant association between poor motor

development at both 1 and 2 years of age with both decreased leisure-time physical activity and

failure to supplement with folic acid. Though the analysis of maternal leisure-time physical

activity is unique in the literature, other studies have revealed similar associations between folic

acid supplementation and motor development. In a 2009 prospective, longitudinal analysis of

482 mother-baby dyads, Julvez et al. described a significant increase in motor scores at 4 years

of age (p-value<0.01) among children born to mothers taking folic acid supplements75. As

Spain’s 2008 state-level survey data suggests that only 0.13-12.8% of the population were folate

deficient120, the folic acid supplementation in this study may have represented doses higher than

recommended. Moreover, based on the state level survey data120, mothers not taking folic acid

supplements were likely not folate deficient. As such, these results support the importance of

folic acid supplementation during pregnancy for motor development75,92.

The relationship between maternal seafood consumption and child neurodevelopment has

also been investigated. In a prospective cohort study in 2008, Mendez et al. reported that infants

of mothers consuming fish greater than 2-3 time per week exhibited significantly higher scores

on all subscales of the McCarthy Scales of Children’s Abilities test84. No significant differences,

75

however, were observed among mothers eating other forms of seafood excluding fish (i.e.

shellfish) or child consumption of seafood.

In additional to maternal physical health, the literature has also explored the effects of

maternal mental health on general motor development. The importance of factors influencing

maternal mental health on child neurodevelopment is reflected by the numerous studies

investigating the effect of perceived stress, depression, anxiety, social support or parental

interactions on motor development51,57,58,60,68,71,74,77,93,95,103-105,147,150. For example, Huizink et al.

examined the effects of maternal anxiety and stress during pregnancy on developmental

outcomes of 170 singleton infants at 3 and 8 months of age71. In this prospective cohort study,

maternal anxiety measured as a strong fear of giving birth by mothers during mid-pregnancy (27-

28 weeks’ gestation) was related to poor psychomotor development scores by infants 8 months

of age on the Bayley Scales of Infant Development (p-value<0.01). Moreover, high salivary

cortisol levels during late pregnancy (37-38 weeks’ gestation) were also related to poor

psychomotor development scores at both 3 and 8 months of development (3-months: p-

value<0.01; 8 months: p-value<0.05).

Recently, the effects of alcohol59-61,63,71,72,75,77,79,82,85,90,92,93,95,96,100,103-105,111,154,

cigarettes52,61,75,79,82,85,90,95,103-105,154, cocaine72,77,82,85,90,95,100,103-105,154, marijuana72,77,82,85,90,95,100,103-

105,154, opiates72,77,82,109 and other illicit77,100,103-105 drugs during pregnancy on motor development

have been explored. Amongst others, Polanska et al. and Singer et al. described a significant

association between cigarettes92 or cocaine106 use during pregnancy and motor development

delays. Moreover, the results from Richardson et al.’s analysis of 320 mother-baby dyads

participating in a one-year follow-up study suggest that maternal self-report of alcohol

consumption during any trimester, or cocaine use during the second trimester may significantly

76

affect general motor development95. Finally, fetal exposure to opiates during pregnancy,

validated using meconium screening, was associated with children exhibiting significantly lower

psychomotor development scores on the Bayley Scales of Infant Development, compared to

children with no opiate exposure82. Together, these cohort studies provide strong evidence for an

association between prenatal drug and alcohol use, and delayed motor development given their

prospective nature and large sample sizes.

Maternal physical and mental health, and lifestyle have been shown to influence motor

development. The affect of maternal BMI and folic acid supplementation on child motor

development is well reported in the literature75,92,116,161. Moreover, many cohort studies have

described associations between maternal consumption of alcohol, tobacco or illicit drugs during

pregnancy and poor motor development59-61,63,71,72,75,77,79,82,85,90,92,93,95,96,100,103-105,111,154. Given the

scarcity of studies directly investigating maternal optimism and parenting morale, further

prospective research is required to understand the influence of these factors on motor

development.

2.2.1.3 Pregnancy and birth outcome factors

Given the increased survival rate of babies born prematurely, many studies have

investigated the long-term influence of gestational age and birth weight on motor developmental

outcomes51,52,56,61-63,65,67,70,71,73-75,78,82,86,89,92,96,106,107. In their recent longitudinal study

investigating 371 children born <32 weeks’ gestation and admitted to the neonatal intensive care

unit (NICU), Janssen et al., described that nearly 40% of the children born preterm exhibited

motor developmental delays73. Moreover, Wiley et al. described that preterm birth, low birth

weight (i.e. <2500g) and small-for-gestational-age were all risk factors for poor motor milestone

77

attainment161. Similar studies have also shown that decreased head circumference and small-for-

gestational-age infants are at increased risk for overall motor delay78,90,148. Though children

considered small-for-gestational-age typically undergo catch-up growth, evidence suggests that

their delays in motor development persist past 2 years of age.

Due to intrauterine growth restrictions, multiple birth pregnancies are typically excluded

from many studies in the literature. Datar et al., however, included twins in their longitudinal

analysis investigating the effect of birth weight on child development at 9 months and 2 years of

age in America63. Using 6,750 singleton births, 625 twin pairs (525 fraternal, 100 identical) and

50 twins and other higher-order births, their study failed to find an association between low-birth

weight and poor motor development. As twins were included in the study, both genetic and

environmental factors were controlled. Therefore, even though low-birth weight was

significantly associated with poor motor development based on cross-sectional data, within-twin

comparisons for both fraternal and identical twins did not find an association between birth

weight and motor development. This study contradicts the previous evidence provided in the

literature69,106,145,154 and reveals that when maternal, environmental and genetic factors are

controlled for, birth weight is not significantly associated with motor development at 9 or 24

months of age.

Beyond studies investigating gestational age, birth weight and delivery type51,52,56,61-

63,65,67,70,71,73-75,78,82,86,89,92,96,106,107, few studies have investigated the effect of other pregnancy or

birth outcomes. Though it is common for studies to adjust models according to NICU admission

and Apgar scores52,60,97.98,103-107,119, the independent associations between these variables and

motor development are not described. As such, description for the association between

pregnancy and birth outcome factors, such as intrauterine growth restrictions, Apgar scores,

78

NICU admission, antenatal steroid use and pregnancy complications, and motor development are

required.

2.2.1.4 Child health factors

Though there are a myriad of child health complications that may influence motor

development, studies have generally targeted cardiovascular disorders, neurological disorders

and neonatal conditions73,78,89,91,107. For example, in their analysis of bronchopulmonary

dysplasia and motor development, Singer et al. also investigated the effects of patent ductus

arteriosus, neurologic risk scores, intraventricular hemorrhage, septicemia and retinopathy of

prematurity on motor development107. Among their cohort of 329 infants 16-18 months of age

they found that bronchopulmonary dysplasia and neurologic risk score were significantly

associated with poorer motor outcomes on the Bayley Scales of Infant Development.

Intraventricular hemorrhage, patent ductus arteriosus, septicemia and retinopathy of prematurity

were not associated with motor development. A case-control study by Ohman et al. also

suggested that congenital muscular torticollis was associated with poor motor development at 2

and 6 months of development91.

Evidence for the long-term effect of children’s’ physical health on motor development

has also been described. In an analysis of 217 infants enrolled in the Infant Care, Feeding, and

Risk of Obesity Project, a longitudinal study of low-income African American mother-infant

dyads, Slining et al. investigated infant weight and its influence on motor development108.

Within this cohort, overweight infants had 1.67 (95% CI: 1.01-2.79) times the odds of exhibiting

motor development delays of normal-weight infants. Moreover, infants with high subcutaneous

fat had 2.21 (95% CI:1.18-4.14) times the odds of motor delay when compared with infants with

low subcutaneous fat. These results, however, differ from a similar analysis of 37 preterm infants

79

in a longitudinal study in Japan76. In their study, Kanazawa et al. described a correlation between

increased subcutaneous fat gain and increased motor ability41. Using ultrasound imaging,

Kanawaza et al. also noted that motor development was not significantly correlated with muscle

size. These conflicting results may be due to the small sample size in Kanazawa et al.’s study

and therefore their inability to control for potential confounders. Moreover, as 29% of infants 18

months of age assessed by Slining et al. scored >90th percentile in weight-for-length z-scores108,

their sample may have been significantly more obese than the sample of infants 18 months of age

assessed by Kanazawa et al76l. As such, increased subcutaneous fat may be associated with

increased motor achievement among normal weight infants, however, excess subcutaneous fat

may be a risk factor for delayed motor development.

The co-occurrence of chronic developmental disorders and motor development has also

been reported. In a longitudinal analysis of 434 Finnish children, Valtonen et al. found that

delayed motor development was associated with co-occurring developmental delays, such as

attention-behavioural and language delays114. In addition to the increased risk of motor

developmental delays, the severity of the delay was higher when they co-occurred with other

delays.

In sum, the literature supports the association between a child’s history of medical

conditions, excess weight and co-occurrence of developmental disorders, and delayed motor

development.

2.2.1.5 Environmental factors

A child’s environment has been shown to be highly influential on their motor

development72,77,79,82,88,93,95,100,103-105,113. It has been hypothesized that children of low-income

80

families may have less stimulating environments, such as less space inside the home to safely

explore, fewer age appropriate toys and less parent-child interaction time, increasing the risk of

developmental delay177,178. Evidence supporting this hypothesis is described by Piteo et al. by

evaluating the home environment using the Home Screening Questionnaire (HSQ)151. In their

case-control study, children with more stimulating home environments exhibited higher

cognitive, language and general motor development scores. Similar results were also described

by Messinger et al., in their analysis of a subset of 1227 American mother-children dyads from

the Maternal Lifestyle Study, a prospective cohort study82. In their analysis, higher HOME

scores, indicative of more stimulating home environments, were associated with higher

psychomotor scores on the Bayley Scales of Infant Development, second edition.

In addition to creating a stimulating home environment, parenting resources have also

been shown to influence motor development. For instance, Black et al.58, Wiley et al161., Hinkle

et al.70 and Nelson et al.90 described that increased parity was associated with poor motor

development23,26. Moreover, Polanska et al. suggested that the increased number of siblings in a

home is also associated with poor motor development92. These results align the hypothesis that

with each additional child, parental support becomes diluted144,185 resulting in less available

resources aimed at supporting the child in their developmental progression.

Finally, the effect of how a child interacts with their environment on their motor

development has also been examined. In 2006, Majnemar et al. examined the effect of sleeping

position on 121 children’s motor development144. This study revealed that children put to sleep

in the prone position had significantly better motor scores than those put to sleep in the supine

position. Moreover, children spending more awake time in the prone position also had

significantly better motor scores than those spending more time in the supine position. Studies

81

investigating sleeping position, however, face many limitations, including misclassification bias

resulting from a child’s ability to change their sleeping position as they age144,145. Moreover, due

to recommendations by organizations including the Canadian Pediatric Society that encourages a

supine sleeping position due to its association with lower rates of sudden infant death syndrome,

few children slept in the prone position144,145. Therefore, results from these studies lack a

sufficient number of infants sleeping in the prone position to compare the association between

sleep positions and motor development.

Currently, the best quality evidence suggests that the home environment influences motor

development. Given the popularity of computers and tablets, future research should investigate

the influence of various types of stimulations available to children in their home environment on

motor development55.

2.2.2 Risk Factors for Delayed Fine or Gross Motor Development

As screening tools continue to adapt to accommodate new insights into child

development, studies are increasingly able to differentiate between risk factors for either fine or

gross motor development128. The influence of socio-demographic, maternal health, pregnancy

and birth outcome, child health, and child environmental risk factors on either fine or gross

motor development are described here. A summary of the included articles assessing fine and

gross motor development are presented in Table 3.

82

Table 3. Summary of articles examining factors associated with fine and/or gross motor development in children 1-66 months

of age

Author

(Year)

Study

Design

Study

population

Neurodevelopment

Test Factors investigated Results related to motor development

Arendt et

al., 1999120

Prospective

cohort study

A sample of 260

infants and young

children were

recruited from a

newborn nursery

or at-risk pediatric

clinic.

- Peabody

Developmental Motor

Scales (PDMS) at 2

years of age.

- Assessed fine and

gross motor

development

- Mother’s demographics and

medical information

- Infant demographics and

medical information

- Maternal Postpartum Drug

Interview

- Tobacco, alcohol, marijuana

and cocaine use

potential confounders: infant

race, gender, 5-minute APGAR

score, gestational age, length,

weight, head circumference,

number of prenatal visits,

marital status, age at delivery,

education level, family income,

number of persons living in the

home.

- Cocaine exposed children did significantly

poorer than non-exposed children in the

following: Fine motor development (hand

use, eye-hand coordination, total score) and

gross motor development (balance, receipt

and propulsion)

- Significant correlations with gross motor

development: maternal age, alcohol month

before pregnancy or during first trimester,

cocaine use during first trimester,

gestational age, birth weight and length

- Significant correlations with fine motor

development: maternal age, cocaine use

during first trimester, gestational age, birth

weight and length, head circumference

- Confounding both fine and gross motor

development: maternal age, education and

number of prenatal visits

Regression for fine motor development:

Cocaine exposure was a significant

predictor of hand use and eye-hand

coordination.

Regression for gross motor development:

severity of alcohol use before pregnancy

predictor for receipt and propulsion subscale

Austin et al.,

2013121

Prospective

cohort study

A sample of 35

antidepressant-

exposed infants

and 23 non-

exposed infants

were recruited.

Mothers in the

exposed group

used

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Assessed both fine

and gross motor

development

- Demographic and clinical

information (age, marital status,

obstetrical history, education

level, cigarette, alcohol and

recreational drug use during

pregnancy, perinatal outcomes)

- Medication Calendar (name

and dosage and compliance of

antidepressant use)

- Antidepressant exposed infants did not

score significantly different on cognitive,

receptive language, expressive language,

fine motor or gross motor development than

non-exposed infants

83

Author

(Year)

Study

Design

Study

population

Neurodevelopment


antidepressant for

1 month during

pregnancy.

Mothers in

control group had

no history of

mood disorders

and not using

antidepressants or

psychotropic

medication. No

mothers currently

used alcohol or

illicit drugs,

diagnosed with

other mental

health disorders

or significant

obstetrical

history.

- Edinburgh Postnatal

Depression Scale

- National Adult Reading Test

- MINI-Plus interview for

mental health disorders

Bigsby et

al., 2011122

Prospective

cohort study

A sample of 370

cocaine-exposed

infants and 533

non-exposed

infants were

recruited into the

Maternal

Lifestyle Study.

Mothers were

older than 18

years of age,

mostly African

American with at

least a high

school education.

- Posture and Fine

Motor Assessment of

Infants

- Assessed postural

and fine motor

development

- Legal and illegal drug use

during pregnancy (cocaine,

alcohol, marijuana, tobacco)

- Groups were matched on

gestational age, race and gender

- Cocaine exposed infants scored lower than

control infants on postural scores when

controlling for testing site, gestational age,

SES and, prenatal exposure to alcohol,

tobacco and marijuana

- Infants <33 weeks’ gestation scored lower

on postural and fine scores than infants >33

weeks’ gestation

- No significant effect of SES or, cocaine,

alcohol or tobacco use on either postural or

fine motor scores

- Prenatal exposure to marijuana did

significantly affect fine motor scores

Case-Smith,

1993123

Prospective

cohort study

A sample of 65

full-term and 25

- Posture and Fine

Motor Assessment of

- Corrected gestational age

- Medical Risk

- Preterm infants scored lower on all aspects

of postural control and fine motor skills

84

Author

(Year)

Study

Design

Study

population

Neurodevelopment


preterm infants

were recruited.

Full-term infants

were born within

2 weeks of due

date, healthy

histories, no

unusual medical

procedures or

problems. Preterm

were born prior to

37 weeks’

gestation,

weighed 2000

grams or less and

had one or more

significant

medical problems

during the

neonatal period.

Infants

- Assessed postural

and fine motor

development

- Postural control was significantly greater

in full-term infant than high risk preterm

infants

- Fine motor skills were significantly greater

in full term infants than both high and low

risk preterm infants

Carmeli et

al., 2008124

Prospective

cohort study

A sample of 80

full-term infants

were recruited

into the study. All

infants were born

to unmedicated,

uneventful

pregnancies and

deliveries from

non-smoking,

non-alcoholic

two-parent

families.

- The Alberta Infant

Motor Scale (AIMS)

at 6 months of age

- Assessed gross

motor development.

- Sleep position log (position put

to sleep and position upon

awakening)

- Position while awake

- Preferred position

- Duration of play position

- No significant correlations between infant

positions and motor development were

found

Cruise &

O’Reilly,

2014125

Prospective

cohort study

A sample of

10748 nine-

month-old infants

were recruited in

- Ages and Stages

Questionnaire, 2nd

edition at 9 months of

age

- Socio-environmental

information: partner resident in

the household, number of

siblings in the house, infant

- Risk of poor gross motor development:

one or more sibling, gestational age 25-36

weeks, birth weight <2500 grams, mothers

age 35+ years

85

Author

(Year)

Study

Design

Study

population

Neurodevelopment


the Growing Up

in Ireland study.

- Assessed fine and

gross motor

development

receiving non-parental care from

a relative, non-relative, or a

center

- Confounding variables:


gender, maternal ethnicity, age,

education, household income,

living in urban or rural setting

- Protective factors for gross motor

development: birth weight 3501-4000grams,

not Irish white

- Risk of poor fine motor development:

gestational age 25-36 weeks, male, mothers

age between 16-19 or 20-24, only secondary

education

De Kegel et

al., 2016126

Prospective

cohort study

A sample of 64

children

diagnosed with

congenital

cytomegalovirus

infections were

enrolled. In the

sample, 26 infants

were symptomatic

and 38 were

asymptomatic.

The infected

children were also

compared to 107

uninfected,

typically

developing

children.

- Peabody

Developmental Motor

Scales, 2nd edition,

Alberta Infant Motor

Scales and Ghent

Developmental

Balance Test at 6, 12

and 24 months of age,

in randomized order

- Assessed gross and

fine motor

development and

balance

- The symptomatic group performed worse

than the control group for all gross motor

outcomes at 6, 12 and 24 months and worse

than the asymptomatic group on PDMS

gross and the AIMS at 6 and 12 months, and

the GDBT as 24 months

- Asymptomatic group performed weaker

than control group in gross motor at 12 and

24 months

- Symptomatic and asymptomatic groups

gave greater risk of gross motor delays, but

for the asymptomatic group this may be

related to sensorineural hearing loss

Eek

Brandlistuen

et al.,

2013127

Prospective

cohort study

A subset of 48631

children from the

Norwegian

Mother and Child

Cohort Study

were used in this

study. Within the

sample there were

2919 same-sex

sibling pairs who

were used to

- Ages and Stages

Questionnaire at 36

months of age

(assessed fine and

gross motor

development)

- Age child began

walking unassisted

- Paracetamol and Ibuprofen

use: gestational age of exposure,

age of exposure postpartum,

number of days of use at each

time point

- Behaviour: externalizing and

internalizing behaviour

measured by the Child

Behaviour Checklist

- Temperament: Emotionality,

Activity and Shyness

- In the sibling-control analysis, long-term

paracetamol exposure (>28 days) associated

with poor gross motor functioning, delayed

age of walking, poor communication skills,

externalizing and internalizing behaviour

problems, and active temperament

- No interaction effect between trimester

and exposure on any outcome

- In the cohort analysis, long-term

paracetamol exposure associated with poor

gross motor functioning, poor

86

Author

(Year)

Study

Design

Study

population

Neurodevelopment


adjust for familial

and genetic

factors.

Temperament Questionnaire

- Potential Confounders:

maternal health before and

during pregnancy, fever, back

pain, head ache or migraine, use

of nonsteroidal anti-

inflammatory drugs, triptans,

opioids, other analgesics,

antipsychotics, antidepressants,

benzodiazepines, antiepileptic

drugs, maternal age, years

between pregnancies, parity,

smoking and alcohol use during

pregnancy, maternal education,

and maternal chronic diseases

- Hopkins Symptom Checklist

(psychological distress)

communication skills, externalizing

behaviour problems, and negative

emotionality

- In the sibling-analysis, short term

paracetamol exposure (<28 days) was

associated with poor gross motor

functioning

- In the cohort analysis, short term

paracetamol exposure was associated with

poor gross motor development,

externalizing behaviour and negative

emotionality

- No associations between ibuprofen and

any of the outcomes in adjusted models

Evlampidou

et al.,

2007128

Prospective

cohort study

A subset of 179

mother-baby

dyads from the

Rhea Study in

Crete, Greece.

- Bayley Scales of

Infant and Toddler

Development, 3rd

edition at 18 months

of age

- Assessed fine and

gross motor

development

- Detailed information on

sociodemographic information,

smoking, dietary, and lifestyle

patterns

- Smoking during pregnancy:

total cotinine levels in urine at

12th and 30th week of pregnancy

- Exposure to second-hand

smoke

- Poorer gross motor development scores

were associated with increased urinary

cotinine levels. No other domains exhibited

associations with urinary cotinine levels

- No associations between sex and gross

motor development in adjusted models

Galbally et

al., 2011129

Case-control

study

A sample of 22

antidepressant

exposed infants

was matched to

19 unexposed

infants. Eligibility

required that

women not have a

substance

dependence,

- Bayley Scales of

Infant Development,

third edition at mean

age of 23.09 months

(SD: 3.82) for the

control group and

28.53 months (SD:

6.22) for the exposed

group.

- Maternal Characteristics:

demographics, reproductive and

medical history, alcohol, tobacco

or illicit drug consumption,

prescription medication use,

maternal stress, marital status,

employment and mental health

services utilization

- Birth Outcomes: delivery

method, gestational age,

- No association found between

developmental outcomes and antidepressant

use (study under-powered)

- Significant association between higher

expressive language performance and

increased depression rating during

pregnancy

87

Author

(Year)

Study

Design

Study

population

Neurodevelopment


intellectual

disability, serious

physical illness or

psychiatric

illness. Women

were also

proficient in

English.

- Scores were scaled

to correct for age

differences

- Assessed fine and

gross motor

development

APGAR scores, birth outcome

and perinatal complications

- Antidepressant use: type,

dosage and duration of exposure

- Beck Depression Inventory, 2nd

edition

Ghassabian

et al.,

2015130

Prospective

cohort study

A subset of 4909

mother-child

dyads from the

Upstate KIDS

cohort study were

examined.

- Six gross motor

milestones: sitting

without support,

standing with

assistance, hands-

and-knees crawling,

walking with

assistance, standing

alone, walking alone

- Used WHO 90th

centile’s

- Pregnancy information:

gestational

diabetes/hypertension/eclampsia,

pre-eclampsia, HELLP

syndrome

- Medical history: chronic

diabetes mellitus, hypertension,

hypothyroidism,

hyperthyroidism, cardiovascular

disease, autoimmune disorders

- Maternal and child

information: maternal age,

education, race/ethnicity, history

of smoking, alcohol

consumption, gestational age,

birth size and sex

- Infants of mothers with gestational

diabetes took longer to walk with assistance

- No significant delays among infants of

mothers with gestational hypertension in

adjusted models

- No significant delays among infants of

mothers either pre-eclampsia, eclampsia or

HELLP syndrome in adjusted models

- Compared to unexposed infants, infants of

mothers with diabetes took longer to stand

with assistance, walk with assistance, and

walk alone

- No associations found with maternal

chronic hypertension, hypothyroidism,

hyperthyroidism before or during pregnancy

and gross motor development

- Maternal cardiovascular disease was

associated with a shorter time to walking

alone, whereas autoimmune disease was

associated with a longer time to achieve

crawling.

Gonzalez-

Valenzuela

et al.,

2015131

Retrospective

cohort study

A subset of 146

children were

randomly selected

from a newborn

registry of 7465

in Spain.

- Batelle

Developmental

Inventory at a mean

age of 56.32 months

(SD=3.42 months)

- Assessed both fine

- Exposure to synthetic oxytocin

during delivery

- Control variables: maternal

age, type of labor, duration of

labor, twin pregnancy, sex and

gestational age

- Significant association between gross and

fine motor development delays and

exposure to synthetic oxytocin

- Labor longer than 4 hours and being male

were also associated with gross motor

delays

- No significant associations between fine

88

Author

(Year)

Study

Design

Study

population

Neurodevelopment


and gross motor

development

motor development and control variables

- Exposure to synthetic oxytocin associated

with gross motor delays, and relationship

influence by the child’s sex

-

Goyen &

Lui, 2002132

Prospective

cohort study

A sample of 85

children were

recruited. Of the

85 children, 13

were lost-to-

follow-up and 14

had missed one of

the three

assessment

periods.

Therefore,

longitudinal

analysis was

performed on 58

eligible infants.

- Peabody

Developmental Motor

Scales at 18 months,

3 and 5 years of age

- Assessed fine and

gross motor

development


Maternal Environment (HOME)

Scale

- Griffiths Mental

Developmental Scales

- No significant difference in gross or fine

motor development by sex

- Micropreemies, had significantly lower

gross and fine motor development at 5 year,

while infants from homes with low HOME

scores had lower gross and fine motor

development scores at 18 months and 5 year

of age

Gray et al.,

1999133

Prospective

cohort study

A sample of 84

consecutively

born neonates

with intrauterine

growth

restrictions and 81

appropriately

grown control

infants were

enrolled. Controls

were the next

appropriately

grown infants of

the same sex,

ethnic

background and

gestational age

- Neuro-Sensory

Motor Developmental

Assessment at 4

months of age

- Assessed fine and

gross motor

development

- Intrauterine growth restrictions

(birth weight more than 2 SDs

below mean for gestational age)

- Placental pathology

- Pregnancy history:

hypertension, diabetes mellitus,

alcohol, tobacco and drug use

during pregnancy, labour details,

fetal distress, baby’s condition at

birth and during the neonatal

period

- Infant birth weight, length,

head circumference, mid-arm

circumference

- Growth parameters: weight,

length, BMI, mid-arm

circumference, head

- Placental infarction and accelerated villous

maturation was significantly associated with

intrauterine growth restriction cases

- No significant difference across any

developmental domains on the Griffiths

Scale or the Neuro-Sensory Motor

Developmental Assessment between the

intrauterine growth restriction group and the

appropriately grown control group

89

Author

(Year)

Study

Design

Study

population

Neurodevelopment


and whose parents

were from

Brisbane.

circumference

- Griffiths Infant Development

Scale

Handal et

al., 2015134

Prospective

cohort study

A sample of

51404 singleton

pregnancies were

assessed from the

Norwegian

Mother and Child

Cohort Study

- Ages and Stages

Questionnaire at 3

years of age

- Assessed gross and

fine motor

development

- Exposure to selective serotonin

reuptake inhibitors (before and

during pregnancy)

- Depression before pregnancy,

- Hopkins Symptom Checklist:

test for anxiety and depression

- Parental characteristics: age,

education, marital status, parity,

planned pregnancy, maternal

work situation, maternal BMI,

maternal smoking, maternal

opioid (analgesic) and

benzodiazepine during

pregnancy and alcohol during

pregnancy

- Fine and gross motor development was

associated with parental education, paternal

age parity, maternal smoking, depression

before pregnancy and anxiety and

depression after pregnancy

- prolonged SSRI use increased the odds

ratio of lower fine motor development

- “weak” association between fine and gross

motor development and the use of selective

serotonin reuptake inhibitors during

pregnancy

Hanley et

al., 2013135

Prospective

cohort study

A sample of 31

mother-child pairs

exposed to

serotonin

reuptake

inhibitors and 52

mother-child pairs

unexposed.

- Bayley Scales of

Infant Development,

3rd edition at 10

months of age

- Assessed fine and

gross motor

development

- Serotonin Reuptake Inhibitor

expose

- Demographics, reproductive

and medical history, and

prescription medication history

- Neonatal outcomes: gestational

age, birth weight and length,

head circumference, and Apgar

scores


Depression Scale for Depression

- Hamilton Rating Scale for

Depression

- Positive and Negative Affect

Scale

- Poor gross motor development scores were

observed among infants exposed to

serotonin reuptake inhibitors, when

controlling for depression during pregnancy

and at time of assessment, and alcohol and

tobacco use.

- Lower social-emotional and adaptive

behaviours were also reported by others of

exposed infants, controlling for maternal

mood at 36 weeks’ gestation and at 10

months postpartum, smoking and alcohol

use.

- No significant associations between any

developmental outcomes and maternal

depression

- Smoking during pregnancy was associated

with decreased expressive communication

scores at 10 months

90

Author

(Year)

Study

Design

Study

population

Neurodevelopment


Hanson et

al., 2011136

Cross-

sectional

study

A sample of 176

children aged 2-

34 months were

enrolled.

- Peabody

Developmental Motor

Scales, 2nd edition at a

mean age of 15.38

months (SD: 8.39

months)

- Assessed gross

motor development

(fine motor

development not

included)

- Growth Parameters: height,

weight and head circumference,

gender

- Chronological and gestational

ages

- Placement type (foster care,

kinship care, in-home protective

services; type of child welfare)

- Time with child welfare

- Number of placements

- Prenatal exposure to illicit

drugs

- Reason for placement: physical

or sexual abuse, neglect, medical

neglect, abandonment, housing

problems, parental substance

abuse, maternal mental illness,

abuse of siblings, maternal

incarceration or other

- Significant positive correlation between

weight-for-height and gross motor scores

- Compared to other reasons, children

involved with child welfare due to abuse or

neglect, medical neglect and parental

substance abuse had lower gross motor

quotients and those involved due to

abandonment had higher scores

- Significant differences between gross

motor quotient means between those

entering child welfare due to medical

neglect compared to all types of abuse or

neglect

- Significant difference in gross motor

quotient between those staying in kinship

care versus foster care, and those staying in

kinship care versus in-home protective

services (children in kinship care had

highest scores)

Keim et al.,

2011137

Prospective

cohort study

A subset of 358

infants were

recruited from the

Pregnancy,

Infection, and

Nutrition Study.

- Mullen Scales of

Early Learning at 12

months of age

- Assessed fine and

gross motor

development

- State-Trait Anxiety Inventory

- Centers for Epidemiologic

Studies Depression Scale


Depression Scale

- Gestational age, income, pre-

pregnancy BMI, education,

social support, self-esteem,

maternal age, infant sex,

gestational age, presence of

spouse/partner, perceived stress

- Anxiety, stress and depression were

associated with younger maternal age, low

self-esteem, low income and low education.

Anxiety and depression were also associated

with low social-support, or absence of

spouse/partner. Depression was also

associated with higher BMI.

- Infant of older and more educated mothers

had higher fine motor scores. Preterm

infants had lower fine and gross motor

scores, and lower composite scores.

- Associations between trait anxiety,

perceived stress and depression with gross

motor development were U-shaped. Low

and high anxiety and depression were

associated with higher scores, whereas

moderate exposure was associated with

91

Author

(Year)

Study

Design

Study

population

Neurodevelopment


poorer scores.

- High depression scores were also

associated with better fine motor

development

- Perceived stress was positively associated

with cognitive ability and expressive

language ability

Kelly et al.,

2006138

Prospective

cohort study

A subset of 15994

children from the

Millennium

Cohort Study

were assessed.

- Adapted from the

Denver

Developmental

Screening Test at a

mean age 9.2 months

> Assessed fine

and gross motor

development

- Adapted from

McArthur

Communicative

Development

Inventory at mean age

9.2 months

> Assessed

communicative

gestures

- Ethnicity: Black Caribbean,

Black African, Bangladeshi,

Indian, Pakistani, White, other

- Biological: sex, gestational

age, parity, maternal age,

illnesses requiring doctor,

hospitalizations

- SES: income, overcrowding

(>1.5 people/room), damp in the

home, no heating

- Culture: language spoken at

home, maternal country of origin

- House: Lone parent, number of

siblings in the household,

grandparents in the household,

other adults living in the

household

- Interaction: maternal

employment status, other infant

carers, maternal Malaise

Inventory, maternal attitudes to

childcare

- Black African, Black Caribbean, Indian,

mixed ethnicity had the highest rates of

normal development

- Bangladeshi and Pakistani had the lowest

rates

- Black Caribbean infants were less likely to

have gross motor delays, but had normal

rates of fine motor and communicative

gestures delays

- Bangladeshi infants had only slightly

higher rates of gross motor delays, but

nearly twice the average levels of fine motor

delay

- White infants were used as reference group

as they were the largest category.

- In fully adjusted model, Indian, Black

Caribbean and Black African were

significantly less likely to have gross motor

delays

- No significant differences were observed

for fine motor development in the fully

adjusted model

Koutra et

al., 2013139

Prospective

cohort study

A subset of 470

mother-child

dyads were

assessed from the

Rhea Cohort

Study. Women

spoke Greek and

were older than

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Assessed fine and

gross motor

development

- Antenatal Psychological

Assessment

- Edinburg Postnatal Depression

Scale

- State-Trait Anxiety Inventory

- Eysenck Personality

Questionnaire-Revised

- Maternal mental health:

- High levels of antenatal maternal

depressive symptoms were associated with

decreased cognitive development

- Increasing anxiety or increased

extraversion was associated with increased

social-emotional development

- increased trait anxiety or neuroticism was

associated with increased expressive

92

Author

(Year)

Study

Design

Study

population

Neurodevelopment


17 years of age

with singleton

pregnancies.

antenatal depression, trait

anxiety, personality traits

- Potential confounders: sex,

quality of assessment, delivery

type, gestational age,

breastfeeding duration,

childcare, maternal age at

delivery, maternal education,

maternal origin (i.e. Greek vs

non-Greek), parity, employment

status

communication

- High postpartum depression was

associated with decreased cognitive and fine

motor development

Koutra et

al., 2012140

Prospective

cohort study

A subset of 605

infants from 593

pregnancies were

assessed from the

Rhea Cohort

Study. Women

spoke Greek and

were older than

17 years of age.

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Assessed fine and

gross motor

development

- Socio-demographic

characteristics: parental age,

education, origin, marital status,

parity, maternal employment

status, gestation age, type of

delivery and anthropometric

measurements at birth

- Cognitive development (univariate): sex,

preterm, singleton, siblings, ICU, maternal

education, paternal education, maternal

employment; (Multivariate better outcomes)

high maternal education, only child,

singleton, girl

- Receptive-communication: (univariate)

sex, preterm birth, siblings, hours with

father per day, maternal origin, paternal

origin, maternal and paternal education,

maternal employment (Multivariate better

outcomes) high maternal education, Greek,

maternal employment, only child, girl, not

preterm

- Expressive communication: (univariate)

sex, preterm birth, singleton, siblings, hours

per day with mother, maternal origin,

paternal origin, maternal and paternal

education, maternal employment

(Multivariate better outcomes) low maternal

age, high maternal education, Greek,

maternal employment, only child, girl,

increased birth weight, increased hours per

day with mother

- Fine motor: (univariate) sex, preterm,

singleton, ICU, maternal education,

93

Author

(Year)

Study

Design

Study

population

Neurodevelopment


maternal employment (Multivariate better

outcomes) high maternal education, Greek,

singleton, female

- Gross motor: (univariate) preterm,

siblings, ICU, maternal education, paternal

education, maternal employment

(Multivariate better outcomes) only child

- Social-emotional: (univariate) sex,

preterm, singleton, maternal education,

paternal education (Multivariate better

outcomes) medium or high maternal

education, singleton, female

Laucht et

al., 1997141

Prospective

cohort study

A subset of 350

infants were

assessed from the

Mannheim Study

of Risk Children.

- Bayley Scales of

Infant Development,

1st edition at 4.5 years

of age

- Assessed gross

motor development

- Biological risk: term status,

birth weight, medical

complications,

- Psychosocial risk: measure of

unfavorable familial

characteristic (i.e. low

education, crowded living,

parental psychiatric disorder,

parental delinquency, history of

broken home, marital discord,

early parenthood, single-parent

family, unwanted pregnancy,

lack of social support, severe

chronic difficulties, poor coping

skills

- Behavioral and emotional

assessment

- Children with complications of pregnancy

or delivery displayed delayed motor

development at all age periods

- Children suffering from pre- and perinatal

complications also performed more poorly

on the measures of cognitive development at

all age periods

- Poorer motor and cognitive functioning

was shown among children of

disadvantaged families

- Children with multiple (biological and

physiological risks) showed the most

favourable prognosis in all areas of

functioning

- Among the predictors of motor

development, complications during

pregnancy and neonatal period had the

greatest impact

- Low parental education was a significant

predictor of cognitive development delays.

Levantakou

et al.,

2013142

Prospective

cohort study

A subset of 540

mother-child

dyads were

assessed from the

Rhea Cohort

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Breastfeeding: initiation,

duration, use of formula,

complementary food


Depression Scale

- Mothers were more likely to breastfeed

their child longer if they were older, had a

university degree, did not smoke during

pregnancy or after birth

- Longer duration of breastfeeding was also

94

Author

(Year)

Study

Design

Study

population

Neurodevelopment


Study. Women

spoke Greek and

were older than

16 years of age

with no

communication

handicap. Only

singleton

pregnancies

included

- Assessed fine and

gross motor

development

- Parental characteristics:

maternal and paternal age,

education, origin, maternal

working status, marital status,

parental smoking during

pregnancy and postpartum,

- Perinatal and infant

characteristics: sex, type of

delivery, siblings, birth order,

birth weight, head

circumference, gestational age,

preterm birth, NICU, day care

attendance, hours per day with

mother or father, age of

introduction of solid foods

positively associated with paternal age,

paternal high education, paternal non-

smoking during or after pregnancy

- Crude analysis found that breastfeeding

was associated with higher cognitive,

receptive communication and fine motor

scores

- Duration of breastfeeding was positively

associated with higher scores in all

developmental measures except gross motor

in adjusted models

- Children who were breastfed longer than 6

months had higher fine motor scores in

adjusted models

95

Author

(Year)

Study

Design

Study

population

Neurodevelopment


Long et al.,

2016143

Prospective

cohort study

A sample of 33

children were

recruited.

Children

underwent cardiac

surgery in the first

2 months of life,

had no known

chromosomal

abnormalities or

congenital

syndromes, and

their families

spoke English and

lived >100km

outside

Melbourne

metropolitan area.

- Alberta Infants

Motor Scale at 4, 8,

12, and 16 months of

age

- Assessed gross

motor development

- Bruininks-Oseretsky Test of

Motor Proficiency Brief Form,

2nd edition

- Pediatric Clinical Test of

Sensory Interaction

- Range of movement and leg

length

- Bayley Scales of Infant

Development, 3rd edition at 2

years

- Social Risk Index: family

structure, education of the

primary caregiver, occupation,

employment status and income

of primary earner, language

spoken at home and maternal

age at delivery

- Covariates: gestational age,

birth weight, cardiopulmonary

bypass time, respiratory support

time, ICU length of stay, sex,

cyanotic CHD, single or

biventricular circulation, arch

repair, reciprocal or

asymmetrical crawl pattern

- 41% of patients who underwent early

cardiac surgery had below-average motor

proficiency at 5 years of age

Majnemer et

al., 2006144

Prospective

cohort study

A sample of 83 4-

month old and 72

6-month old

infants were

recruited. Infants

were excluded if

they were <38

weeks’ gestation,

their parent did

not speak English

or French, they

had torticollis,

- Alberta Infant

Motor Scale at 4 or 6

months

>Assessed gross

motor development

- Peabody

Developmental Motor

Scales

> Assessed fine

and gross motor

- Sleep position

- Awake position

- Demographics: weight, sex,

parity, breastfeeding, maternal

smoking, parents’ age, education

- Potential confounders: weight

at assessment, parity, parental

age and education, sex and age

at testing

- Prone AIMS score was significantly higher

among infants sleeping in the prone position

at 4 months of age. There was no difference

between the prone and supine group on the

PDMS at 4 months.

- Infants sleeping in the prone position had

higher scores on the prone, supine,

percentile and total score of the AIMS and

higher gross motor score on the PDMS

compared to infants sleeping in the supine

position at 6 months.

- At 15 months of age there were not

96

Author

(Year)

Study

Design

Study

population

Neurodevelopment


prenatal or

perinatal

complications or

attending day care

where positioning

practices less

consistent.

development

- Battelle

Developmental

Inventory at 15

months of age

significant differences between the supine

and prone sleep-position groups on motor

performance or overall developmental

scores

- Infants put to sleep in the prone position

were more likely to spend more time awake

in the prone position and spend less time

being held than those sleeping in the supine

position at 6 months of age.

- At 4 months, mean daily exposure to prone

position when awake, mean exposure to

supported sitting position and parents age

was correlated to AIMS scores

- At 6 months, awake prone time was

correlated with AIMS scores and gross

motor PDMS scores. Gross motor scores

were associated with sitting exposure. In

adjusted models, sleep position consistently

predicted AIMS and PDMS gross motor

scores.

- At 15 months, sleep position continued to

predict motor performance

Majnemer et

al., 2005145

Cross-

sectional

study

A sample of 71 4-

month old and 50

6-month old

infants were

assessed. Infants

were excluded if

they were <38

weeks’ gestation,

their parent did

not speak English

or French, they

had torticollis,

prenatal or

perinatal

complications or

- Alberta Infant

Motor Scale at 4 or 6

months

>Assessed gross

motor development

- Peabody

Developmental Motor

Scales

> Assessed fine

and gross motor

development

- Sleep position

- Awake position

- Demographics: weight, sex,

parity, breastfeeding, maternal

smoking, parents’ age, education

- Potential confounders: weight

at assessment, parity, parental

age and education, sex and age

at testing

- At 4 months of age: AIMS centiles

positively correlated with prone awake time

and negatively correlated with maternal and

paternal age. PDMS fine motor scores

positively correlated with supported sitting

time and age at testing, and negatively

correlated with prone awake time and

parents’ education. Gross motor scores were

positively correlated with age at testing.

- At 6 months of age: AIMS centiles

positively correlated with prone awake time.

PDMS fine motor scores positively

correlated with prone awake time. Gross

motor scores were positively correlated with

prone awake time and supported sitting

97

Author

(Year)

Study

Design

Study

population

Neurodevelopment


attending day care

where positioning

practices less

consistent.

time, and negatively correlated with paternal

age.

McGrath &

Sullivan,

1999146

Prospective

cohort study

A sample of 108

4-year old

children and their

mothers were

enrolled. Mothers

were English-

speaking, older

than 16 years of

age, had no

psychiatric

history and denied

drugs and

substances abuse.

- Riley Motor

Problems Inventory at

4 years of age

> Assessed oral

motor and fine motor

development

- Beery Visual-Motor

Integration Test at 4

years

> Assessed Visual-

Motor development



4 years of age

> Assessed general

motor development

(author argues is a

good indicator of

gross motor

development)

Proximal Measures:

- Maternal Self-Esteem Scale

- Perception of Child Health



Measurement of the

Environment Preschool Version

- Parent/Caregiver

Involvement Scale

- Problem Solving Scale

Distal Measures:

- Family Resource Scale

- Family Support Scale

- Family Functioning Scale

- Life Events Questionnaire

- Hollingshead Four-Factor

Index of Social Status

Child Measures:

- EAS Temperament Survey

of Children: Parental Ratings

- Behavioural Style

Assessment

- Medical Risk Score

- Fine motor development significantly

lower among preterm infants with medical

conditions or neurological compromise than

compared to full-term or healthy preterm

infants.

- Full-term infants scores higher on visual-

motor integration than compared to any

preterm group (healthy preterm, small-for-

gestational age preterms, sick preterms, or

preterms with medical complications or

neurologic compromise.

- The percentage of children with motors

delays was fewest among the full-term

infants (5%-17%)

- Hierarchical multiple linear regressions:

- Oral motor: child measures were the

only significant predictor. Proximal and

distal measures not independently

significant

- Fine motor: Proximal and child

measures significant predictors

- Gross motor: proximal, distal and child

measures were significant predictors

- Visual-motor: proximal and child

98

Author

(Year)

Study

Design

Study

population

Neurodevelopment


measures were significant predictors

McDonald

et al.,

2014147

Prospective

cohort study

A sample of 159

Aboriginal infants

were recruited.

- Griffiths Mental

Development Scales

– Extended Revised

at 1 and 3 years of

age

- Assessed fine and

gross motor

development


Test, 4th edition

- Study factors: sex, suburb of

residence, parity, maternal age,

maternal education, marital

status, mother was in foster care,

primary care giver not mother,

preschool/day care

- Socio-economic Indexes for

Areas

- Kessler-5 depression scale

(primary care giver)

- Bivariate risk factors for GMDS-ER:

maternal age <20 years, low maternal

education, single mother

- Multivariate risk factors for GMDS-ER:

maternal age <20 years, single mother

Michalowicz

et al.,

2011148

Randomized

Control Trial

A sample of 411

women were

recruited from the

Obstetrics and

Periodontal

Therapy Trial.

- Bayley Scales of

Infant Development,

3rd edition at 24-28

months of age

- Assessed fine and

gross motor

development

- Preschool Language Scale, 4th

edition

- Infant characteristics: history

of seizures, trauma, ventilator

use, steroid use, lead and

hematocrit levels

- Family history: history of child

care, parent education, health-

related behaviours, Home

Observation for Measurement of

the Environment (HOME)

Inventory, emotional and verbal

responsiveness of the

mother/primary caregiver,

avoidance of restriction and

punishment, organization of the

physical and temporal

environment, provision of

- Mean cognitive, motor and language

scores did not differ significantly between

treatment and control groups in unadjusted

or adjusted analyses

- Explanatory variables that were significant

in multiple linear regression analysis:

- Cognitive development: Clinic

- Motor development: Clinic, gestational

age at delivery, 5-minute Apgar score, head

circumference <10 percentile, primary

caregiver’s education

- Language: head circumference <10

percentile, HOME inventory

99

Author

(Year)

Study

Design

Study

population

Neurodevelopment


appropriate play material,

maternal involvement with the

child, and variety in daily

stimulation

Miller-

Loncar et

al., 200485

Prospective

cohort study

A subset of 392

cocaine exposed

and 776

unexposed infants

from the Maternal

Lifestyle Study

were assessed.

- NICU Network

Neurobehavioral

Scale (NNNS) at 1

month of age

> Assessed general

motor development

(combined composite

score)

- Posture and Fine

Motor Assessment of

Infants (PFMAI) at 4

months of age

> Assessed

postural and fine

motor development

(combined into

composite score)

- Bayley Scales of

Infant Development,

2nd edition at 12

months of age

> Assessed general

motor development

- Peabody

Developmental Motor

Scales at 18 months

of age

> Assessed general

motor development

- Maternal Inventory of

Substance Abuse (timing and

amount of cocaine, alcohol,

nicotine, and marijuana used

during pregnancy

- Hollingshead Index of Social

Position

- Covariates: SES, birth weight,

race, study site

- Prenatal cocaine exposure was

significantly associated with poorer motor

skills.

- Prenatal cocaine exposure interacted with

age, where infants exposed to cocaine

displayed a faster rate of increase in motor

skills than the comparison group

- Study site, birth weight and heavy tobacco

use was also associated with motor

development

- Heavy prenatal exposure to cocaine was

associated with poorer motor scores

compared to unexposed infants. There was

not a significant difference based on level of

exposure for change over time, however.

100

Author

(Year)

Study

Design

Study

population

Neurodevelopment


(combined into

composite score)

Nelson et

al., 200490

Prospective

cohort study

A sample of 143

2-year old and

274 4-year old

children were

enrolled.

- Bayley Scales of

Infant Development,


of age

>Assessed general

motor development

- Peabody

Developmental Motor


age

> Assessed fine

and gross motor

- Cocaine, marijuana, tobacco,

alcohol exposure


Test-Revised

- Brief Symptom

Inventory/Global severity Index

- Maternal characteristics: race,

age, SES, gravida, parity,

number of prenatal care visits

- Infant Measures: birth

outcomes, Apgar scores, Hobel

Neonatal Risk Index

- Hematologic assessment:

hemoglobin, mean corpuscular

volume, transferrin saturation,

serum ferritin, lead, iron status

- Environmental measures:

Home Observation of the

Environment (HOME) Inventory

Neurodevelopment: Wechsler

Preschool and Primary Scales of

Intelligence

- Correlations with motor development:

- 2-year psychomotor: ethnicity, parity,

maternal education, sex

- 4-year gross motor: parity, maternal IQ

(PPVT-R), birth weight, head

circumference, Hobel risk score, gestational

age

- 4-year fine motor: parity, maternal

education, sex, nonmaternal care

- Full Scale IQ was predicted by iron

deficiency anemia and lead levels

- Verbal IQ was predicted by HOME scores

- Performance IQ was predicted by maternal

IQ, cocaine exposure and lead

Nervick et

al., 2011149

Cross-

sectional

study

A convenience

sample of 50

children between

3-5 years of age

were enrolled.

Children were

typically

developing health,

enrolled in day

care and free from

medical,

orthopedic or

neurological

- Peabody

Developmental Motor

Scales, 2nd edition at

3-5 years of age

- Assessed fine and

gross motor

development

- Anthropometric tests: child’s

height, weight, BMI

- Significant correlation between BMI sets

and gross motor quotient

- Stepwise hierarchical regression analysis

found that neither gender nor age nor BMI

sets made a significant contribution to the

linear regression model

101

Author

(Year)

Study

Design

Study

population

Neurodevelopment


conditions that

could affect

performance in

gross motor skills

Oddy et al.,

2011150

Prospective

cohort study

A sample of 2868

children involved

in the Western

Australian

Pregnancy Cohort

(Raine) Study.

- Infant/Child

Monitoring

Questionnaire (a.k.a.

Ages and Stages

Questionnaire) at 1, 2

and 3 years of age

- Assessed fine and

gross motor

development

- Questionnaire collecting

information on parental

sociodemographic factors

(housing, family structure,

employment and income),

family functioning,

neurodevelopment, behaviour

and history of illnesses, injuries

and admissions to hospital

- Predictor measure:

breastfeeding

- Confounding factors: maternal

age, education, smoking during

pregnancy, biological father

presence, family income, total

number of stressful life events

experienced during pregnancy,

child’s Apgar scores, gestational

age, sex

- Infants who had breastfed for >4 months

had significantly higher scores on fine

motor and communication development at

1, 2 and 3 years compared to infants who

breastfed for <4 months. Moreover, infants

who had breastfed for >4 months also had

significantly higher scores on adaptability at

1 and 2 years compared to infants who

breastfed for <4 months.

- The results of multinomial logistic

regression analyses showed that

breastfeeding for <4 months significantly

increased the risk for two or more atypical

scores across all domains over the 3 years of

the study except for gross motor skills.

Piteo et al.,

2012151

Prospective

cohort study

A sample of 360

infants were

recruited from the

control group of

the DOMInO

trial. Women

were given

vegetable oil

capsules without

DHA.

- Bayley Scales of

Infant Development,

3rd edition at 18

months of age

- Assessed fine and

gross motor

development


Depression Scale (at 6 weeks

and 6 months postpartum)

- Baseline characteristics:

maternal age, medical diagnosis

of previous or current

depression, current treatment for

depression, social support

(Maternal Social Support Index),

education and occupation


(HSQ)

- Adjusted models controlled

for: preterm birth, maternal

- No significant differences between

maternal depression and child cognitive,

language or motor development at 18

months of age in unadjusted or adjusted

analysis

- Home environment was a significant

predictor of each developmental outcomes

after adjusting for demographic variables

- Maternal occupation, maternal secondary

education, maternal further education, and

infant feeding at 6 months of age were

significant predictors of cognitive

development in adjusted models

- No demographic variables had a

102

Author

(Year)

Study

Design

Study

population

Neurodevelopment


occupation, maternal secondary

education, maternal further

education, history of depression,

home environment, maternal

social support, and infant

feeding at 6 weeks and 6 months

of age

significant effect on motor development in

either adjusted or unadjusted analyses

Richardson

et al.,

1995152

Prospective

cohort study

A sample of 829

women were

enrolled. Women

were selected

from two ongoing

cohort studies: a

study on alcohol

consumption

during pregnancy

and a study on

marijuana

consumption

during pregnancy.

- Bayley Scales of

Infant Development,

3rd edition at 9 and 19

months of age

- Assessed fine and

gross motor

development

- Alcohol and marijuana

exposure

- Tobacco and other drug use

during pregnancy

- Gestational age,

- Maternal medical history,

pregnancy (anemia, maternal

infections, hypertension,

abnormal bleeding), labour

(precipitous labour, induction,

Pitocin augmentation and

premature labour) and delivery

conditions (anesthesia,

meconium stained fluid, nuchal

cord, cesarean section and

forceps delivery)

- PROCESS Scale

- HOME Inventory

- In regression analyses, prenatal alcohol

and tobacco use did not predict

psychomotor or mental development at 9

months

- Third trimester marijuana use predicted

lower mental development at 9 months

- At 19 months of age, prenatal alcohol,

marijuana or tobacco use did not predict

psychomotor or mental development scores

- Variance in mental development was

explained by number of toys in the house,

developmental stimulation, sex, race, age

examiner, SES, psychosocial and family

configuration

- Current tobacco use was a predictor of

mental development at 19 months

- ANCOVA analysis of differing duration of

exposure to alcohol or marijuana did not

find any significant difference in mental or

motor development

- Infants exposed to one or more packs of

cigarettes per day during pregnancy

exhibited significantly lower mental

development scores than offsprings of non-

smokers

- Adjusted analysis for duration/degree of

exposure:

- No significant difference in

development scores between differing

degrees of alcohol exposure

103

Author

(Year)

Study

Design

Study

population

Neurodevelopment


- Significantly lower scores were

exhibited by infants of mothers smoking 1

or more joints per during the third trimester,

compared to infants of nonsmokers or

moderated marijuana users

- Infants exposed to one or more packs

of cigarettes per day during the first

trimester exhibited significantly lower

mental development scores than offsprings’

of non-smokers

Saraiva et

al., 2013153

Cross-

sectional

study

A sample of 367

children were

enrolled in the

study. They were

divided into three

age groups: 3-

year-olds (122),

4-year-olds (130)

and 5-year-olds

(115). Children

had no

intellectual,

physical or

emotional

disabilities.

- Peabody

Developmental Motor

Scales, 2nd edition

- Assessed fine and

gross motor

development

- Child characteristics: height,

weight, BMI (all converted to

age-appropriate z-scores

according to WHO Child

Growth Standards

-

- Sex differences: Boys showed higher

scores on object manipulation at 3, 4 and 5

years, whereas girls showed higher scores

on grasping and visual-motor integration at

3 and 4 years of age

- Grasping: Age and sex predictor variables

at 3 and 4 years. Height for age predictor at

5 years.

- Visual-motor integration: age a predictor

at 3, 4 and 5 years. Sex a predictor at 3

years.

- Stationary: age a predictor at 3, 4 and 5

years. Height-for-age a predictor at 3 years,

and BMI-for-age a predictor at 5 years.

- Locomotion: Age a predictor at 3 and 4

years

- Object manipulation: age and sex a

predictor at 3, 4 and 5 years. Weight-for-age

a predictor at 4 years.

Scher et al.,

200899

Prospective

cohort study

A convenience

sample of 142

infants were

assessed. Infants

were participating

in the Training

and Outcomes for

Early

- Harris Infant

Neuromotor Test

(HINT) at 4-6 and 10

12 months of age

- Assessed general

motor development

***NOTE: lower


- Infant Sleep Questionnaire

- HINT scores were not associated with

scores from the Infant Sleep Questionnaire

- Parental perception of child’s sleep

difficulty was associated with child

neurodevelopment at 10-12 months of age,

but not at 4-6 months of age

- Severity of sleep difficulties significantly

decreased with age in the “no-risk group”

104

Author

(Year)

Study

Design

Study

population

Neurodevelopment


Identification of

Infants with

Neuromotor

Delays. Infants

were born at term

(>37 weeks’

gestation),

weighed >2500

grams, and had no

postnatal infant

health problems

or congenital

anomalies.

development***

- Alberta Infant

Motor Scale 4-6 and

10 12 months of age

- Assessed general

motor development

- Ages and Stages

Questionnaire at 4-6

and 10 12 months of

age

- Assessed fine

and gross motor

development

and the “low risk group”, but not in the

“high risk group”

- In the low-risk group, sleep difficulties

decreased with age, whereas in the high-risk

group, sleep disruption increased over time

Smith et al.,

2011154

Prospective

cohort study

A sample of 412

mother-infant

dyads were

recruited into the

IDEAL Study.

204 infants were

exposed to

methamphetamine

prenatally, while

208 infants were

non-exposed.

- Peabody

Developmental Motor

Scale at 12 and 36

months of age

>Assessed gross

and fine motor

development

- Bayley Scales of

Infant Development,

2nd edition at 12, 24,

36 months of age

- Assessed general

motor development

- Methamphetamine exposure:

self-report and meconium screen

- Lifestyle Interview: number of

prenatal visits, age, education,

occupation, race, marital status,

type of insurance, SES

(Hollingshead Index), licit and

illicit drug use, alcohol, tobacco

and marijuana

- Substance Use Inventory


Test, 3rd edition


Measurement of the

Environment (HOME) Inventory

- Methamphetamine exposure was

associated with lower scores on the grasping

subtest at 1 year, but not at 3 years.

Moreover, heavy methamphetamine use was

associated with lower grasp scores than

some methamphetamine exposure or no

exposure

- No significant difference between

methamphetamine exposure of mental or

psychomotor development were found

- After adjusting for birth weight, prenatal

drug exposure and SES, grasping scores

were lower in children with prenatal

methamphetamine exposure

- Low SES was associated with low fine

motor development

- No significant difference between

methamphetamine exposure and fine or

gross motor development

- Maternal IQ and quality of home were

associated with mental development, but not

motor development

105

Author

(Year)

Study

Design

Study

population

Neurodevelopment


- Both motor and mental development was

lower among boys than girls

Sommerfelt

et al.,

1996155

Cross-

sectional

study

A sample of 144

5-year old low-

birth weight

children were

compared to 163

normal birth

weight children.

- Peabody

Developmental Motor


age

- Assessed fine and

gross motor

development

- Feeding practices

- Intrauterine growth restrictions

- Infant Characteristics:


head circumference, birth length

- Cranial ultrasound: cerebral

hemorrhage

- Parental factors: parental

education, total family income,

maternal smoking, single-parent

family status

- Abnormal balance scores, presences of

motor problems and abnormal minor

neurology scores were significantly more

common in low-birth weight boy than

normal birth weight

- Abnormal eye-hand coordination and leg

neurology scores were significantly more

common in low birth weight girls

- For low-birth weight boys, there was an

increased risk of abnormal balance scores

and of having a motor problem when the

infant received predominantly formula

compared to breastmilk or breastmilk and

formula

- For the low-birth weight girls, none of the

pre-, peri- or post-natal factors were

predictive of abnormal scores on the eye-

hand coordination or leg neurology scales

Tirosh et al.,

1991156

Cross-

sectional

study

A sample of 59

children with no

known

neurological,

genetic or

cognitive

problems were

evaluated. Among

the sample, 20

infants had joint

hypermobility and

delayed motor

development, 19

infants had joint

hypermobility and

normal

development, 20

- Hoskins-Squires test

for gross motor and

reflex development at

54-60 months of age

> Assessed gross

motor development

- Bruininks-Oseretsky

pegboard test/block

tower/Beery-

Buktenica visual-

motor integration test

at 54-60 months

> Assessed fine

motor development

- Parent perception of motor

proficiency

- Conner’s parent rating scale

- Prevalence of gross motor delays at 5

years of age among infants had joint

hypermobility and delayed motor

development were higher than in the other

two groups

- Children who presented with joint

hypermobility and motor delays at 18

months were significantly more likely to

present the same association when they

reached 5 years of age

- Infants had joint hypermobility and

delayed motor development showed

significant disadvantages in the pegboard

test

- No differences were found in the visual-

motor integration test

- No differences were found in perceived

106

Author

(Year)

Study

Design

Study

population

Neurodevelopment


were normal

controls.

behaviour by the Conner’s rating scale

Torsvik et

al., 2015157

Prospective

cohort study

A sample of 97

healthy infants

and their mothers

were

consecutively

recruited.

- Alberta Infant

Motor Scale at 6

months of age

> Assessed gross

motor development

- Ages and Stages

Questionnaire at 6

months of age

> Assessed fine

and gross motor

development

- Gestational age was based on

ultrasonography

- Maternal and infant nutrition

and vitamin supplementation

- Blood samples collected from

infant and mother (assessed

cobalamin)

- Breastfeeding/feeding practices

- Cobalamin intervention

- Strongest determinant of infant vitamin B

status at 6 months was duration (months) of

exclusive breastfeeding, where those

breastfed

> Vitamin B status at 6 months showed a

linear, inverse relationship with duration of

exclusive breastfeeding

- Formula fed infants had a significantly

higher median AIMS score than breastfed

infants

- Duration of exclusive breastfeeding was a

significant negative predictor of AIMS score

in a multiple linear regression model

adjusted for gender, SGA, infant weight,

maternal education, and folate and iron

supplementation

- The breastfed infants had significantly

lower median gross motor scores

- No significant difference was observed for

communication, personal-social functioning

and problem solving skills

Tsuchiya et

al., 2012158

Prospective

cohort study

A subset of 742

infants enrolled in

the Hamamatsu

Birth Cohort were

assessed.

- Mullen Scales of

Early Learning at 6,

10 and 14 months

- Assessed gross

motor development

- Season of birth: Winter

(December, January, February),

Spring (March, April, May),

Summer (June, July, August),

Fall (September, October,

November)

- Demographic information:

maternal age, paternal age,

parity, household annual income

- Perinatal variables: gestational

age, birth weight, date and time

of birth

- Predicted gross motor scores at 6 months

of age peaked among March- and April-

born infants, and was lowest among

September- and October-born infants

- Gross motor scores peaked among

February-born infants at 10 months of age

- The difference in gross motor scores

between 6 and 10 months of development

peaked among December- and January-born

infants

- The difference in gross motor scores

between 10 and 14 months of development

107

Author

(Year)

Study

Design

Study

population

Neurodevelopment


- Breastfeeding status at

examinations

peaked among July- and August-born

infants

Veiby et al.,

2013159

Prospective

cohort study

A subset of 78744

mother-infant

dyads were

assessed from the

Norwegian

Mother and Child

Cohort Study.

- Ages and Stages

Questionnaire at 6


- Assessed fine and

gross motor

development

- Parental epilepsy

- Antiepileptic drug exposure

(monotherapy and polytherapy)

- Breastfeeding practices

- Gestational age, birth weight,

congenital malformations,

- Adjusted models for maternal

age, parity, education, folate

supplementation, smoking,

depression/anxiety,

breastfeeding, child

malformations

- Children exposed to antiepileptic drugs

had an increased risk of having lower fine

motor scores than unexposed children

- Children of mothers treated with the

polytherapy had an increased risk of poor

fine motor development compared to

unexposed children. There was no increased

risk among children exposed to the

monotherapy compared to unexposed

children

- Children of fathers with epilepsy did not

exhibit significant delays across any of the

developmental outcomes

- Continuous breastfeeding during the first

6-months was associated with a tendency

toward improved outcome for all

developmental outcomes, regardless of

antiepileptic exposure

Velikos et

al., 2015160

Prospective

cohort study

A sample of 120

of premature

infants.

- Bayley Scales of

Infant Development,

3rd edition at 12

months of age

- Assessed fine and

gross motor

development

- Demographic information:


gender, premature rupture of

membranes, antenatal steroids,

mode of delivery, small-for-

gestational-age

- Medical interventions:

surfactant administration,

mechanical ventilation, duration

of oxygen therapy, total

parenteral nutrition, number of

blood transfusions

- Prematurity complications:

patent ductus arteriosus, sepsis,


intraventricular hemorrhage,

- Fine motor development: (Bivariate

analysis) – associations with gender,

abnormal head ultrasound, total parenteral

nutrition, small-for-gestational age

(multivariable analysis) - associations with

gender, abnormal head ultrasound, small-

for-gestational age

- Gross motor development: (Bivariate

analysis) – associations with abnormal head

ultrasound, duration of oxygen therapy,

blood transfusions, invasive mechanical

ventilation; (multivariable analysis) –

associations with duration of oxygen

therapy

108

Author

(Year)

Study

Design

Study

population

Neurodevelopment


bronchopulmonary dysplasia,

retinopathy of prematurity,

cystic periventricular

leukomalacia

Wouldes et

al., 2014118

Prospective

cohort study

A subset of 103

methamphetamine

exposed infants

and 107 non-

exposed infants

were assessed

from the New

Zealand Infant

Development,

Environment and

Lifestyle study.

- Bayley Scales of

Infant Development,

2nd edition at 1,2 and

3 years of age

> Assessed general

motor development

- Peabody

Developmental Motor

Scale, 2nd edition at 1

and 3 years of age

>Assessed fine

and gross motor

development

- Substance use inventory:

quantity and frequency of

prenatal drug use

- Current household structure,

SES, quality of home

environment


Test, 3rd edition

- Covariates: gender, birth

weight, ethnicity, drug use, SES

- No effects of methamphetamine exposure

on gross or fine motor development at 1

year of age

- At 3 years of age, gross motor

development was significantly lower among

infants exposed to prenatal

methamphetamine compared to non-

exposed infants

- At 1 and 2 years of age, methamphetamine

exposed was associated with lower

psychomotor scores compared to non-

exposed infants

-

Wylie et al.,

2015161

Prospective

cohort study

A subset of 4901

mother-infant

pairs were

assessed from the

Upstate KIDS

study.

- Six gross motor

milestones: sitting

without support,

standing with

assistance, hands-

and-knees crawling,

walking with

assistance, standing

alone, walking alone

- Used WHO 90th

centile’s

- Maternal BMI, paternal height

and weight, obstetrical

outcomes, sociodemographic

characteristics, SES, medical

insurance, plurality

- Smoking status and alcohol use

before and during pregnancy

- Gestational age, small-for-

gestational age, sex, birth weight

- Infants of mothers who were obese prior to

pregnancy were found to have a

significantly lower risk of achieving the

motor milestones of sitting without support

and crawling on hands-and-knees (achieved

milestones later)

- Children born to obese mothers had higher

odds of delay in walking compared to

children born to mothers with normal BMI

- Infants born to mothers with less than a

high school education or its equivalent were

slower to achieve standing with assistance,

walking with assistance, and walking alone

compared to infants with mothers with an

advanced degree

Yeung et al.,

2016162

Prospective

cohort study

A subset of 4824

mother-child

dyads were

assessed from the

- Ages and Stages

Questionnaire at 4, 6,

8, 12, 18, 24, 30 and

36 months of age

- Infertility Treatment Exposure

- Covariates: maternal and

paternal age, insurance status,

plurality, previous live birth,

- No statistically significant differences

were observed for any of the five

developmental domains assessed when

adjusting for birth weight and plurality

109

Author

(Year)

Study

Design

Study

population

Neurodevelopment


Upstate KIDS

study.

- Assessed fine and

gross motor

development

pre-pregnancy BMI, paternal

BMI, marital status, ethnicity,

education, smoking and alcohol

use during pregnancy

- Frequency of any disability did not differ

by infertility treatment exposure

110

2.2.2.1 Sociodemographic factors

Many of the previously described associations between socio-demographic factors and

general motor development have also been investigated with respect to fine and gross motor

development. For example, in their analysis of a sample of 356 children from the IDEAL study

in the US, Smith et al. found that SES, classified using the Hollingshead Four-Factor Index of

Socioeconomic Status, influenced fine motor development, but not gross motor development154.

Similar results were also found in Nelson et al.’s study, when marital status was used as a proxy

measure for SES90.

Other proxy measures for SES, such as maternal education have been shown to exhibit

different associations with fine and gross motor development. For instance, Koutra et al.

suggested that twins and children of mothers with low educational attainment exhibited lower

fine motor developmental scores compared with children of educated mothers140. Contrary to the

results by Koudra et al.140, however, Nelson et al., reported that maternal education was neither

associated with fine nor gross motor development90. Furthermore, Nelson et al. found that lower

maternal IQ, measured using the Peabody Picture Vocabulary Test-Revised, was associated with

poorer gross motor development.

The effect of parental age and a child’s sex revealed similar results to the data described

in the assessment of general motor development. Higher maternal120 and paternal120,134,138 age

were associated with poorer fine and gross motor development. Moreover, males exhibited lower

scores in fine motor development90,138,140. Gross motor development, however, did not differ

between males and females90,128,140.

Sociodemographic factors were shown to influence fine and gross motor

development90,120,130,138,140,154 in a similar pattern as general motor development. Given the

111

difference in the influence of sex on fine and gross motor development, however, updating

previous recommendations for controlling for sex when assessing factors influencing motor

development may be required when analyzing contemporary data.

2.2.2.2 Maternal health factors

Compared with studies interested in general motor development, few studies have

separated the influence of maternal physical health on child fine or gross motor development. Of

the limited number of studies, Wehby et al. investigated the association between folic acid

supplementation during pregnancy and fine and gross motor outcomes at 3 years of age 117. In

their analysis, they reported an association between folic acid supplementation during pregnancy

and increased gross motor scores during their follow-up of 6,774, singleton pregnancies.

Conversely, their analysis also revealed that calcium supplementation during pregnancy was

associated with lower gross motor development scores. No associations were found for fine

motor development.

Contrary to maternal physical health, the effect of maternal mental health on fine and

gross motor development has been well investigated. For example, in their aforementioned

study, Handal et al. reported that depression prior to pregnancy was associated with fine and

gross motor development delays in their analysis of the effects of selective serotonin reuptake

inhibitors on motor development of Norwegian children134. It was also reported, however, that

anxiety before pregnancy, and depression or anxiety during pregnancy were not associated with

fine or gross motor development in three year old children. Finally, Handal et al.’s analysis also

revealed that treatment with selective serotonin re-uptake inhibitors during pregnancy was

112

associated with delays in both fine and gross motor development in children of three years of

age.

Other drug exposures during pregnancy have also been investigated, with conflicting

results90,120-122,127,129,130,133,134,154. To understand motor development of infants prenatally exposed

to cocaine, Arendt et al. recruited infants into a 2-year longitudinal follow-up study120 where

information on maternal drug use was collected using the Maternal Postpartum Drug Interview.

Assessment of 98 cocaine-exposed and 101 unexposed infants revealed that cocaine exposure in

the first trimester of pregnancy was associated with poorer fine and gross motor development at

2 years of age. Furthermore, Arendt et al. also described that alcohol consumption in the month

prior to pregnancy or during the first trimester was also significantly associated with delayed

gross motor development. Marijuana exposure of any frequency at any point during pregnancy,

however, was not associated with motor development.

Similar results were also obtained in Handal et al. and Smith et al. analyses. Handal et al.

described that maternal self-report of cigarette consumption was associated with both fine and

gross motor development delays134. Additionally, Smith et al. found that children of the 204

pregnant women whose methamphetamine exposure was validated using meconium screening

had an increased risk of poor scores on a grasping subtest of the Peabody Developmental Motor

Scales (grasping score among exposed: 9.38, SD:1.66; scores among non-exposed: 10.51,

SD:1.97; p=0.024)154. Fine and gross motor development subscales, however, were not

associated with methamphetamine consumption during pregnancy.

Conflicting results for the consumption of alcohol, cigarettes, marijuana and cocaine,

however, are presented by Nelson et al90. In their analysis, maternal self-report of cocaine,

113

marijuana, tobacco and alcohol consumption was not associated with fine or gross motor

development.

The best quality of evidence suggest that folic acid supplementation, depression, and

prenatal drug use are associated with fine and gross motor development. Together, these studies

suggest that maternal physical and mental health must be considered when assessing the child’s

risk of later developmental delays.

2.2.2.3 Pregnancy and birth outcome factors

Similar to the analysis of birth outcomes and general motor development, studies

investigating the influence of birth outcomes on fine and gross motor development have largely

focused on gestational age and birth weight120,122,123,125,127,129,130,131,133,135-139,142,143,150,155,157,158.

Using data from a prospective cohort study of 10,748 singleton Irish infants Cruise et al.

described that low gestational age (25-26 weeks gestation: OR:2.06, 95%CI: 1.60-2.65; 37-41

weeks gestation: reference; 42-46 weeks gestation: OR:0.95, 95% CI:0.79-1.15) and birth weight

(<2500g: OR:1.72, 95%CI:1.28-2.31; 2500-3000g: OR:1.18, 95% CI:0.99-1.41; 3001-3500g:

reference; 3501-4000g: OR:0.85, 95% CI:0.74-0.97; >4000g: OR: 0.94, 95% CI:0.79-1.12) were

shown to be significantly associated with delays in gross motor development125. Fine motor

development, was also shown to be significantly associated with gestational age (25-26 weeks

gestation: OR:1.86, 95%CI: 1.40-2.49; 37-41 weeks gestation: reference; 42-46 weeks gestation:

OR:0.90, 95% CI:0.72-1.13) but not birth weight(<2500g: OR:1.34, 95% CI:0.96-1.88; 2500-

3000g: OR:0.99, 95% CI:0.80-1.22; 3001-3500g: reference; 3501-4000g: OR:0.90, 95% CI:0.76-

1.06; >4000g: OR: 0.81, 95% CI:0.65-1.02)53.

114

The literature investigating the effect of birth outcomes on fine and gross motor

development is limited. Though the effects of gestational age and birth weight53 are well

supported, few additional factors have been directly investigated.

2.2.2.4 Child health factors

Though many childhood health conditions may affect motor development, few have been

investigated for their influence on fine or gross motor development. Among the few studies

published in the literature, Fetters et al. investigated motor development in very-low-birth-

weight infants with and without white matter disease67. Thirty preterm participants with white

matter disease, 21 preterm infants without white matter disease and 21 term infants were

recruited. Their analysis of these 72 infants revealed that gross motor development was

significantly impaired among children with white matter disease.

Joint hypermobility has also been examined for its influence on fine and gross motor

development. In 1991, a longitudinal study examined the motor development of 59 infants at 18

months. Tirosh et al. compared fine and gross motor performance of 20 infants with joint

hypermobility and gross motor delays, 19 infants with joint hypermobility and no gross motor

delays and 20 normal controls124. In their follow-up, fine and gross motor development at 5 years

of age was significantly delayed in the group of children exhibiting both joint hypermobility and

gross motor delays at 18 months of age. Moreover, 65% of individuals exhibiting delays at 18

months of age also exhibited delays at 5 years. The prevalence of gross motor delays among

children exhibiting both joint hypermobility and gross motor delays at 18 months of age (65%)

was significantly higher than the other two groups (joint hypermobility and no gross motor

115

delays: 26.3%, normal: 20%). The low sample size of this study, however, warrants further

investigation regarding the persistence of gross motor delays between 18-60 months.

2.2.2.5 Environmental factors

In addition to the previously described factors influencing general motor development,

such as the infant’s sleep position144,145 and parity90,134,138-140,144,145,158, studies have also

investigated the effects of parental psychological distress (PPD) and intimate partner violence

(IPV) on fine and gross motor development68. In a recent cross-sectional study of 16,595

children, Gilbert et al. described that children exposed to both PPD and IPV had 3.0 (95% CI:

1.8-5.0) times the odds of delayed gross motor development of those unexposed68. Simultaneous

exposure to both PPD and IPV, however, did not significantly affect fine motor development.

When Gilbert et al. examined children just exposed to PPD, however, both fine and gross motor

development were significantly delayed compared with those unexposed (fine motor: OR:1.6,

95% CI: 1.3-2.0; gross motor: OR:1.6, 95% CI:1.4-1.8). Furthermore, in a cross-sectional study

by Hanson et al. examining the development of 176 children involved with child welfare,

children having experienced medical neglect and parental substance abuse had lower gross motor

quotients compared with other reasons for welfare involvement.

Lastly, strong evidence is reported for the association between breastfeeding and motor

development. In their prospective cohort study of 540 Greek mother-child dyads, Levantakou et

al. found that longer duration of breastfeeding was associated with higher fine motor scores on

the subscales in the Bayley Scales of Infant Development at 18 months of age (per month of

breastfeeding: =0.29, 95% CI: 0.02-0.56, p=0.034)142. Breastfeeding duration, however, was

not associated with gross motor development. It was also reported that children who breastfed

116

longer than 6 months scored higher on the fine motor subscale compared with those

breastfeeding for less than 6 months. Similar results were also reported by Oddy et al. where

1451 infants who had breastfed for >4 months had significantly higher scores on fine motor and

communication development at 1, 2 and 3 years compared with 869 infants who breastfed for <4

months150.

In sum, strong evidence has been presented for the association between parity90,134,138-

140,144,145,158, psychological distress or violence68 and fine and gross motor development. Further

research is required to understand factors such as community engagement, physical activity, time

spent watching television, and the effects of child care during early child development.

2.3 Discussion

2.2.1 Critical Appraisal of the Current Body of Knowledge

The literature investigating factors associated with general, fine and gross motor

development is extensive. Associations between socio-demographic, maternal health, pregnancy

and birth outcome, child health, and child environmental factors, and child motor development

are supported by numerous methodologically robust studies. Among these cohort studies,

standardized tools were generally employed to assess child neurodevelopment, and the tools

selected had typically been validated for the study population. Moreover, cohort studies were

largely conducted prospectively, reducing the possibility of selection and recall bias. Limitations

within the literature, however, do exist and include the underrepresentation of minorities and

higher-order births, the potential for misclassification of exposure variables and a lack of

Canadian perspectives.

117

As previously described in the exclusion criteria, the scope of this review included

studies conducted in high income countries with 30 or more participants. Given these criteria,

studies were predominantly cohort studies with large sample sizes. These cohort studies,

however, typically underrepresented groups such as minorities or women with higher-order

pregnancies. Few cohort studies had exclusively investigated the motor development of minority

children72,77,95,108,117,138,147,161. This is a limitation of the literature as ethnicity and immigrant

status both influence motor development59,69,138. Moreover, ethnicity has been shown to modify

the effect of various factors on gross and fine motor development117. For example, Wehby et al.

found that folic acid supplementation was associated with increased gross motor development

with a more pronounced effect among African-American children117. Given these differences in

both developmental patterns and ethnicity-specific effects of factors on motor development,

future research must increase the inclusion of minorities in studies examining motor

development.

In addition to minorities, higher-order pregnancies are also underrepresented in the

literature. Concerns regarding the inclusion of high-order pregnancies are due to the increased

likelihood of infants of multiple pregnancies exhibiting congenital anomalies or other childhood

conditions that may be associated with motor development186. Moreover, twins have an increased

risk of preterm delivery, which has also been associated with poor motor development1,52,56,61-

63,65,67,70,71,73-75,78,82,86,89,92,96,106,107. As such, future cohort studies must include children of higher-

order pregnancies to further understand factors influencing motor development of infants from

multiple birth pregnancies.

Despite the underrepresentation of minorities and higher-order pregnancies, other factors

were well distributed. For example, since Touwen’s description of sex differences in motor

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development assessed by screening tools187, it is common for studies to have equal representation

of both males and females, a characteristic apparent in the presented literature.

The literature in this review also included studies that involved measures of exposure

prone to misclassification bias. For example, studies examining the effect of sleep position on

motor development between the ages of 1-21 months, measured infant sleep position based on

parent reports of the position they laid their child to sleep in67,124,144,145. These studies assumed

that infants’ sleep position did not change throughout the night or as the child aged188. This

assumption may lead to misclassification of the child’s sleep position as most children develop

the capacity to adjust their sleeping position over the age range involved in the studies’

assessments. As such, the position a parent put their child to sleep in may not accurately reflect

the position the child slept most of the night in, thereby leading to misclassification bias.

A similar potential for misclassification is also observed in studies investigating prenatal

exposure to alcohol, tobacco and illicit drug use during pregnancy. In these investigations,

studies typically measured maternal substance use via self-report. To validate self-reports, some

studies assessed urinary128, salivary90 or meconium82,95,154 levels of drug metabolites; however,

this practice was infrequent. Among studies failing to validate self-report of substance use during

pregnancy, misclassification may occur due to maternal recall or reporting bias.

Lastly, few Canadian studies were included in this literature

review49,68,69,89,94,102,119,127,135,143-145. Given the distinct differences between the Canadian and

American health care systems, the at-risk profile for motor development delays may be different

for children of these North American countries. As described above, there is substantial

evidence to suggest that maternal51,57,58,60,68,71,74,77,93,95,103-105,147,150 and child73,78,89,91,107 health

factors influence motor development. It is possible that reduced health care accessibility may

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exacerbate the influence of health risks on motor development. Moreover, differences in

environmental exposure, availability of community resources or medical practices surrounding

pregnancy and birth outcomes may also influence motor development differently between both

countries. As such, future research is required to simultaneously assess the influence of identified

risk and protective factors for motor development among Canadian children.

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CHAPTER 3: METHODS

3.1 Study Design

This study is a secondary analysis of data from The All Our Families Study (AOF), a

prospective community-based pregnancy cohort situated in Calgary, Alberta, Canada (n=3388)48.

3.2 The All Our Families Study

The All Our Families (AOF) study was designed to examine the health outcomes of

mothers and their children during and after pregnancy, as well as throughout the child’s

development48. To do so, women were recruited through primary and prenatal care offices and

Calgary Laboratory Services using posters and word of mouth, from May 2008 to December

2010. To be eligible, women must have been at least 18 years of age and less than 25 weeks’

gestation at enrolment, receiving prenatal care in Calgary, and able to complete the study

questionnaires in English. All eligible women were invited to participate in the study. Once

recruited, participants completed questionnaires in the perinatal and early childhood period.

Using unique identifiers, the questionnaire data were linked to electronic medical records for

labour and delivery data. These records enabled validation of self-report data and provided

additional pertinent details surrounding pregnancy complications and birth outcomes.

In total, 3,388 participants were enrolled in the AOF cohort. Of the women in the study,

76% were less than 35 years of age at the time of delivery (mean=31.2 years, S.D.=4.4), 79%

were Caucasian, 78% were born in Canada, 89% had at least some post-secondary education,

94% were married or in a common-law relationship and 69% reported an annual household

income greater than $80,000 (median income in Calgary $88,000)48. When compared with data

collected by the Maternity Experiences Survey (MES), a project implemented by the Public

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Health Agency of Canada, AOF participants were generally representative of pregnant women

and families in Canada with a few exceptions (Table 4). Compared with the MES, the AOF study

reported a greater proportion of women: 1) attending prenatal or childbirth educational classes,

2) over the age of 35, and 3) with an annual income greater than $40,000. Finally, the proportion

of women reporting having experienced postpartum depression was lower in the AOF study;

however, the proportion of women reporting postpartum health as very good/excellent was also

lower.

Table 4: Comparison of AOF participants to MESa participants (Adapted from

McDonald et al., 201348)

Characteristics AOF % Alberta % Canada %

Demographic Characteristics

> 35 years 24.1 15.6 17.5

Postsecondary completed 76.3 69.5 72.1

>$40K 92.3 77.8 72.6

Primiparousb 48.9 46.0 44.7

Pre-pregnancy BMI (mean) 24.3 24.4 24.4

Pregnancy Characteristicsc

Number of prenatal care visits (mean) 12.8 13.0 12.9

Gestational age at first prenatal care

visit (mean) 9.1 7.2 7.5

Initiated prenatal care in first trimester

(<14 weeks) 93.1 94.9 94.9

First ultrasound <18weeks 85.6 63.4 66.8

Attended prenatal or childbirth

education classes 41.2 33.4 32.7

Satisfied with timing of pregnancy 52.6 50.9 49.5

Feeling happyd upon realization of

pregnancy 87.0 90.8 93.0

Intended to breastfeed 96.2 93.8 90.0

Delivery and postpartum experiences

Preterm birth rate 7.3 6.3 6.2

Caesarean section delivery 24.5 27.3 26.3

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Short length of maternal stay in hospital

Vaginal delivery (<2 days) 66.8 60.7 33.6

Caesarean section (<4 days) 79.9 59.1 53.0

Initiated breastfeeding 97.8 94.6 90.3

Scoring ≥13 on Edinburgh Postnatal

Depression Scale 5.1 6.5 7.5

Rated postpartum health as very good

or excellent 53.9 73.6 72.5

Postpartum BMI (mean) 25.6 25.5 25.4

a Maternity Experiences Survey 2006-2007; comparisons involve singletons only b according to status at birth c assessed during postpartum in MES (retrospective recall); assessed during pregnancy in

AOF d “happy” derived from collapsing responses of “somewhat happy” and “very happy”

3.3 Data Collection

Participants in the AOF study completed three questionnaires in the perinatal period (22-

24 weeks gestation: Q1; 32-36 weeks gestation: Q2; 4 months postpartum: Q3) and three

questionnaires in the early childhood period (12 months postpartum: Q4; 24 months postpartum:

Q5; 36 months postpartum: Q6; Figure 2)48. Together, the questionnaires captured information

on demographics, pregnancy history, breastfeeding, maternal physical and mental health, child

characteristics and development, parenting, child care, family well-being and lifestyle.

Standardized tools were used to assess child development and milestone attainment, and when

available, tools were used across multiple time-points to identify trajectories of development.

Input from health care providers, epidemiologists and community program leaders aided in

optimizing the questionnaires, while pilot testing questionnaires with pregnant women in the

community ensured clarity and cultural sensitivity.

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Figure 2: AOF Participant Recruitment Timeline

Questionnaires were mailed to participants along with a paid return envelope48. When

completed, surveys were returned and participants were given library or store gift cards.

Completed questionnaires were digitized using Teleform (Cardiff Teleform, Version 10.1, 2007)

and underwent a verification process to ensure accuracy.

Among those eligible to participate (n=4003), 85% completed at least one of the

questionnaires during the perinatal period (n=3388), while 74% completed all three

questionnaires48. To be eligible for the current study, participants were required to complete the

questionnaire at 24 months postpartum. In total, 1595 participants were included in this

secondary analysis, a response rate of 75.7% (Figure 3).

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Figure 3: AOF Response Rates163

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3.4 Outcome Measures

To identify children exhibiting delays in either gross or fine motor development at 24

months of age, data collected using the Ages and Stages Questionnaire, third edition (ASQ-3)

were analyzed. The ASQ-3 is a norm-referenced screening tool used to assess communication,

gross motor, fine motor, problem-solving, and personal-social skills164. With 92% intra-parental

score agreement over a 2-week interval and 93% agreement between parental and trained

examiner scores, the ASQ-3 has high test-retest and inter-observer reliability. Moreover, the

ASQ-3 was also selected as it is widely used throughout Alberta165.

For the purpose of this study, a delay in either fine or gross motor development will be

operationalized as scoring one standard deviation below the normative mean for the respective

subscales. A cut-point of one standard deviation below the normative mean was selected as the

developers of the ASQ-3 have categorized scores below this cut-point as in the “monitoring

zone”164. Investigating risk factors for fine and gross motor development scoring in or below the

“monitoring zone” will contribute to improving the identification of children that are susceptible

to developmental delays, but may remain unscreened or unmonitored.

The AOF cohort includes 114 children only exhibiting fine motor delays, 145 children

only exhibiting gross motor delays and 62 children exhibiting both fine and gross motor delays at

24 months. The rationale for the assessment of fine and gross motor development at 24-months is

two-fold. First, the literature suggests that neurodevelopment screening tools are more reliable

and less situationally sensitive for children older than one year of age164. Second, early

intervention for motor development delays are recommended to occur prior to 18 months of

age166,167. By describing factors associated with delayed motor development prior to 24-months

of age, we can identify at-risk children earlier and intervene more effectively.

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3.5 Exposure Variables

The literature suggests motor development is influenced by socio-demographic, maternal

health, birth outcomes, child health and child environmental factors. The proposed variables that

underwent descriptive analysis for consideration in later multivariable logistic regression

analysis are described in Tables 5 & 6.

3.5.1 Sociodemographic Factors

To assess influence of SES on fine and gross motor development, this study investigated

the impact of marital status, maternal education, household income, income support from the

government, maternal employment status, housing type, parental age, ethnicity and the child’s

sex on motor developmental outcomes.

3.5.2 Maternal Health Factors

As the effect of maternal BMI is well reported in the literature92,116,161, this study included

maternal BMI (before and during pregnancy) and gestational weight gain as covariates.

Additional maternal physical health covariates include: frequency of exercise (15-30 minutes per

day) during pregnancy, self-report rating of overall physical health, fetal drug exposure, use of

prescription medication, alcohol, cigarettes or illicit drugs.

In an effort to further explore the effects of maternal mental health on fine and gross

motor outcomes, covariates such as feelings about pregnancy, overall emotional health, maternal

separation anxiety, optimism, parenting morale and social support were also explored. Due to the

conflicting results regarding stress on motor development71,137,139, this study also investigated the

influence of scores from the maternal Perceived Stress Scale on the child’s fine and gross motor

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development. Lastly, measures of maternal anxiety and depression were included to understand

the effect of post-natal maternal mental health on child motor development.

3.5.3 Pregnancy and Birth Outcome Factors

To assess for known risk factors for delayed motor development related to birth

outcomes, this study included term status, type of delivery, pregnancy complications, Apgar

scores, number of babies delivered during pregnancy, and NICU admissions as covariates.

Furthermore, the influence of antenatal steroids on fine and gross motor development will

contribute new information to the literature.

3.5.4 Child Health Factors

This study aims to add to the limited number of studies investigating child health factors

on fine and gross motor development67,76,91,106,108,114,156. To do so, the influence of the child’s

general health and number of visits to health-care professionals were assessed. Moreover, the

influence of children’s communication, gross motor, fine motor, problem solving and personal-

social development at 12 months on fine and motor development at 24 months of age was also

explored.

3.5.5 Environmental Factors

Given the strong evidence supporting an association between parity58,90,92,134,138161 and

motor development this study included the following covariates: number of live births, child

order, number of pregnancies since AOF child born and number of months since last birth and

birth of AOF child. To explore factors related to the family’s health, the partner’s feelings about

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pregnancy, whether the partner smokes, how smoke is handled in the home, a history of abuse

postpartum and whether food is available in the home were also explored.

Lastly, factors related to the child’s immediate environment were also explored. This

included the investigation of the following covariates: how the child was fed in the first week

postpartum, how the child was generally put to sleep, arrangements for the child’s care, the

child’s television, computer or tablet use habits, the child’s frequency of physical activity and

community resource utilization.

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Table 5: Candidate variables

Type Variables Time point

Socio-

Demographics

Marital status Q1, Q4

Maternal Education Q1

Born in Canada Q1

Lived in Canada (# years) Q1

Ethnicity Q1

Maternal Age Q1, EHR

Paternal Age Q1

Household Income Q1, Q4

Income support from the government Q1

Maternal employment status Q2, Q3, Q5

Housing type (i.e. house, apartment, duplex/fourplex, ground dwelling,

etc)

Q1, Q3

Do you have a partner Q3, Q4

Child’s sex Q3, EHR

Maternal

Physical Health

Maternal Body Mass Index (pre-pregnancy) Q1

Maternal Body Mass Index (pregnancy) Q1, Q2

Rating of overall physical health Q1-Q4

How often do you exercise 15-30 mins per day during pregnancy? Q1, Q2

Use of prescription medication during pregnancy Q2

Maternal smoking Q2, Q3, Q4

Maternal alcohol consumption Q2, Q3, Q4

Maternal drug use Q2, Q3, Q4

Maternal

Mental Health

Feelings about pregnancy Q1, Q2

Rate emotional health Q1- Q4

Anxiety:

- Spielberger State & Trait Anxiety Scale (high anxiety score =

>40)

- Maternal Separation Anxiety Scale

Q1 - Q4

Q4

Social Support

- Medical Outcomes Study Social Support (low social support =

scored <70)

- National Longitudinal Survey of Children and Youth Social

Support Scale (low social support = scored <17)

Q1, Q2, Q3

Q4

Perceived Stress Scale (a score of 19+ indicated symptoms of stress

being expressed)

Q1 - Q4

Depression:

- Edinburgh Postnatal Depression Scale (high depression score =

>10)

- Postpartum depression

Q1 - Q4

Q4

Optimism: Life Orientation Test – Revised (low optimism score = <15) Q2

Parenting

- Parenting Morale Index (low parenting morale score = <33)

Q3

Pregnancy &

Birth

Outcomes

Term status (i.e. preterm, late preterm, term) or Gestational age Q3, EHR

Type of delivery (i.e. vaginal, C-section) Q3, EHR

Number of days baby spent in the hospital following pregnancy Q3

Antenatal steroids EHR

Pregnancy complications (i.e. poly/oligo, ROM <37 weeks, bleeding) EHR

Apgar scores EHR

NICU admission EHR

Intrauterine growth restrictions EHR

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a Q1: 22-24 weeks gestation; Q2: 32-36 weeks gestation; Q3: 4 months postpartum; Q4: 12

months postpartum; Q5: 24 months postpartum; EHR: Electronic Health Records

Birth weight/Small-for-gestational age Q3, EHR

Child’s Health Baby’s general health Q4

Healthcare utilization: Number of visits to

- physician/pediatrician

- hospital/urgent care/emergency department

- NICU

- overnight at hospital/hospital re-admit

- specialist/specialty clinic

- chiropractor

- occupational therapist

- physiotherapist

Q3, Q4

Q3, Q4

Q3

Q3, Q4

Q4

Q5

Q5

Q5

Ages and Stages Questionnaire:

- Communication Score

- Problem Solving Score

- Personal-Social Score

- Fine Motor Score

- Gross Motor Score

Q4

Q4

Q4

Q4, Q5

Q4, Q5

Child’s

Environment

Number of live births Q1

Number of months since last birth Q1

Partner happy about pregnancy Q1

Partner smokers Q1

How is smoking handled at home Q1-Q4

Breastfeeding Q3, Q4

How was the baby fed during the first week Q3

Sleep position Q3

Community resource utilization:

- Library

- Parenting classes

- Calgary Learning Center

- Family Literacy programs

- Local immigrant serving group

- Story time in the community

- Informal moms and tots group

- Parenting group on the Internet

- Television show about parenting

- Daycare facility

- Families Matter

- Calgary Child

- A local spiritual institution or organization

- A local fitness center

- Parent Link center

- Local community health center

Q3, Q4, Q5

Abuse postpartum Q3

Occasion where food didn’t last and money was unavailable to buy more Q3

Child care arrangement Q3, Q4, Q5

Child order Q5

Do you have a computer/tablet and your child uses it Q5

Time spent watching TV Q5

Time spent doing physical activity Q5

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Table 6: Categorization of candidate variables

Type Variables Categorization

Outcome Fine Motor Development – ASQ-3 at 24 months

postpartum

0 = On Schedule (>43.43)

1 = Monitor (<43.43)

Gross Motor Development – ASQ-3 at 24 months

postpartum

0 = On Schedule (>46.40)

1 = Monitor (<46.40)

Socio-

Demographics

Marital status 0 = Single/Divorced

1 = Married/Common-law

Maternal Education 0 = High School or less

1 = Some or completed post-

secondary

Born in Canada 0 = Born in Canada

1 = Not born in Canada

Lived in Canada (# years) 0 = >5 years

1 = <5 years

Ethnicity 0 = White

1 = Other

Maternal Age 0 = <35 years of age

1 = >35 years of age

Paternal Age 0 = <35 years of age

1 = >35 years of age

Household Income 0 = <$80,000

1 = >$80,000

Income support from the government 0 = No

1 = Yes

Maternal employment status 0 = Not working

1 = Working

Housing type (i.e. house, apartment, duplex/fourplex,

ground dwelling, etc)

0 = House, townhouse

1 = Apartment, condo,

duplex/fourplex, other

Do you have a partner 0 = Yes

1 = No

Child’s sex 0 = Female

1 = Male

Maternal

Physical

Health

Maternal Body Mass Index (pre-pregnancy) 0 = Underweight/Normal weight

1 = Overweight/Obese

Maternal Body Mass Index (pregnancy) 0 = Underweight/Normal weight

1 = Overweight/Obese

Rating of overall physical health 0 = Excellent, very good, good

1 = Fair, poor

How often do you exercise 15-30 mins per day during

pregnancy?

0 = >3 times

1= <3 times

Use of prescription medication during pregnancy 0 = No

1 = Yes

Maternal smoking 0 = No

1= Yes

Maternal alcohol consumption 0 = No

1 = Yes

Maternal drug use 0 = No

1 = Yes

Maternal Feelings about pregnancy 0 = Happy

1 = Unhappy

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Mental

Health

Rate emotional health 0 = Excellent, very good, good

1 = Fair, poor

Anxiety:

- Spielberger State & Trait Anxiety Scale (high

anxiety score = >40)

- Maternal Separation Anxiety Scale

0 = <40

1 = >40

0 = < 1SD

1 = >1SD

Social Support

- Medical Outcomes Study Social Support (low

social support = scored <70)

- National Longitudinal Survey of Children and

Youth Social Support Scale (low social support =

scored <17)

0 = <70

1 = >70

0 = >17

1 = <17

Perceived Stress Scale (a score of >19 indicated

symptoms of stress being expressed)

0 = <19

1 = >19

Depression:

- Edinburgh Postnatal Depression Scale (high

depression score = >10)

- Postpartum depression

0 = <10

1 = >10

0 = No

1 = Yes

Optimism: Life Orientation Test – Revised (low

optimism score = <15)

0 = >15

1 = <15

Parenting

- Parenting Morale Index (low parenting morale

score = <33)

0 = >33

1 = <33

Pregnancy &

Birth

Outcomes

Term status (i.e. preterm, late preterm, term) or

Gestational age

0 = >37 weeks

1 = < 37 weeks

Type of delivery (i.e. vaginal, c-section) 0 = Vaginal

1 = Caesarean Section

Number of days baby spent in the hospital following

pregnancy

0 = <3 days

1 = >3 days

Antenatal steroids 0 = No

1 = Yes

Pregnancy complications (i.e. poly/oligo, ROM <37

weeks, bleeding)

0 = No

1 = 1 or more

Apgar scores 0 = >7

1 = <7

NICU admission 0 = No

1 = Yes

Intrauterine growth restrictions 0 = No

1 = Yes

Weight-for-length Percentiles at 12 months (WHO

Growth Chart)

0 = >10th percentile, sex-specific

1 = <10th percentile, sex-specific

Birth weight 0 = <2500g

1 = >2500g

Child’s

Health

Baby’s general health 0 = Excellent, very good, good

1 = Fair, poor

Healthcare utilization: Number of visits to

- physician/pediatrician

- hospital/urgent care/emergency department

- NICU

- overnight at hospital/hospital re-admit

0 = None

1 = 1 or more

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- specialist/specialty clinic

- chiropractor

- occupational therapist

- physiotherapist

Ages and Stages Questionnaire:

- Communication Score

- Problem Solving Score

- Personal-Social Score

- Fine Motor Score

- Gross Motor Score

0 = >15.64

1 = <15.64

0 = >27.32

1 = <27.32

0 = >21.73

1 = <21.73

0 = >43.43

1 = <43.43

0 = >46.40

1 = <46.40

Child’s

Environment

Number of live births 0 = None

1 = 1 or more

Number of months since last birth 0 = > 24 months

1 = <24 months

Partner happy about pregnancy 0 = Happy

1 = Unhappy

Partner smokers 0 = No

1 = Yes

How is smoking handled at home 0 = No smoking inside the house

1 = Smoking in the house

Breastfeeding 0 = Yes

1 = No

How was the baby fed during the first week 0 = Only breastfeeding

1 = Most/some breastfeeding

Community resource utilization:

- Library

- Parenting classes

- Calgary Learning Center

- Family Literacy programs

- Local immigrant serving group

- Story time in the community

- Informal moms and tots group

- Parenting group on the Internet

- Television show about parenting

- Daycare facility

- Families Matter

- Calgary Child

- A local spiritual institution or organization

- A local fitness center

- Parenting resource book

- Parent Link center

- Local community health center

0 = >1 or more

1 = None

Abuse postpartum 0 = No

1 = Yes

Occasion where food didn’t last and money was

unavailable to buy more

0 = No

1 = Yes

Child care arrangement 0 = Parent/co-parent/etc.

1 = Day care

Child order 0 = First Child

1 = Other

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Do you have a computer/tablet and your child uses it 0 = No

1 = Yes

Time spent watching TV on a typical day 0 = <1 hour

1 = >1 hour

Time spent doing physical activity 0 = <1 hour

1 = >1 hour

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3.6 Statistical Methods

3.6.1 Descriptive Statistics

To describe the characteristics of the sample used in this analysis, frequencies and

percentages were computed for categorical variables.

3.6.2 Bivariate Analysis

Pearson’s chi-square test was used to assess the relationship between study variables and

fine or gross motor development at 24-months of age. If expected cell counts were less than five,

Fisher’s exact test was employed to calculate the exact p-value for the relationship between two

variables. The use of Fisher’s exact test is appropriate among small sample sizes as it does not

rely on the statistical approximations used in chi-square tests that require large sample sizes.

3.6.3 Multivariable Logistic Regression

Classification trees by recursive partitioning were created to identify candidate risk or

protective factors for both fine and gross motor delays. Using R for Mac OS X168, trees were

created using the default settings of the rpart package169. To attempt to improve the fit of tree, the

number of observations in a node for a split to be attempted was lowered to a minimum of 10.

Using recursive partitioning, important variables could not be identified. As such

candidate variables were identified using bivariate analysis, where statistically significant

(p<0.10) variables were considered eligible for inclusion in the regression models. Of the eligible

variables, priority was given to variables with: 1) evidence supporting an association between the

variable and either fine or gross motor development in the literature, 2) variables with the highest

risk ratios and 3) variables with response rates >80%.

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With 177 and 207 children identified as experiencing fine or gross motor delays,

respectively, there was a sufficient sample size to include 17 variables in a regression model

investigating fine motor delays, and 20 variables in a regression model investigating gross motor

delays170,171. As such, two separate multivariable logistic regression models included up to 17

and 20 of the most relevant variables to examine the effect of the covariates on fine or gross

motor development at 24 months of age, respectively.

In each model, the most relevant variables were simultaneously inserted into the model.

To create a parsimonious model, nonsignificant (p>0.05) variables were omitted one at a time,

where at each iteration the variable with the largest non-significant p-value was removed. If

multiple nonsignificant variables had approximately the same p-value, the variable that was not

measured using a validated scale was removed first. If, however, nonsignificant variables were

identified as confounders, whereby removal of the variable changed any of the estimates by

greater than 10%, the variable remained in the model. All significant or confounding variables

were carried forward and included in the final model. Prior to finalizing the model, any variable

not originally selected for the multivariable model was added one at a time into the model172. If

the variable was neither significant nor a confounder it was removed172,173.

Missing data was addressed using listwise deletion. Through listwise deletion, cases were

dropped from the analysis if data was missing for any of the variables included in the model.

Though listwise deletion decreases the statistical power and does not include all the available

information, it was employed in this analysis as it is assumed that data was missing at random.

As such, if the missingness of the data was random and not related to the outcome, litswise

deletion may produce unbiased estimates.

137

Finally, a Hosmer and Lemeshow test was performed on the final model to assess

goodness-of-fit173. As is standard practice, the Hosmer-Lemeshow test was performed using 10

groups. As part of the Hosmer-Lemeshow test, a chi-square analysis was performed to compare

the observed responses and the expected number of responses according to our model. A large p-

value suggests that there was no significant difference between the observed and expected

responses, suggesting the models was not poorly fitted.

Effect estimates from the final logistic regression model are presented as odd ratios (OR)

with 95% Confidence Intervals (CI). An alpha level of 5% was used for statistical tests.

Statistical analyses were performed using Stata/SE for Mac version 14.1174.

3.7 Ethics

The All Our Families Study was approved by the Child Health Research Office, Alberta

Children’s Hospital, Alberta Health Services, and the Conjoint Health Research Ethics Board of

the Faculties of Medicine, University of Calgary. Written informed consent was obtained from

the study participants at the time of recruitment, who were also provided copies for their records.

138

CHAPTER FOUR: FACTORS RELATED TO DELAYED FINE AND GROSS MOTOR

DEVELOPMENT AMONG ALBERTAN CHILDREN AT 24 MONTHS OF AGE

4.1 Background

Up to 15% of children1,2 between 3-17 years of age experience either poor physical,

intellectual or social development, making developmental delays the most common childhood

disability2. Long-term repercussions of developmental delays, however, can be mitigated among

some children if intervention strategies are initiated early in childhood38. To support early

identification of children experiencing delays, population-wide developmental screening in

Canada has been proposed46. Recently, the Canadian Task Force on Preventive Health Care

assessed the effectiveness of population-based screening in primary care settings for children

aged 1-4 years46. The results of their systematic review informed their recommendation against

broadly screening child development using standardized tools in children aged 1-4 years with no

apparent signs of delay, and whose parents or clinicians have no concerns about development.

This recommendation, however, does not apply to children who present with signs or symptoms

that could indicate developmental problems, or whose development is being closely monitored

because of identified risk factors. Consequently, to ensure children that present with possible

sign of development delays are identified early and appropriately monitored, contemporary at-

risk profiles for developmental delays must be developed175,176.

Among the earliest recognizable risk indicators of global developmental complications is

delayed motor development5. The development of motor skills enables infants to interact with

their environment, shaping later cognitive and linguistic development7,8. The development of

motor skills has been shown to be influenced by sociodemographic, biological, psychosocial and

environmental factors.

139

Children born preterm, with low birth weight or who required neonatal care, have long

been recognized as at risk for motor delays51,52,56,61-63,65,67,70-75,78,82,86,89,92,96,106,107,141. In Canada,

these children are also more likely to receive consistent screening, leading to earlier referrals to

developmental intervention programs175,176. Recently, however, the influence of socioeconomic

factors on motor development has garnered increased attention. Children growing up in families

of low socioeconomic status are at an increased risk of poor fine and gross motor

development81,90,106,107,154,175,176. It has been suggested that children of low-income families may

have less stimulating environments, such as less space inside the home to safely explore,

increasing the risk for developmental delay177,178. Evidence also suggests that environmental

factors increasing a child’s psychosocial stress, such as poor maternal mental

health51,57,58,60,71,137,139 and intimate partner violence68, are also associated with poor motor

development.

Though a variety of biological, sociodemographic and environmental risk factors have

been shown to be independently associated with fine and gross motor development, few studies

have examined the cumulative effects of risk factors110. Moreover, no Canadian studies have

simultaneously assessed the influence of sociodemographic, biological and environmental factors

on motor development. Given the differences in healthcare and community resource

accessibility, sociodemographic profiles, and cultural expectations of motor skills across

nations47, this study aimed to evaluate factors influencing fine and gross motor development of

Albertan children at 24 months of age. Using detailed information collected during perinatal and

early childhood period by the All Our Families (AOF) study, the influence of sociodemographic,

maternal health, birth outcome, child health and child environmental factors on motor

development was assessed48.

140

4.2 Methods

4.2.1 The All Our Families Study

The All Our Families Study (AOF) is a prospective community-based pregnancy cohort,

situated in Calgary, Alberta, Canada (n=3388)48. A detailed overview of the study design,

recruitment, eligibility and data collection is described elsewhere48,179. In brief, women were

recruited through community-based low-risk pregnancy clinics, Calgary Laboratory Services (the

single provider of public health laboratory services), and by word of mouth from May 2008 to

December 2010. To be eligible, women must have been at least 18 years of age, sufficiently

literate in English to complete questionnaires independently and were less than 25-weeks

gestation. Women planning on moving away from Calgary during their pregnancy were

excluded.

The AOF cohort represents the pregnant and parenting population in Calgary48. When

compared with data collected by the Maternity Experiences Survey (MES), a project

implemented by the Public Health Agency of Canada, AOF participants were generally

representative of pregnant women and families in Canada with a few exceptions: the AOF study

reported a greater proportion of women: 1) attending prenatal or childbirth educational classes;

2) over the age of 35; 3) with an annual income greater than $40,000; 4) not experiencing

postpartum depression; and 5) reporting their postpartum health as fair or poor.

Once enrolled into the study, participants were requested to complete three questionnaires

in the perinatal period (22-24 and 32-36 weeks gestation, and 4 months postpartum) and two

questionnaires in the early childhood period (12 and 24 months postpartum)48. Input from health

care providers, epidemiologists and community program leaders aided in optimizing the

questionnaires, while pilot testing questionnaires with pregnant women in the community

141

ensured clarity and cultural sensitivity. Questionnaires collected detailed information on

demographics, lifestyle, mental, psychosocial and physical health, pregnancy history, health

service utilization, quality of life, and breastfeeding. Using unique identifiers, the questionnaire

data was linked to electronic medical records for labour and delivery. These records enabled

validation of maternal report of gestational age, birth weight, child’s sex, multiple gestation

pregnancy, type of delivery, epidural use and labour induction. Electronic health records also

provided additional pertinent details surrounding pregnancy complications and birth outcomes

such as pregnancy complications, antenatal steroid use, Apgar scores, child admission to the

neonatal intensive care unit following birth and intrauterine growth restrictions.

This study is a secondary analysis of data from the AOF study. To be eligible for the

current analysis, participants were required to complete the questionnaire at 24 months

postpartum. Of 2106 participants who were eligible for follow up at 24 months, 1595 completed

the questionnaire for a response rate of 75.7%163.

The All Our Families Study was approved by the Child Health Research Office, Alberta

Children’s Hospital, Alberta Health Services, and the Conjoint Health Research Ethics Board of

the Faculties of Medicine, University of Calgary. Written informed consent was obtained from

the study participants at the time of recruitment, who were also provided copies for their records.

4.2.3 Assessment of Fine and Gross Motor Development

To assess infants’ fine and gross motor development at 24 months of age, mothers were

asked to complete the Ages and Stages Questionnaire-Third Edition (ASQ-3), a validated scale

for measuring child development between 1-66 months of age180. The ASQ-3 is a norm-

referenced screening tool, commonly used in Calgary, Alberta165 to assess five developmental

142

domains: 1) communication, 2) gross motor, 3) fine motor, 4) problem solving, 5) personal-

social164. To complete the questionnaire, parents were asked to indicate if their child could

complete 30 age-appropriate activities. Using parental evaluations of their child’s performance

on each activity, development across each domain was categorized as typical development,

development requiring monitoring (scoring one standard deviation below the normative mean),

or development requiring further professional assessment (scoring two standard deviations below

the normative mean). In this study, fine or gross motor delays were operationalized as scoring

one standard deviation below the normative mean for the respective subscale.

The ASQ-3 has demonstrated high test-retest reliability with 92% agreement between

scores parental scores separated by two-weeks, with intraclass correlation ranging from 0.75-

0.82164. Moreover, the ASQ-3 has also demonstrated high inter-observer reliability with 93%

agreement between parent and trained examiner scores, with intraclass correlations ranging from

0.43-0.69 by area.

4.2.4 Exposure Variables

In the current analysis, sociodemographic, maternal health, birth outcomes, child health

and child environmental factors were considered. Exposure factors were selected based on

theoretical plausibility or empirical evidence from the literature. Assessment point and

categorization of each variable are included in Table 5 and 6.

Sociodemographic factors: During pregnancy, information was collected on marital

status (married/common-law [reference group], single), maternal education (some or completed

post-secondary [reference group], high school or less), maternal employment status (working

[reference group], not working), duration mother has lived in Canada (more than 5 years

143

[reference group], 5 years or less), maternal age (35 years or more [reference group], less than 35

years), paternal age (35 years or more [reference group], less than 35 years), household income

($80,000 or more [reference group], less than $80,000), income support from the government (no

[reference group], yes) and housing type (house/townhouse [reference group],

apartment/condo/duplex/fourplex/other). Postpartum questionnaires updated information on

marital status, household income, employment status and housing type and collected information

on the child’s sex (female [reference group], male).

Maternal health factors: Information was collected on both maternal physical and mental

health. Maternal physical health factors included maternal perception of overall physical health

(excellent/very good/good [reference group], fair/poor), pre-pregnancy body mass index (BMI;

normal weight [reference group], underweight, overweight, obese), BMI during second and third

trimester, weight gain during pregnancy (adequate [reference group], inadequate, excessive),

exercise during pregnancy (three or more times per day [reference group], less than three times

per day), use of prescription medication (no [reference group], yes), and maternal consumption

of tobacco (no [reference group], yes), alcohol or illicit drugs (no [reference group], yes). Mental

health factors included maternal perception of overall emotional health (Excellent/very

good/good [reference group], fair/poor), feelings about pregnancy (happy [reference group],

unhappy), Spielberger State & Trait Anxiety Scale (low symptoms of anxiety [reference group];

high symptoms of anxiety), Medical Outcomes Study Social Support (high social support

[reference group], low social support), National Longitudinal Survey of Children and Youth

Social Support Scale (high social support [reference group], low social support), perceived stress

scale (low perceived stress [reference group], high perceived stress), Edinburgh Postnatal

Depression Scale (low symptoms of depression [reference group], high symptoms of

144

depression), Life Orientation Test – Revised (high optimism [reference group], low optimism),

Parenting Morale Index (high parenting morale [reference group], low parenting morale), history

of mental health conditions (no [reference group], yes) and Maternal Separation Anxiety Scale

(no [reference group], yes).

Pregnancy and birth outcome factors: Together, questionnaires and electronic health

records collected information on numbers of babies delivered during their study pregnancy

(singleton [reference group], higher order pregnancy), the number of days their child spent in the

hospital following delivery (< 3 days [reference group], >3 days), term status of their baby (>37

weeks gestation [reference group], <37 weeks gestation), and their baby’s birth weight (>2500g

[reference group], <2500g). Term status and birth weight were verified using electronic health

records. Electronic health records also provided information on antenatal steroid use (no

[reference group], yes), infection during pregnancy (no [reference group], yes), pregnancy

complications (no [reference group], yes), Apgar scores (no [reference group], yes), neonatal

intensive care unit admission (NICU: no [reference group], yes) and intrauterine growth

restrictions (no [reference group], yes).

Child health factors: Beginning at 4-months postpartum, questionnaires collected

information regarding maternal perception of baby’s general health (excellent/very good/good

[reference group], fair/poor) and number of visits to either a physician/pediatrician (none

[reference group], >1), hospital/urgent care/emergency department (none [reference group], >1),

neonatal intensive care unit (none [reference group], >1), specialist/specialist clinic (none

[reference group], >1), chiropractor (none [reference group], >1), occupational therapist (none

[reference group], >1) or physiotherapist (none [reference group], >1). The number of overnight

stays or re-admissions into a hospital were also recorded (no [reference group], yes). Mothers

145

were also asked to complete the ASQ-3 at 12 months postpartum. Developmental delays were

operationalized as scoring one standard deviation below the normative mean for the respective

subscale.

Child environment factors: Questionnaires collected information on child birth order

(first/only child [reference group], middle or youngest child), number of months since last birth

(>24 months [reference group], <24 months), partners feelings about pregnancy (happy

[reference group], unhappy), partner smoking status (non-smoker [reference group], smoker),

how smoke is handled in the home (No smoking inside the house [reference group], smoking in

the house), breastfeeding practices (yes [reference group], no), how the baby was fed during their

first week of life (only breastfed [reference group], most/some breastfeeding), child’s sleep

position (supine[reference group], prone/on side), community resource utilization (library,

parenting classes, Calgary Learning Center, family literacy programs, local immigrant serving

group, story time in the community, informal moms and tots group, parenting group on the

Internet, television show about parenting, Daycare facility, Families Matter, Calgary’s Child,

local spiritual institution or organization, local fitness center, parenting resource book, parent

Link center, local community health center; no [reference group], yes), maternal abuse

postpartum (no [reference group], yes), food security status (secure [reference group], insecure),

child care arrangement (parent/co-parent/relative [reference group], day care), child

computer/tablet use (<1 hour [reference group], >1 hour), time spent watching television (<1

hour [reference group], >1 hour) and time spend doing physical activity (<1 hour [reference

group], >1 hour).

146

4.2.5 Data Analysis

To describe the characteristics of the sample used in this analysis, frequencies and

percentages were computed. Pearson’s chi-square test was used to assess the relationship

between study variables and fine or gross motor development at 24-months of age. If cell counts

were less than five, Fisher’s exact test was employed.

Two separate multivariable logistic regression models were created to examine the effect

of the covariates on fine or gross motor development at 24 months of age, respectively.

Candidate variables were identified using bivariate analysis, where statistically significant

(p<0.10) variables were considered eligible for inclusion in the regression models. Of the eligible

variables, priority was given to variables with: 1) evidence supporting an association between the

variable and motor development in the literature, 2) variables with the highest risk ratios and 3)

variables with response rates >80%. To create a parsimonious model, nonsignificant (p>0.05)

variables were omitted one at a time, where at each iteration the variable with the largest non-

significant p-value was removed. If, however, nonsignificant variables were identified as

confounders, whereby removal of the variable changed any of the estimates by greater than 10%,

the variable remained in the model. All significant or confounding variables were carried

forward and included in the final model. Prior to finalizing the model, any variable not originally

selected for the multivariable model was added one at a time into the model172. If the variable

was neither significant nor a confounder it is removed. Finally, a Hosmer-Lemeshow test using

10 groups was performed on the final model to assess goodness-of-fit173.

Effect estimates from the final logistic regression model were presented as odd ratios

(OR) with 95% Confidence Intervals (CI). An alpha level of 5% was used for statistical tests.

Bivariate and regression modelling was performed using Stata/SE for Mac version 14.1174.

147

4.3 Results

4.3.1 Participant Characteristics

Table 8 provides a summary of the descriptive statistics for significant variables and fine

or gross motor development at 24-months of age. A complete summary of the descriptive

statistics for each of the study variables is found in Appendix A. Of the participants included in

this analysis 97.9% of mothers were married or in a common-law relationship, 91.7% had some

form of post-secondary education, 91.5% had lived in Canada for more than five years and

72.6% had a household income of $80,000 or more (Table 7). Mothers generally reported high

levels of good overall physical (90.8%) and emotional (92.7%) health. The proportion of women

reporting depression or anxiety during pregnancy was 15.4% and 18.1%, respectively. Similar

proportions of depression (11.1%) and anxiety (13.6%) were also reported at 4 months

postpartum.

Most of the children included in this analysis had a gestational age greater than 37 weeks

(85.5%) with uncomplicated pregnancies (93.6%). Infants were typically delivered vaginally

(75.5%) and most did not require antenatal steroids (96.9%) or neonatal intensive care unit

admission (91.4%). There was approximately an equal proportion of primiparous (48.0%) and

multiparous pregnancies and of male (51.9%) and female (48.1%) children. In total, there were

177 and 207 children identified as experiencing fine or gross motor delays at 24 months of age,

respectively.

148

Table 7: Participant characteristics

Socio-demographic Characteristics n (%) Marital statusa

Single/Divorced/Separated/Widowed

Married/Common-law

28 (2.1)

1,289 (97.9)

Maternal Educationa

High School

Some or completed post-secondary

132 (8.3)

1,452 (91.7)

Time in Canadaa

Born in Canada/Lived in Canada for 5+ years Lived in Canada less than 5 years

1,445 (91.5)

135 (8.5)

Ethnicitya

White/Caucasian Other

1,301 (82.1)

283 (17.9)

Maternal Agea

Less than 35 years of age

35 years of age or older

1,232 (79.3)

321 (20.7)

Household Incomea

<$80,000

>$80,000

418 (27.4)

1,107 (72.6)

Maternal employment statusb

Working

Not working

971 (62.0)

595 (38.0)

Child’s Sexc

Boy Girl

805 (51.9)

745 (48.1)

Maternal Health Characteristics n (%) Rating of overall physical healtha

Good (Excellent, Very Good, Good) Not good (Fair, Poor)

1,438 (90.8)

146 (9.2)

Use of prescription medication during pregnancyb

No Yes

902 (57.6)

665 (42.4)

Maternal smoking during pregnancyb

No

Yes

1,403 (89.4)

166 (10.6)

Maternal alcohol consumption during pregnancyb

No

Yes

811 (51.7)

758 (48.3)

Maternal drug use during pregnancyb

No

Yes

1,507 (96.1)

61 (3.9)

Rate emotional healtha


1,469 (92.7)

115 (7.3)

Maternal anxiety during pregnancyb

No (<40) Yes (>40)

1,256 (81.9)

278 (18.1)

149

Maternal anxiety post-partumc

No (<40)

Yes (>40)

1,278 (86.4)

202 (13.6)

Social support during pregnancyb

Adequate support (70+)

Inadequate support (<70)

1,391 (88.4)

183 (11.6)

Social support post-partumc

Adequate support (70+) Inadequate support (<70)

1,311 (86.1)

211 (13.9)

Perceived Stress post-partumc

Low symptoms of stress Symptoms of stress

1,308 (86.0)

213 (14.0)

Depression during pregnancyb

No (<10)

Yes (>10)

1,339 (84.6)

244 (15.4)

Depression post-partumc

No (<10)

Yes (>10)

1,374 (88.9)

172 (11.1)

Pregnancy and Birth Outcome Characteristics n (%) Term status

>30 weeks’ gestation

< 30 weeks’ gestation

1,533 (99.6)

7 (0.4)

Type of deliveryc

Vaginal

Caesarean section

1,174 (75.7)

377 (24.3)

Antenatal steroidsd

No Yes

1,314 (96.9)

42 (3.1)

Pregnancy complications (i.e. poly/oligo, ROM <37 weeks,

bleeding)d

No

Yes

1,494 (93.6)

103 (6.4)

Apgar scoresd

>7

<7

1,395 (98.6)

20 (1.4)

NICU admissiond

No Yes

1,459 (91.4)

137 (8.6)

Intrauterine growth restrictionsd

No

Yes

1,560 (97.7)

36 (2.3)

Child Health Characteristics n (%) Maternal perception of baby’s general healthe


1,309 (99.4)

8 (0.6)

Child has visited the hospital in first 2 years of life?

No

Yes

773 (57.8)

565 (42.2)

150

Child has visited an occupational therapist in first 2 years of

life?

No

Yes

1,579 (98.9)

17 (1.1)

Child has visited a physiotherapist in first 2 years of life?

No Yes

1,562 (97.9)

34 (2.1)

Ages and Stages Questionnairee

- Communication Score Typical Development

Delayed Development

- Problem Solving Score Typical Development Delayed Development

- Personal-Social Score Typical Development Delayed Development

- Fine Motor Score Typical Development

Delayed Development

- Gross Motor Score Typical Development

Delayed Development

1,042 (94.6)

59 (5.4)

912 (83.1)

186 (16.9)

960 (87.4)

139 (12.6)

999 (90.8)

101 (9.2)

854 (77.6)

246 (22.4)

Child Environment Characteristics n (%) How is smoking handled at homee

No smoking inside the house

Smoking permitted in the house

1,249 (96.7)

43 (3.3)

Was breastfeeding initiated, even for a short period?

No

Yes

33 (2.1)

1,519 (97.9)

Community Resource Utilization

<1 >1

307 (19.2)

1,289 (80.8)

Birth order of the AOB child

Oldest/only child Youngest/Middle

765 (48.0)

830 (52.0)

151

Table 8: Descriptive statistics for the potential sociodemographic, maternal health, birth outcome, child health, and

environmental factors

Gross Motor Delays at 24 months

(Missing n=36) __________________________________________________

Typical

Development

n (row/column%)

Delayed

Development

n (row/column%)

Missing p-value

Fine Motor Delays at 24 months

(Missing n=45) ________________________________________________

Typical

Development

n (row/column%)

Delayed

Development

n (row/column%)

Missing p-value

Sociodemographics Factors

Were you born in Canada?

Yes

No

1092 (87.29/81.25)

252 (84.00/18.75)

159 (12.71/76.81)

48 (16.00/23.19)

11

0.132

1116 (89.93/81.64)

251 (83.39/18.36)

125 (10.07/71.43)

50 (16.61/28.57)

11

0.001

How many years have you lived in

Canada?

>60 months

<60 months

1229 (86.92/91.65)

112 (84.85/8.35)

185 (13.08/90.24)

20 (15.15/9.76)

16

0.086

1253 (89.18/92.00)

109 (82.58/8.00)

152 (10.82/86.86)

23 (17.42/13.14)

16

0.022

How would you describe your ethnic

background?

Other

White/Caucasian

231 (84.62/17.19)

1113 (87.16/82.81)

42 (15.38/20.39)

164 (12.84/79.61)

12

0.261

221 (80.66/16.17)

1146 (90.45/83.83)

53 (19.34/30.46)

121 (9.55/69.54)

12

<0.001

Household income at Q1?

<$80,000

>$80,000

351 (85.40/27.21)

939 (86.78/72.79)

60 (14.60/29.56)

143 (13.22/70.44)

71

0.486

349 (85.54/26.64)

961 (89.31/73.36)

59 (14.46/33.91)

115 (10.69/66.09)

71

0.044

Maternal employment at Q2?

Working

Not Working

836 (87.91/62.90)

493 (84.85/37.10)

115 (12.09/56.65)

88 (15.15/43.35)

30

0.087

845 (89.14/62.41)

509 (88.52/37.59)

103 (10.86/60.95)

66 (11.48/39.05)

30

0.712

Child’s sex (biological) (Q3)

Boy

Girl

690 (87.67/52.55)

623 (85.58/47.45)

97 (12.33/48.02)

105 (14.42/51.98)

46

0.230

684 (87.36/51.20)

652 (90.06/48.80)

99 (12.64/57.89)

72 (9.94/42.11)

46

0.099

152

Maternal Physical Health

Rating of overall physical health at

22-24 weeks gestation?

Excellent/Very Good/Good

Fair/Poor

1224 (86.93/91.14)

119 (83.80/8.86)

184 (13.07/88.89)

23 (16.20/11.11)

12

0.296

1249 (89.09/91.43)

117 (84.17/8.57)

153 (10.91/87.43)

22 (15.83/12.57)

12

0.082

Rating of overall physical health at 4

months postpartum?


Fair/Poor

1161 (86.45/88.36)

153 (87.93/11.64)

182 (13.55/89.66)

21 (12.07/10.34)

45

0.589

1191 (89.15/89.08)

146 (84.39/10.92)

145 (10.85/84.30)

27 (15.61/15.70)

45

0.064

Since becoming pregnant, did you

drink any alcohol?

Yes

No

642 (86.87/48.23)

689 (86.56/51.77)

97 (13.13/47.55)

107 (13.44/52.45)

27

0.855

664 (90.59/48.93)

693 (87.28/51.07)

69 (9.41/40.59)

101 (12.72/59.41)

27

0.040

Since your baby was 4 months old,

have you consumed any alcoholic

drink?

Yes

No

834 (87.51/74.60)

284 (84.78/25.40)

119 (12.49/70.00)

51 (15.22/30.00)

279

0.203

863 (90.84/75.24)

284 (84.78/24.76)

87 (9.16/63.04)

51 (15.22/36.96)

279

0.002

Since your baby was 4 months old,

have you used street drugs?

Yes

No

19 (70.37/1.70)

1099 (87.22/98.30)

8 (29.63/4.73)

161 (12.78/95.27)

280

0.010

22 (81.48/1.92)

1124 (89.49/98.08)

5 (18.52/3.65)

132 (10.51/96.35)

280

0.182

Maternal Mental Health

Rate emotional health at 22-24

weeks gestation

Excellent/Very good/Good

Fair/Poor

1253 (87.20/93.23)

91 (80.53/6.77)

184 (12.80/89.32)

22 (19.47/10.68)

12

0.044

1272 (88.95/93.12)

94 (84.68/6.88)

158 (11.05/90.29)

17 (15.32/9.71)

12

0.172

Rate emotional health at 32-36

weeks gestation


Fair/Poor

1258 (87.12/94.59)

72 (80.00/5.41)

186 (12.88/91.18)

18 (20.00/8.82)

28

0.054

1276 (88.92/94.17)

79 (87.78/5.83)

159 (11.08/93.53)

11 (12.22/6.47)

28

0.738

153

Rate emotional health at 4 months

postpartum


Fair/Poor

1226 (86.77/93.30)

88 (84.62/6.70)

187 (13.23/92.12)

16 (15.38/7.88)

44

0.534

1254 (89.19/93.79)

83 (80.58/6.21)

152 (10.81/88.37)

20 (19.42/11.63)

44

0.008

Anxiety at 32-36 weeks gestation

No (<40)

Yes(>40)

1064 (86.50/81.72)

238 (87.18/18.28)

166 (13.50/82.59)

35 (12.82/17.41)

6

0.767

1098 (89.56/82.74)

229 (85.13/17.26)

128 (10.44/76.19)

40 (14.87/23.81)

62

0.037

Anxiety at 12 months postpartum

No (<40)

Yes(>40)

910 (87.16/83.79)

176 (86.27/16.21)

134 (12.84/82.72)

28 (13.73/17.28)

323

0.729

940 (90.21/84.53)

172 (85.15/15.47)

102 (9.79/77.27)

30 (14.85/22.73)

323

0.032

Social Support at 22-24 weeks

gestation

Adequate (<70)

Inadequate (>70)

1188 (87.29/88.92)

148 (82.22/11.08)

173 (12.71/84.39)

32 (17.78/15.61)

22

0.060

1216 (89.81/89.54)

142 (79.78/10.46)

138 (10.19/79.31)

36 (20.22/20.69)

22

<0.001

Social Support at 32-36 weeks

gestation

Adequate (<70)

Inadequate (>70)

1149 (87.51/86.98)

172 (81.52/13.02)

164 (12.49/80.79)

39 (18.48/19.21)

38

0.017

1172 (89.67/87.07)

174 (83.65/12.93)

135 (10.33/79.88)

34 (16.35/20.12)

38

0.010

Social Support at 4 months

postpartum

Adequate (<70)

Inadequate (>70)

1120 (87.30/87.02)

167 (81.07/12.98)

163 (12.70/80.69)

39 (18.93/19.31)

74

0.015

1148 (89.76/87.50)

164 (81.19/12.50)

131 (10.24/77.51)

38 (18.81/22.49)

74

<0.001

Social Support at 12 months

postpartum

Moderate or high support (>17)

Low support (<17)

909 (87.40/81.52)

206 (84.08/18.48)

131 (12.60/77.06)

39 (15.92/22.94)

283

0.167

937 (90.36/81.98)

206 (84.43/18.02)

100 (9.64/72.46)

38 (15.57/27.54)

283

0.007

Perceived Stress at 32-36 weeks

gestation

Low symptoms of stress (<19)

High symptoms of stress (>19)

1090 (86.99/82.76)

227 (85.34/17.24)

163 (13.01/80.69)

39 (14.66/19.31)

43

0.471

1117 (89.50/83.30)

224 (85.50/16.70)

131 (10.50/77.51)

38 (14.50/22.49)

43

0.061

Perceived Stress at 4 months

postpartum



1115 (87.25/86.57)

173 (82.38/13.43)

163 (12.75/81.50)

37 (17.62/18.50)

75

0.055

1141 (89.49/87.10)

169 (82.44/12.90)

134 (10.51/78.82)

36 (17.56/21.18)

75

0.003

154

Perceived Stress at 12 months

postpartum



876 (87.78/80.37)

214 (82.95/19.63)

122 (12.22/73.49)

44 (17.05/26.51)

312

0.041

898 (90.16/80.47)

218 (85.16/19.53)

98 (9.84/72.06)

38 (14.84/27.94)

312

0.022

Depression at 22-24 weeks gestation

No (<10)

Yes (>10)

1140 (87.16/84.88)

203 (84.23/15.12)

168 (12.84/81.55)

38 (15.77/18.45)

13

0.219

1163 (89.32/85.20)

202 (84.87/14.80)

139 (10.68/79.43)

36 (15.14/20.57)

13

0.047

Depression at 32-36 weeks gestation

No (<10)

Yes (>10)

1140 (87.22/85.78)

189 (83.63/14.22)

167 (12.78/81.86)

37 (16.37/18.14)

29

0.142

1163 (89.46/85.83)

192 (85.71/14.17)

137 (10.54/81.07)

32 (14.29/18.93)

29

0.099

Depression at 4 months postpartum

No (<10)

Yes (>10)

1171 (87.19/89.53)

137 (81.55/10.47)

172 (12.81/84.73)

31 (18.45/15.27)

50

0.043

1198 (89.54/90.01)

133 (80.61/9.99)

140 (10.46/81.40)

32 (19.39/18.60)

50

0.001

Pregnancy and Birth Outcome Factors

Number of days baby spent in

hospital after birth?

<3 days

>3 days

1097 (87.27/88.11)

148 (81.32/11.89)

160 (12.73/82.47)

34 (18.68/17.53)

123

0.028

1110 (88.80/87.61)

157 (86.26/12.39)

140 (11.20/84.85)

25 (13.74/15.15)

123

0.317

Antenatal Steroids?

Yes

No

30 (76.92/2.59)

1127 (87.57/97.41)

9 (23.08/5.33)

160 (12.43/94.67)

240

0.050

31 (79.49/2.66)

1133 (88.58/97.34)

8 (20.51/5.19)

146 (11.42/94.81)

240

0.081

Complications during pregnancy?

No

Yes

1262 (86.26/93.27)

91 (93.81/6.73)

201 (13.74/97.10)

6 (6.19/2.90)

0

0.034

1283 (88.24/93.31)

92 (94.85/6.69)

171 (11.76/97.16)

5 (5.15/2.84)

0

0.047

5-minute Apgar Scores

>7

<7

1193 (87.40/98.92)

13 (65.00/1.08)

172 (12.60/96.09)

7 (35.00/3.91)

181

0.003

1201 (88.57/98.69)

16 (80.00/1.31)

155 (11.43/97.48)

4 (20.00/2.52)

181

0.234

NICU admission?

No

Yes

1245 (87.12/92.02)

108 (82.44/7.98)

184 (12.88/88.89)

23 (17.56/11.11)

0

0.131

1266 (89.15/92.07)

109 (83.21/7.93)

154 (10.85/87.50)

22 (16.79/12.50)

0

0.040

Birth weight

None low birth weight (>2500g)

Low birth weight (<2500g)

1174 (86.96/94.75)

65 (77.38/5.25)

176 (13.04/90.26)

19 (22.62/9.74)

128

0.013

1194 (88.91/94.39)

71 (85.54/5.61)

149 (11.09/92.55)

12 (14.46/7.45)

128

0.347

155

Child Health Factors

Has your baby been diagnosed with

any long-term conditions?

Yes

No

66 (79.52/5.90)

1052( 87.38/94.10)

17 (20.48/10.06)

152 (12.62/89.94)

280

0.040

71 (85.54/6.20)

1074 (89.50/93.80)

12 (14.46/8.70)

126 (10.50/91.30)

280

0.260

Breasftfeeding at 12 months?

No

Yes

976 (87.69/72.14)

377 (84.34/27.86)

137 (12.31.66.18)

70 (15.66/33.82)

0

0.078

974 (88.22/70.84)

401 (89.71/29.16)

130 (11.78/73.86)

46 (10.29/26.14)

0

0.404

Communication Development at 12

months of age

On schedule

Delays

896 (87.76/95.93)

38 (66.67/4.07)

125 (12.24/86.81)

19 (33.33/13.19)

495

<0.001

918 (90.09/95.23)

46 (80.70/4.77)

101 (9.91/90.18)

11 (19.30/9.82)

495

0.024

Problem Solving Development at 12

months of age

On schedule

Delays

789 (88.26/84.75)

142 (78.45/15.25)

105 (11.74/72.92)

39 (21.55/27.08)

498

<0.001

816 (91.48/84.91)

145 (80.11/15.09)

76 (8.52/67.86)

36 (19.89/32.14)

498

<0.001

Personal-social Development at 12

months of age

On schedule

Delays

831 (88.40/89.16)

101 (74.26/10.84)

109 (11.60/75.69)

35 (25.74/24.31)

497

<0.001

855 (91.05/88.88)

107 (79.26/11.12)

84 (8.95/75.00)

28 (20.74/25.00)

497

<0.001

Fine Development at 12 months of

age

On schedule

Delays

854 (87.14/91.53)

79 (81.44/8.47)

126 (12.86/87.50)

18 (18.56/12.50)

496

0.116

887 (90.70/92.11)

76 (78.35/7.89)

91 (9.30/81.25)

21 (21.65/18.75)

496

<0.001

Communication Development at 12

months of age

On schedule

Delays

759 (90.90/81.35)

174 (71.90/18.65)

76 (9.10/52.78)

68 (28.10/47.22)

496

<0.001

753 (90.50/78.19)

210 (86.42/21.81)

79 (9.50/70.54)

33 (13.58/29.46)

496

0.067

Number of months between your

last child and this pregnancy

>24 months

<24 months

262 (85.62/37.86)

430 (88.30/62.14)

44 (14.38/43.56)

57 (11.70/56.44)

788

0.271

253 (83.50/36.72)

436 (90.08/63.28)

50 (16.50/51.02)

48 (9.92/48.98)

788

0.006

Partner smokes?

No

Yes

1149 (86.59/86.00)

187 (88.21/14.00)

178 (13.41/87.68)

25 (11.79/12.32)

24

0.517

1179 (89.25/86.88)

178 (85.17/13.12)

142 (10.75/82.08)

31 (14.83/17.92)

24

0.083

156

Did you breastfeed even for a short

time?

Yes

No

1283 (86.40/97.64)

31 (96.88/2.36)

202 (13.60/99.51)

1 (3.12/0.49)

44

0.085

1307 (88.49/97.76)

30 (93.75/2.24)

170 (11.51/98.84)

2 (6.25/1.16)

44

0.354

Community resource utilization at 4

months postpartum

<1

>1

310 (89.86/23.59)

1004 (85.67/76.41)

35 (10.14/17.24)

168 (14.33/82.76)

44

0.045

298 (86.88/22.29)

1039 (89.11/77.71)

45 (13.12/26.16)

127 (10.89/73.84)

44

0.254

Community resource utilization at

12 months postpartum

<1

>1

68 (89.47/6.20)

1028 (86.82/93.80)

8 (10.53/4.88)

156 (13.18/95.12)

307

0.506

62 (81.58/5.51)

1063 (90.08/94.49)

14 (18.42/10.69)

117 (9.92/89.31)

307

0.019

Community resource utilization at

24 months postpartum

<1

>1

265 (88.63/19.59)

1088 (86.28/80.41)

34 (11.37/16.43)

173 (13.72/83.57)

0

0.282

252 (84.28/18.33)

1123 (89.70/81.67)

47 (15.72/26.70)

129 (10.30/73.30)

0

0.008

Health Care Utilization at 4 months

postpartum

<1

>1

975 (87.76/78.06)

274 (82.28/21.94)

136 (12.24/69.74)

59 (17.72/30.26)

118

0.010

992 (89.77/77.62)

286 (86.40/22.38)

113 (10.23/71.52)

45 (13.60/28.48)

118

0.086

Abuse postpartum

No Abuse

Yes Abuse

1233 (87.01/94.63)

70 (78.65/5.37)

184 (12.99/90.64)

19 (21.35/9.36)

55

0.025

1252 (88.79/94.28)

76 (86.36/5.72)

158 (11.21/92.94)

12 (13.64/7.06)

55

0.486

Occasion when food didn’t last

Never

Often/Sometimes

1254 (86.66/95.43)

60 (86.96/4.57)

193 (13.34/95.54)

9 (13.04/4.46)

45

0.944

1281 (88.96/95.88)

55 (80.88/4.12)

159 (11.04/92.44)

13 (19.12/7.56)

45

0.041

Order of AOF child

Oldest/only child

Youngest/Middle

642 (86.06/47.49)

710 (87.33/52.51)

104 (13.94/50.24)

103 (12.67/49.76)

1

0.460

672 (90.44/48.91)

702 (86.99/51.09)

71 (9.56/40.34)

105 (13.01/59.66)

1

0.032

Does your child use your computer

at 24 months of age

Yes

No

774 (87.95/60.19)

512 (84.63/39.81)

106 (12.05/53.27)

93 (15.37/46.73)

77

0.064

789 (90.07/60.18)

522 (87.00/39.82)

87 (9.93/52.73)

78 (13.00/47.27)

77

0.066

157

4.3.2 Factors Associated with Delayed Gross Motor Development

Variables included in the original multivariable logistic regression model were as

follows: emotional health at 22-24 weeks gestation (p=0.044), emotional health at 32-36 weeks

gestation (p=0.054), social support at 32-36 weeks gestation (p=0.017), pregnancy complications

(p=0.034), number of days baby spent in hospital following birth (p=0.028), maternal postpartum

depression (p=0.043), maternal postpartum abuse (p=0.025), child health care utilization at 4

months of age (p=0.010), social support at 4 months postpartum (p=0.015), community resource

utilization at 4 months postpartum (p=0.045), maternal recreational drug use at 4 months

postpartum (p=0.010), and child gross (p<0.001), personal-social (p<0.001), problem solving

(p<0.001) and communication development (p<0.001) at 12 months of age.

The adjusted odds ratios of variables included in the final multivariable model are

presented in Table 9. The Hosmer-Lemeshow test did not suggest that the model was poorly

fitted (p=0.271). Children of mothers who experienced complications during pregnancy had 0.27

(95% CI: 0.08-0.93, p=0.038) times the odds of exhibiting gross motor delays at 24 months of

age, compared with children of mothers not experiencing complications during pregnancy.

Compared to children of mothers not experiencing abuse postpartum, children of abused mothers

exhibited a 2.32-fold (95% CI: 1.12-4.82, p=0.024) increase in the odds of exhibiting gross

motor delays at 24 months. Maternal use of recreational drugs at 12 months postpartum was also

associated with delayed gross motor development at 24 months of age (aOR: 4.23; 95% CI: 1.46-

12.2, p=0.008).

Developmental delays at 12 months of age were shown to be risk factors for gross motor

development at 24 months of age (Table 9). Children exhibiting gross motor delays at 12 months

of age had 3.46 (95% CI: 2.29-5.22, p<0.001) times the odds of exhibiting gross motor delays at

158

24 months of age. Moreover, children with delays in problem solving or communication

development at 12 months of age had 1.78 (95% CI: 1.11-2.87, p=0.017) or 2.69 (95% CI: 37-

5.29, p=0.004) times the odds of exhibiting gross motor delays at 24 months of age, compared

with children not experiencing delays at 12 months of age, respectively.

Table 9: Final multivariable logistic regression model of factors influencing gross motor

development at 24 months of age

Risk Factor Adjusted Odds Ratio

(95% CI) p-value

Poor maternal perception of overall emotional

health at 22-24 gestation 1.37 (0.61-3.09) 0.446

Poor maternal perception of overall emotional

health at 32-36 gestation 0.69 (0.27-1.75) 0.429

Pregnancy complications 0.27 (0.08-0.93) 0.038

Baby spent more than 3 days in the hospital

following birth 1.18 (0.66-2.10) 0.576

Maternal postpartum depression 1.57 (0.84-2.93) 0.157

Maternal postpartum abuse 2.32 (1.12-4.82) 0.024

Child required two or more health care services

prior to 4 months of age 1.52 (0.97-2.39) 0.069

Low social support at 4 months postpartum 1.36 (0.78-2.37) 0.278

Child exhibited delays in gross motor development

at 12 months of age 3.46 (2.29-5.22) <0.001

Child exhibited delays in problem solving

development at 12 months of age 1.78 (1.11-2.87) 0.017

Child exhibited delays in communication


Maternal use of recreational drugs at 12 months

postpartum 4.23 (1.46-12.2) 0.008

159

4.3.3 Factors Associated with Delayed Fine Motor Development

Variables included in the multivariable logistic regression model were as follows:

maternal ethnicity (p<0.001), social support at 22-24 weeks gestation (p<0.001), social support

at 32-36 weeks gestation (p=0.010), pregnancy complications (p=0.047), if the baby was

admitted to the NICU (p=0.040), maternal perception of emotional health at 4 months

postpartum (p=0.008), maternal postpartum depression (p=0.001), maternal perceived stress at 4

months postpartum (p=0.003), social support at 4 months postpartum (p<0.001), food security at

4 months postpartum (p=0.041), social support at 12 months postpartum (p=0.007), community

resource utilization at 12 months postpartum (p=0.019), maternal alcohol consumption at 12

months postpartum (p=0.002), and child problem solving (p<0.001), personal-social (p<0.001),

communication (p=0.024) and fine motor development (p<0.001) at 12 months of age.

Children admitted to the NICU had 2.04 (95% CI: 1.06-3.92, p=0.032) times the odds of

exhibiting fine motor delays at 24 months of age, compared with children not admitted to the

NICU (Table 10). Furthermore, both problem solving (aOR: 2.32; 95% CI: 1.42-3.79, p=0.001)

and fine motor (aOR: 2.22; 95% CI: 1.22-4.03, p=0.009) developmental delays at 12 months of

age were risk factors for fine motor development at 24 months of age. Maternal alcohol

consumption at 12 months of age was also a risk factor for fine motor development. Children of

mothers consuming alcohol at 12 months postpartum had a 1.65-fold (95% CI:1.05-2.61,

p=0.031) increase in fine motor development delays compared with children of mothers not

consuming alcohol. Results from the Hosmer-Lemeshow test did not suggest that the model was

poorly fitted (p=0.669).

160

Table 10: Final multivariable logistic regression model of factors influencing fine motor

development at 24 months of age

Risk Factor Adjusted Odds Ratio

(95% CI) p-value

Low social support at 22-24 gestation 1.43 (0.69-2.95) 0.332


Baby was admitted to the NICU 2.04 (1.06-3.92) 0.032

Maternal postpartum depression 2.05 (0.96-4.39) 0.065

High symptoms of perceived stress at 4 months

postpartum 1.02 (0.49-2.14) 0.06


Child exhibited delays in problem solving


Child exhibited delays in fine development at 12

months of age 2.22 (1.22-4.03) 0.009

Less than two community services used at 12

months postpartum 0.66 (0.31-1.41) 0.282

Maternal consumption of alcohol at 12 months

postpartum 1.65 (1.05-2.61) 0.031

4.4 Discussion:

Findings from this Canadian prospective cohort study suggest that risk factors for delayed

gross motor development at 24 month of age are as follows: delays in gross motor, problem

solving and communication development at 12 months, maternal postpartum abuse and maternal

illicit drug use at 12 months postpartum. Pregnancy complications were associated with a

reduction in risk for gross motor delays. Child admission to the neonatal intensive care unit

following birth, maternal consumption of alcohol at 12 months postpartum and delayed problem

solving and fine motor development at 12 months of age were associated with suboptimal fine

motor at 24 months of age.

161

Prenatal drug52,53,85,95,105,107,111,122 and alcohol52,53,72,79,95,103,104 exposure is a known risk

factor for delayed motor development. Few studies, however, have investigated the influence of

postnatal drug and alcohol exposure53,80,181. Using a sample of 400 infants, Little et al.

investigated the influence of alcohol, tobacco, caffeine and marijuana exposure via breastmilk181.

In their analysis, Little et al. described a dose-response relationship whereby increased alcohol

exposure via breastmilk was associated with decreased general motor development scores.

Similar cohort studies, however, have not been able to replicate these results80. As such, the

influence of maternal alcohol and illicit drug consumption at 12 month postpartum on motor

development as described in this study may not be directly due to postpartum alcohol

consumption, but rather a less biased estimate of maternal alcohol consumption during

pregnancy. As there is less social stigma of alcohol consumption prior to pregnancy or following

pregnancy, women may have been more likely to accurately report consumption at these two

time-point. In the All Our Families cohort, 46% of women consuming alcohol in the year prior to

pregnancy did not abstain from alcohol following pregnancy recognition194. Moreover, 13% of

all women reported at least one binge drinking episode that occurred prior to pregnancy

recognition, a prevalence lower than reported in other cohort studies. As such, future research

studies, designed to validate maternal reports of alcohol and drug consumption using laboratory

test, should explore the impact of these exposures postnatally on motor development.

The influence of intimate partner violence (IPV) on fine and gross motor development

has only recently been explored in the literature68. In this study, children of mothers having

experienced abuse in the postpartum period had 2.32 (95% CI: 1.12-4.82, p=0.024) times the

odds of exhibiting gross motor development delays. Similar results were described in an

American cross-sectional study of 16, 595 participants less than 72 months of age68. Children of

162

parents reporting both intimate partner violence and parental psychological distress (PPD) had a

three-fold increase in the odds of exhibiting gross motor delays, compared to children of parents

not reporting either IPV or PPD. Children of mothers only experiencing IPV, however, had

nearly a two-fold increase in the odds of exhibiting fine motor delays. As such, in addition to

screening for child abuse during primary care visits, identifying poor family interactions and

referring parents to supportive services, may help with preventing gross motor developmental

delays at 24-months of age.

The persistence of delays in gross motor development from 12-24 months of age

described in this study are consistent with the literature. In their examination of gross motor

development and joint hypermobility among 59 infants living in Israel, Tirosh et al. reported that

the prevalence of gross motor delays at 5 years was significantly higher among those who also

exhibited gross motor delays at 18 months156. Moreover, Burns et al. also described that motor

development at 12 months of age was a good predictor of motor development at 4 years of

age182.

In addition to the persistence of gross motor delays, our study found that delayed

communication development at 12 months of age significantly increased the odds of children

exhibiting gross motor delays at 24 months of age. It has been suggested that nearly 50% of kids

with developmental speech and language disorders also exhibit deficits in motor

development183,184. A proposed mechanism for this co-occurrence of delays has been described

as atypical brain development, where deviations in the basal ganglia may distort the balance

control and manual dexterity necessary for motor skills and, interfere with language production

and speech initiation183. These results, however, were obtained in cohorts of 23-125 children

163

aged 6-10 years183,184 and therefore our analysis provides the earliest evidence of an association

between early language development and later gross motor development.

This study is the first to describe an association between fine motor development at 12

and 24 months of age. The literature suggests that the influence of early fine motor development

on later motor attainment may not be persistent. In their analysis investigating the influence of

early motor development on later motor and cognitive abilities, Piek et al. described that fine or

gross motor development was not predictive of motor abilities at 6-12 years of age6. This

analysis, however, was limited to 33 children and therefore future large, longitudinal cohort

studies investigating the long-term influence of early motor delays are warranted. Moreover, as

motor development at 12 months of age was shown to be a risk factor for delayed motor

development at 24 months of age cohort studies such as ALSPAC or Target Kids should

investigate whether early developmental delays were risk factors for later motor delays among

their sample.

The association between personal-social development at 12 months of age and fine and

gross motor development at 24 months of age is a novel association. It can be speculated,

however, that this association may be due to the interplay between sensorimotor maturation and

the acquisition of cognitive skills7,8. Problem-solving development at 12 months of age is

measured using a variety of purposeful gross and fine motor tasks, such as placing multiple

objects into a box. If a child is experiencing fine or gross developmental delays, however, these

motor delays may limit the child’s ability to perform the purposeful movements involved in the

problem-solving tasks. Though this proposed mechanism is speculative, the importance of this

association is warranted. The literature suggests that co-occurring developmental delays in

children are generally more severe and persistent than independent delays61,62. As such, if a child

164

exhibits signs or symptoms of developmental delays in problem solving, communication, fine

motor or gross motor development at 12 months of age, the child should be referred to

developmental intervention programs for assessment, monitoring or intervention to reduce the

risk of further delay.

There is little theoretical evidence to suggest a protective effect for gross motor

development among children delivered from pregnancies that include complications such as

oligo/polyhydramnios, bleeding or premature rupture of membranes prior to 37 weeks gestation.

Rather, it is possible that the infants delivered from the complicated pregnancies did not have an

increased risk of gross motor delays, but received increased screening because of their

gestational history. As Canadian children delivered prematurely, with low birth weight or poor

measure of health status, receive the most consistent screening, children of complicated

pregnancies that may have exhibited early gross motor delays were identified at a young age and

provided appropriate interventions. As such, the apparent protective effect of pregnancy

complications may have been the result of improved screening measures. Conversely, our study

found that infants admitted to the NICU following birth had increased risk of experiencing fine

motor delays at 24 months of age. These results may suggest that infants admitted to the NICU

have an increased risk of fine motor delays, that may be associated with the reason for admission

and may be difficult to remediate through intervention.

Limitations of this study include the use of self-report questionnaires to collect detailed

information from the perinatal and early childhood period. The use of self-report questionnaires

are prone to biases related to recall and social desirability. To limit the effect of recall bias,

follow-up questionnaires were distributed frequently, with a maximum duration between surveys

of 12 months. Moreover, the potential effect of social desirability biases was reduced, as

165

exposures during pregnancy and early childhood were collected prior to the outcome variables

and were not associated with medical care. Finally, this study used a screening tool to assess

delays in fine and gross motor development rather than clinical assessment. The ASQ-3,

however, has strong psychometric properties and has been validated in a North American

sample. Furthermore, studies investigating the accuracy of parental report of child development

have shown that information provided by parents is highly accurate4.

The findings from this study contribute to the few studies investigating risk factors for

motor development among Canadian children. The prospective study design and large sample

size enabled the influence of a variety of relevant factors on fine and gross motor development to

be simultaneously assessed. The results from this study support the need for frequent, structured

primary care visits during the early childhood period, as recommended by the Canadian

Paediatric Society. Through these visits, parental concerns regarding development can be

explored, while primary care givers can assess developmental progression. Moreover, the

longitudinal nature of these visits would enable a strong physician-patient relationship to be

established, enabling physicians to assess potential sociodemographic, family interaction and

lifestyle factors demonstrated to influence fine and gross motor development. Ultimately, these

well-baby visits will enable children at risk of motor delays to be identified at 12 months of age

thereby allowing appropriate interventions to be initiated to support children in reaching their

developmental potential.

166

CHAPTER FIVE: CONCLUSIONS

5.1 Summary of Findings

Using data from the All Our Families (AOF) study, this study examined

sociodemographic, maternal health, birth outcome, child health and child environmental factors

influencing fine and gross motor development of Albertan children at 24 months of age. Of the

1595 participants included in this secondary analysis, 177 and 207 children were identified as

experiencing fine or gross motor delays, respectively.

Delays in gross motor, problem solving or communication development at 12 months

were associated with suboptimal gross motor development at 24 months of age. Maternal

postpartum abuse or illicit drug use at 12 months postpartum was also associated with gross

motor delays at 24 months of age. Pregnancy complications were associated with a reduction in

risk for gross motor delays at 24 months of age.

Child admission to the NICU following birth or maternal consumption of alcohol at 12

months postpartum were both associated with delays in fine motor development at 24 months of

age. Moreover, delayed problem solving or fine motor development at 12 months of age were

also associated with suboptimal fine motor development at 12 months of age. No factors

exhibiting a protective effect were found for fine motor development.

5.2 Limitations

There were several limitations with this study. First, detailed information on lifestyle,

mental health, family life and child development were collected during the perinatal and early

childhood period using self-report questionnaires. The use of self-report questionnaires to obtain

such information is prone to biases related to recall and social desirability. For example, in this

167

analysis healthcare and community service utilization during pregnancy and in the postpartum

period were assessed. Given the diversity of services available to participants and the

retrospective reporting of service utilization, these data are susceptible to recall bias. The

literature, however, suggests that recall of health care utilization is accurate between 6-12

months189. As such the effects of recall bias in this study were reduced by limiting the duration

between each follow-up questionnaire to a maximum of 12 months.

In addition to recall bias, reporting errors may have also occurred as select variables

included in this analysis did not specify time frames in their questions. For example, mothers

were asked for their height and weight prior to becoming pregnant. As the questionnaire did not

provide a specific time frame in the question, variability may exist in how each mother answered

the question. Moreover, the variability in these responses may have also influenced the

questionnaire’s assessment of gestational weight gain.

Self-report data may also be subject to biases related to social desirability. The effect of

social desirability may be especially prevalent in questions pertaining to mothers’ consumption

of alcohol, tobacco or illicit drugs during pregnancy; whereas the use of teratogenic substances

may be underreported. The potential effect of these biases are limited, however, as exposures

during pregnancy and early childhood were collected prior to outcome variables and were not

associated with medical care; therefore, women may be less influenced by social desirability

bias.

The categorization of mental health scales is another limitation of the current study.

When dichotomizing continuous variables, a substantial amount of information is lost190. For

example, this study used the Spielberger State-Trait Anxiety Inventory to assess anxiety191. The

State-Trait Anxiety inventory is composed of 40-items, each evaluated on a 4-point scale. In this

168

study, anxiety scores were dichotomized at a score of 40, where scores below 40 represented low

symptoms of anxiety and scores greater or equal to 40 represented high symptoms of anxiety.

Based on this dichotomization, scores of 1 and 39 were considered to be equal, whereas scores of

39 and 40 were considered unequal and represented a difference in anxiety. As such, information

related to participants with small difference in scores is lost. Moreover, the dichotomization of

variables also increased the probability of misclassifications, thereby increasing the risk of type

II error190. Despite these limitations, this study used dichotomized measures of depression,

anxiety, and social support as the dichotomization of these variables have increased clinical

relevance compared to the evaluation of continuous scores.

Lastly, the results from this study are limited in terms of generalizability. Participants of

the AOF study are generally representative of pregnant women and families in Canada with a

few exceptions: the AOF study reported a greater proportion of women: 1) attending prenatal or

childbirth educational classes, 2) over the age of 35, 3) with an annual income greater than

$40,000, 4) not experiencing postpartum depression, and 5) reporting their postpartum health as

fair or poor48. As such, the results from this study can be generalized to the urban pregnant and

parenting population in Canada. Given the sociodemographic and environmental differences

between the urban and rural population192, however, these results cannot be generalized to rural

Canadian families. Moreover, health care and community service accessibility must also be

considered when generalizing these results to similar populations outside of Canada.

5.3 Strengths

The use of community-based services such as primary and prenatal care offices and

Calgary Laboratory Service in the recruitment methodology reduced selection bias and supported

169

the enrollment of a sample reflective of the local pregnant and parenting community48. The AOF

study design also provided many strengths for this analysis. First, the large sample size included

in the cohort enabled the influence of many factors on motor development to be evaluated during

multivariable analysis. Second, the recency of the study ensured that factors being evaluated

were relevant to the local parenting community. Third, the intensive data collection strategy

employed by the AOF study enabled detailed information to be collected through the perinatal

and early childhood periods, while maintaining good response rates. Fourth, the prospective

nature of the study ensured temporality with regards to potential factors influencing fine and

gross motor development at 24 months of age.

The AOF study also provided a valid assessment of maternal health, birth and child

development outcomes. The use of scales such as the Spielberger State & Trait Anxiety Scale,

the Perceived Stress Inventory, Edinburgh Postnatal Depression Scale and the Centre for

Epidemiological Studies Depression Scale provided a valid estimation of maternal mental health.

Moreover, the use of electronic health records enabled the accuracy of maternal reports of birth

outcomes to be assessed. Finally, the high psychometric properties of the Ages and Stages

Questionnaires, along with its validity among a North American population reduced the potential

misclassification bias among our outcome variables.

5.4 Implications of Study Results

Identifying children with developmental delays remains the responsibility of health care

providers and caregivers of young children46. As delayed motor development is among the

earliest recognizable indicators of global developmental complications7,8, elucidating risk factors

of motor delays will support the identification of children at-risk of developmental delays. The

170

results from this study contribute to the few Canadian studies assessing the influence of

sociodemographic, biological and environmental factors on motor

development49,68,69,89,94,102,119,127,135,143-145. The identification of relevant risk factors of fine and

gross motor development in this study may assist both health care providers and caregivers of

young children in identifying children at increased risk of developmental delays at 12 months of

age. Moreover, the results of this study also provide support for the Canadian Pediatric Society’s

(CPS) recommendation for well-baby visits193. Well-baby visits establish a systematic, long-term

follow-up strategy for physicians to meet with children and families. Through these visits, the

CPS aims to ensure primary care visits inform parents of health resources available to them and

promote healthy behaviours. As our study suggests that maternal lifestyle factors, such as

postpartum drug and alcohol consumption at 12 months postpartum, are associated with later

motor development repercussion, well-baby visits would provide an optimal platform for

discussing this with parents. Furthermore, the longitudinal nature of well-baby visits would allow

physicians to establish a strong rapport with families63,193. Through this relationship, family

interaction risk factors, such as maternal postpartum abuse, can be assessed to ensure children

are appropriately monitored.

The results obtained in this study also support the continued assessment of motor

development in the AOF cohort. The identification of pregnancy, birth and maternal factors

influencing delayed motor development highlights the importance of investigating factors

throughout the perinatal and early childhood period. Moreover, given the influence of child

development at 12 months on later fine and gross motor development, trajectory analyses are

warranted. The results from this study may also inform future research related to school-

readiness and factors predicting injuries.

171

5.5 Recommendations for Future Research

Given the influence of child development at 12 months on later fine and gross motor

development as described by this study, trajectory analyses of development are warranted. In

their analysis investigating the influence of early motor development on later motor and

cognitive abilities, Piek et al. described that fine or gross motor development at 2 years of age

was not predictive of motor abilities at 6-12 years of age6. This analysis, however, was limited to

33 children and therefore future large, longitudinal cohort studies investigating the long-term

influence of early motor delays along with diverse covariates are needed. As the AOF study is

continuing to follow-up with children at 3, 5 and 8 years of age, this cohort would provide a

unique opportunity to access the long-term influence of early development on later abilities.

Future research should also target the influence of postnatal maternal alcohol, tobacco

and illicit drug use on child motor development. Fetal exposure to alcohol, tobacco and illicit

drugs is a known risk factor for suboptimal motor development90,120-122,127,129,130,133,134,154,

however, few studies have examined the influence of these exposures in the postnatal

period80,181. Our study is the first to describe an association between maternal consumption of

alcohol and recreational drugs at 12 months postpartum on fine and gross motor development,

respectively. However, maternal self-report of substance use could not be validated using

diagnostic tools. As such, future research studies, designed to validate maternal reports of

alcohol and drug consumption using laboratory test, should explore the impact of these postnatal

exposures on motor development.

Finally, few cohort studies have exclusively investigated the motor development of

minority or rural children72,77,95,108,117,138,147,161. The literature, along with the results of bivariate

analysis in the current study, suggests that ethnicity59,69,138, immigrant status, socioeconomic

172

status and community engagement influence motor development. To understand the influence of

cultural expectations of motor skills and the sociodemographic profile of immigrant and rural

families on motor development, future research must increase the inclusion of minorities and

rural children in studies examining motor development.

173

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APPENDIX A: DESCRIPTIVE STATISTICS FOR THE POTENTIAL SOCIODEMOGRAPHIC, MATERNAL HEALTH,

BIRTH OUTCOME, CHILD HEALTH, AND ENVIRONMENTAL FACTORS

Gross Motor Delays at 24 months

***Missing n=36***

____________________________________________________

Typical

Development

n (row/column%)

Delayed

Development

n (row/column%)

Missing p-value

Fine Motor Delays at 24 months

***Missing n=45***

________________________________________________

Typical

Development

n (row/column%)

Delayed

Development

n (row/column%)

Missing p-value

Socio- Demographics Factors

Marital Status at Q1?

Married/Common-law

Other

1286 (86.60/95.68)

58 (87.88/4.32)

199 (13.40/96.14)

8 (12.12/3.86)

11

0.765

1308 (88.56/95.68)

59 (90.77/4.32)

169 (11.44/96.57)

6 (9.23/3.43)

11

0.582

Marital Status at Q4?

Married/Common-law

Other

1096 (86.98/98.03)

22 (78.57/1.97)

164 (13.02/96.47)

6 (21.43/3.53)

279

0.193

1121 (89.25/97.82)

25 (89.29/2.18)

135 (10.75/97.83)

3 (10.71/2.17)

279

0.995

Highest level of education

completed?

High School

Some or completed post-

secondary

106 (82.81/7.89)

1238 (87.06/92.11)

22 (17.19/10.68)

184 (12.94/89.32)

12

0.175

110 (86.61/8.05)

1257 (88.90/91.95)

17 (13.39/9.77)

157 (11.10/90.23)

12

0.436

Were you born in Canada?

Yes

No

1092 (87.29/81.25)

252 (84.00/18.75)

159 (12.71/76.81)

48 (16.00/23.19)

11

0.132

1116 (89.93/81.64)

251 (83.39/18.36)

125 (10.07/71.43)

50 (16.61/28.57)

11

0.001

How many years have you

lived in Canada?

>60 months

<60 months

1229 (86.92/91.65)

112 (84.85/8.35)

185 (13.08/90.24)

20 (15.15/9.76)

16

0.086

1253 (89.18/92.00)

109 (82.58/8.00)

152 (10.82/86.86)

23 (17.42/13.14)

16

0.022

208

How would you describe

your ethnic background?

Other

White/Caucasian

231 (84.62/17.19)

1113 (87.16/82.81)

42 (15.38/20.39)

164 (12.84/79.61)

12

0.261

221 (80.66/16.17)

1146 (90.45/83.83)

53 (19.34/30.46)

121 (9.55/69.54)

12

<0.001

Maternal age at Q1?

<35 years of age

>35 years of age

1038 (86.14/79.00)

276 (87.90/21.00)

167 (13.86/81.46)

38 (12.10/18.54)

43

0.417

1060 (88.55/79.28)

277 (88.50/20.72)

137 (11.45/79.19)

36 (11.50/20.81)

43

0.978

Paternal age at Q1?

<35 years of age

>35 years of age

817 (86.27/63.48)

470 (86.56/36.52)

130 (13.73/64.04)

73 (13.44/35.96)

74

0.878

846 (89.71/64.33)

469 (87.01/35.67)

97 (10.29/58.08)

70 (12.99/41.92)

74

0.114


<$80,000

>$80,000

351 (85.40/27.21)

939 (86.78/72.79)

60 (14.60/29.56)

143 (13.22/70.44)

71

0.486

349 (85.54/26.64)

961 (89.31/73.36)

59 (14.46/33.91)

115 (10.69/66.09)

71

0.044


<$80,000

>$80,000

340 (85.21/30.80)

764 (87.31/69.20)

59 (14.79/34.71)

111 (12.69/65.29)

293

0.306

349 (87.69/30.80)

784 (89.91/69.20)

49 (12.31/35.77)

88 (10.09/64.23)

293

0.237

Do you receive income support

from the government?

Yes

No

68 (88.31/5.07)

1273 (86.60/94.93)

9 (11.69/4.37)

197 (13.40/95.63)

15

0.666

66 (88.00/4.84)

1297 (88.65/95.16)

9 (12.00/5.14)

166 (11.35/94.86)

15

0.862


Working

Not Working

836 (87.91/62.90)

493 (84.85/37.10)

115 (12.09/56.65)

88 (15.15/43.35)

30

0.087

845 (89.14/62.41)

509 (88.52/37.59)

103 (10.86/60.95)

66 (11.48/39.05)

30

0.712


Maternity leave/stay-at-home

mom/other

Working a job outside the

home/Student

1236 (86.31/94.21)

76 (91.57/5.79)

196 (13.69/96.55)

7 (8.43/3.45)

46

0.172

1262 (88.62/94.46)

74 (89.16/5.54)

162 (11.38/94.74)

9 (10.84/5.26)

46

0.882


Work/study

Not working/studying

971 (86.54/72.30)

372 (86.92/27.70)

151 (13.46/72.95)

56 (13.08/27.05)

11

0.847

991 (88.80/72.55)

375 (88.03/27.45)

125 (11.20/71.02)

51 (11.97/28.98)

11

0.670

209

Type of housing at Q1

House/townhouse

Apartment, condo,


1089 (86.50/81.09)

254 (87.29/18.91)

170 (13.50/82.13)

37 (12.71/17.87)

12

0.722

1105 (88.33/80.89)

261 (90.00/19.11)

146 (11.67/83.43)

29 (10.00/16.57)

12

0.419

Type of housing at Q3

House/townhouse

Apartment, condo,


1151 (86.93/87.80)

160 (84.21/12.20)

173 (13.07/85.22)

30 (15.79/14.78)

47

0.303

1166 (88.67/87.41)

168 (87.96/12.59)

149 (11.33/86.63)

23 (12.04/13.37)

47

0.773

Do you have a partner at Q3?

Yes

No

1302 (86.68/99.24)

10 (76.92/0.76)

200 (13.32/98.52)

3 (23.08/1.48)

46

0.304

1324 (88.62/99.18)

11 (84.62/0.82)

170 (11.38/98.84)

2 (15.38/1.16)

46

0.651

Do you have a partner at Q4?

Yes

No

1105 (86.87/98.75)

14 (82.35/1.25)

167 (13.13/98.24)

3 (17.65/1.76)

278

0.584

1133 (89.35/98.78)

14 (82.35/1.22)

135 (10.65/97.83)

3 (17.65/2.17)

278

0.354

Child’s sex (biological) (Q3)

Boy

Girl

690 (87.67/52.55)

623 (85.58/47.45)

97 (12.33/48.02)

105 (14.42/51.98)

46

0.230

684 (87.36/51.20)

652 (90.06/48.80)

99 (12.64/57.89)

72 (9.94/42.11)

46

0.099

Maternal Physical Health

Rating of overall physical

health at Q1?


Fair/Poor

1224 (86.93/91.14)

119 (83.80/8.86)

184 (13.07/88.89)

23 (16.20/11.11)

12

0.296

1249 (89.09/91.43)

117 (84.17/8.57)

153 (10.91/87.43)

22 (15.83/12.57)

12

0.082


health at Q2?


Fair/Poor

1224 (87.12/92.03)

106 (82.17/7.97)

181 (12.88/88.73)

23 (17.83/11.27)

28

0.113

1247 (89.20/92.03)

108 (85.04/7.97)

151 (10.80/88.82)

19 (14.96/11.18)

28

0.154


health at Q3?


Fair/Poor

1161 (86.45/88.36)

153 (87.93/11.64)

182 (13.55/89.66)

21 (12.07/10.34)

45

0.589

1191 (89.15/89.08)

146 (84.39/10.92)

145 (10.85/84.30)

27 (15.61/15.70)

45

0.064

210


health at Q4?


Fair/Poor

1043 (86.70/93.38)

74 (88.10/6.62)

160 (13.30/94.12)

10 (11.90/5.88)

280

0.715

1073 (89.49/93.71)

72 (85.71/6.29)

126 (10.51/91.30)

12 (14.29/8.70)

280

0.280

How often do you exercise

15-30 mins per day during

pregnancy at Q1?

0-2 per week

3+ per week

649 (86.65/48.36)

693 (86.62/51.64)

100 (13.35/48.31)

107 (13.38/51.69)

13

0.989

653 (87.53/47.80)

713 (89.80/52.20)

93 (12.47/53.45)

81 (10.20/46.55)

13

0.161

How often do you exercise

15-30 mins per day during

pregnancy at Q2?

0-2 per week

3+ per week

741 (86.77/55.76)

588 (86.60/44.24)

113 (13.23/55.39)

91 (13.40/44.61)

29

0.922

748 (88.21/55.20)

607 (89.79/44.80)

100 (11.79/59.17)

69 (10.21/40.83)

29

0.327

During this pregnancy, have

you taken any prescription

medicine?

Yes

No

573 (87.75/43.08)

757 (86.02/56.92)

80 (12.25/39.41)

123 (13.98/60.59)

29

0.324

580 (89.51/42.80)

775 (88.47/57.20)

68 (10.49/40.24)

101 (11.53/59.76)

29

0.524

Since becoming pregnant,

have you smoked cigarettes?

Yes

No

142 (87.65/10.67)

1189 (86.60/89.33)

20 (12.35/9.80)

184 (13.40/90.20)

27

0.708

148 (92.50/10.91)

1208 (88.43/89.09)

12 (7.50/7.06)

158 (11.57/92.94)

27

0.122

Since giving birth, have you

smoked cigarettes?

Yes

No

85 (89.47/6.48)

1227 (86.47/93.52)

10 (10.53/4.95)

192 (13.53/95.05)

47

0.404

84 (88.42/6.30)

1250 (8.59/93.70)

11 (11.58/6.40)

161 (11.41/93.60)

47

0.960

Since your baby was 4

months old, have you

smoked cigarettes?

Yes

No

88 (91.67/7.88)

1029 (86.40/92.12)

8 (8.33/4.71)

162 (13.60/95.29)

280

0.142

87 (91.58/7.60)

1058 (89.06/92.40)

8 (8.42/5.80)

130 (10.94/94.20)

280

0.445

211


did you drink any alcohol?

Yes

No

642 (86.87/48.23)

689 (86.56/51.77)

97 (13.13/47.55)

107 (13.44/52.45)

27

0.855

664 (90.59/48.93)

693 (87.28/51.07)

69 (9.41/40.59)

101 (12.72/59.41)

27

0.040

Since the birth of your

baby, did you drink any

alcohol?

Yes

No

887 (87.30/67.61)

425 (85.34/32.39)

129 (12.70/63.86)

73 (14.66/36.14)

47

0.292

902 (89.48/67.62)

432 (86.75/32.38)

106 (10.52/61.63)

66 (13.25/38.37)

47

0.116


months old, have you

consumed any alcoholic

drink?

Yes

No

834 (87.51/74.60)

284 (84.78/25.40)

119 (12.49/70.00)

51 (15.22/30.00)

279

0.203

863 (90.84/75.24)

284 (84.78/24.76)

87 (9.16/63.04)

51 (15.22/36.96)

279

0.002


have you used street drugs?

Yes

No

48 (85.71/3.61)

1282 (86.74/96.39)

8 (14.29/3.92)

196 (13.26/96.08)

28

0.825

48 (87.27/3.54)

1307 (88.91/96.46)

7 (12.73/4.12)

163 (11.09/95.88)

28

0.705

In the past month, have you

used street drugs?

Yes

No

19 (82.61/1.45)

1290 (86.69/98.55)

4 (17.39/1.98)

198 (13.31/98.02)

50

0.568

19 (82.61/1.43)

1313 (88.72/98.57)

4 (17.39/2.34)

167 (11.28/97.66)

50

0.360


months old, have you used

street drugs?

Yes

No

19 (70.37/1.70)

1099 (87.22/98.30)

8 (29.63/4.73)

161 (12.78/95.27)

280

0.010

22 (81.48/1.92)

1124 (89.49/98.08)

5 (18.52/3.65)

132 (10.51/96.35)

280

0.182

Maternal Mental Health

Feelings about pregnancy?

Happy

Unhappy/Not sure

1180 (86.26/87.86)

163 (89.56/12.14)

188 (13.74/90.82)

19 (10.44/9.18)

13

0.218

1212 (88.86/88.66)

155 (87.57/11.34)

152 (11.14/87.36)

22 (12.43/12.64)

13

0.611

212

Are you happy to be

pregnant?

Happy

Unhappy/Not sure

1274 (86.84/95.79)

56 (83.58/4.21)

193 (13.16/94.61)

11 (16.42/5.39)

28

0.442

1296 (88.77/59

59 (90.77/4.35)

164 (11.23/96.47)

6 (9.23/3.53)

28

0.616

Rate emotional health at Q1


Fair/Poor

1253 (87.20/93.23)

91 (80.53/6.77)

184 (12.80/89.32)

22 (19.47/10.68)

12

0.044

1272 (88.95/93.12)

94 (84.68/6.88)

158 (11.05/90.29)

17 (15.32/9.71)

12

0.172



Fair/Poor

1258 (87.12/94.59)

72 (80.00/5.41)

186 (12.88/91.18)

18 (20.00/8.82)

28

0.054

1276 (88.92/94.17)

79 (87.78/5.83)

159 (11.08/93.53)

11 (12.22/6.47)

28

0.738



Fair/Poor

1226 (86.77/93.30)

88 (84.62/6.70)

187 (13.23/92.12)

16 (15.38/7.88)

44

0.534

1254 (89.19/93.79)

83 (80.58/6.21)

152 (10.81/88.37)

20 (19.42/11.63)

44

0.008



Fair/Poor

1035 (86.97/92.58)

83 (84.69/7.42)

155 (13.03/91.18)

15 (15.31/8.82)

279

0.521

1063 (89.55/92.76)

83 (85.57/7.24)

124 (10.45/89.86)

14 (14.43/10.14)

279

0.223

Anxiety at Q1

No (<40)

Yes(>40)

1134 (86.83/86.17)

182 (85.05/13.83)

172 (13.17/84.31)

32 (14.95/15.69)

43

0.478

1160 (89.09/86.44)

182 (86.67/13.56)

142 (10.91/83.53)

28 (13.33/16.47)

43

0.302

Anxiety at Q2

No (<40)

Yes(>40)

1064 (86.50/81.72)

238 (87.18/18.28)

166 (13.50/82.59)

35 (12.82/17.41)

6

0.767

1098 (89.56/82.74)

229 (85.13/17.26)

128 (10.44/76.19)

40 (14.87/23.81)

62

0.037

Anxiety at Q3

No (<40)

Yes(>40)

1081 (86.48/86.20)

173 (87.37/13.80)

169 (13.52/87.11)

25 (12.63/12.89)

116

0.732

1110 (89.09/86.85)

168 (86.60/13.15)

136 (10.91/83.95)

26 (13.40/16.05)

62

0.308

Anxiety at Q4

No (<40)

Yes(>40)

910 (87.16/83.79)

176 (86.27/16.21)

134 (12.84/82.72)

28 (13.73/17.28)

323

0.729

940 (90.21/84.53)

172 (85.15/15.47)

102 (9.79/77.27)

30 (14.85/22.73)

323

0.032

213

Maternal Separation

Anxiety Scale

Low symptoms of separation

anxiety

High symptoms of separation

anxiety

937 (87.33/84.80)

168 (84.85/15.20)

136 (12.67/81.93)

30 (15.15/18.07)

296

0.342

957 (89.52/84.77)

172 (86.87/15.23)

112 (10.48/81.16)

26 (13.13/18.84)

296

0.271

Social Support at Q1 (MOS)

Adequate (<70)

Inadequate (>70)

1188 (87.29/88.92)

148 (82.22/11.08)

173 (12.71/84.39)

32 (17.78/15.61)

22

0.060

1216 (89.81/89.54)

142 (79.78/10.46)

138 (10.19/79.31)

36 (20.22/20.69)

22

<0.001


Adequate (<70)

Inadequate (>70)

1149 (87.51/86.98)

172 (81.52/13.02)

164 (12.49/80.79)

39 (18.48/19.21)

38

0.017

1172 (89.67/87.07)

174 (83.65/12.93)

135 (10.33/79.88)

34 (16.35/20.12)

38

0.010


Adequate (<70)

Inadequate (>70)

1120 (87.30/87.02)

167 (81.07/12.98)

163 (12.70/80.69)

39 (18.93/19.31)

74

0.015

1148 (89.76/87.50)

164 (81.19/12.50)

131 (10.24/77.51)

38 (18.81/22.49)

74

<0.001

Social Support at Q4

(NLSCY)

Moderate or high support

(>17)

Low support (<17)

909 (87.40/81.52)

206 (84.08/18.48)

131 (12.60/77.06)

39 (15.92/22.94)

283

0.167

937 (90.36/81.98)

206 (84.43/18.02)

100 (9.64/72.46)

38 (15.57/27.54)

283

0.007

Perceived Stress at Q1

Low symptoms of stress

(<20)

High symptoms of stress

(>20)

1145 (86.68/85.51)

194 (86.22/14.49)

176 (13.32/85.02)

31 (13.78/14.98)

17

0.853

1170 (89.04/85.90)

192 (86.10/14.10)

144 (10.96/82.29)

31 (13.90/17.71)

17

0.201



(<19)


(>19)

1090 (86.99/82.76)

227 (85.34/17.24)

163 (13.01/80.69)

39 (14.66/19.31)

43

0.471

1117 (89.50/83.30)

224 (85.50/16.70)

131 (10.50/77.51)

38 (14.50/22.49)

43

0.061

214



(<19)


(>19)

1115 (87.25/86.57)

173 (82.38/13.43)

163 (12.75/81.50)

37 (17.62/18.50)

75

0.055

1141 (89.49/87.10)

169 (82.44/12.90)

134 (10.51/78.82)

36 (17.56/21.18)

75

0.003



(<19)


(>19)

876 (87.78/80.37)

214 (82.95/19.63)

122 (12.22/73.49)

44 (17.05/26.51)

312

0.041

898 (90.16/80.47)

218 (85.16/19.53)

98 (9.84/72.06)

38 (14.84/27.94)

312

0.022

Depression at Q1

No (<10)

Yes (>10)

1140 (87.16/84.88)

203 (84.23/15.12)

168 (12.84/81.55)

38 (15.77/18.45)

13

0.219

1163 (89.32/85.20)

202 (84.87/14.80)

139 (10.68/79.43)

36 (15.14/20.57)

13

0.047

Depression at Q2

No (<10)

Yes (>10)

1140 (87.22/85.78)

189 (83.63/14.22)

167 (12.78/81.86)

37 (16.37/18.14)

29

0.142

1163 (89.46/85.83)

192 (85.71/14.17)

137 (10.54/81.07)

32 (14.29/18.93)

29

0.099

Depression at Q3

No (<10)

Yes (>10)

1171 (87.19/89.53)

137 (81.55/10.47)

172 (12.81/84.73)

31 (18.45/15.27)

50

0.043

1198 (89.54/90.01)

133 (80.61/9.99)

140 (10.46/81.40)

32 (19.39/18.60)

50

0.001

Depression at Q4

No (<10)

Yes (>10)

975 (86.67/87.52)

139 (88.54/12.48)

150 (13.33/89.29)

18 (11.46/10.71)

285

0.516

1004 (89.40/88.07)

136 (87.74/11.93)

119 (10.60/86.23)

19 (12.26/13.77)

285

0.532

Did you experience

postpartum depression

since your most recent

pregnancy?

Yes

No

258 (86.00/23.06)

861 (87.06/76.94)

42 (14.00/24.71)

128 (12.94/75.29)

278

0.635

266 (89.26/23.19)

881 (89.26/76.81)

32 (10.74/23.19)

106 (10.74/76.81)

278

0.999

Optimism (Q2)

High optimism (>15)

Low optimism (<15)

1097 (86.86/83.30)

220 (85.60/16.70)

166 (13.14/81.77)

37 (14.40/18.23)

42

0.590

1120 (89.17/83.33)

224 (87.84/16.67)

136 (10.83/81.44)

31 (12.16/18.56)

42

0.537

215

Parenting Morale Index (Q3)

Moderate to high parenting

morale (>33)

Low parenting morale (<33)

1040 (87.25/83.13)

211 (85.08/16.87)

152 (12.75/80.42)

37 (14.92/19.58)

123

0.358

1065 (89.42/83.59)

209 (86.59/16.41)

126 (10.58/79.75)

32 (13.28/20.25)

123

0.223

Pregnancy and Birth Outcome Factors

Term status

<37 weeks gestation

>37 weeks gestation

188 (85.45/14.41)

1117 (86.93/85.59)

32 (14.55/16.00)

168 (13.07/84.00)

56

0.552

188 (86.24/14.17)

1139 (89.05/85.83)

30 (13.76/17.65)

140 (10.95/82.35)

56

0.226

Term status EHR

<30 weeks gestation

>30 weeks gestation

6 (75.00/0.05)

1203 (87.17/99.50)

2 (25.00/1.12)

177 (12.83/98.88)

178

0.306

8 (100.00/0.66)

1212 (88.40/99.34)

0 (0.00/0.00)

159 (11.60/100.00)

178

0.306

Type of delivery

Vaginal

C-Section

992 (86.71/75.55)

321 (86.29/24.45)

152 (13.29/74.88)

51 (13.71/25.12)

45

0.835

1010 (88.67/75.60)

326 (88.35/24.40)

129 (11.33/75.00)

43 (11.65/25.00)

45

0.863

Number of days baby spent

in hospital after birth?

<3 days

>3 days

1097 (87.27/88.11)

148 (81.32/11.89)

160 (12.73/82.47)

34 (18.68/17.53)

123

0.028

1110 (88.80/87.61)

157 (86.26/12.39)

140 (11.20/84.85)

25 (13.74/15.15)

123

0.317

Antenatal Steroids?

Yes

No

30 (76.92/2.59)

1127 (87.57/97.41)

9 (23.08/5.33)

160 (12.43/94.67)

240

0.050

31 (79.49/2.66)

1133 (88.58/97.34)

8 (20.51/5.19)

146 (11.42/94.81)

240

0.081

Complications during

pregnancy?

No

Yes

1262 (86.26/93.27)

91 (93.81/6.73)

201 (13.74/97.10)

6 (6.19/2.90)

0

0.034

1283 (88.24/93.31)

92 (94.85/6.69)

171 (11.76/97.16)

5 (5.15/2.84)

0

0.047

5-minute Apgar Scores

>7

<7

1193 (87.40/98.92)

13 (65.00/1.08)

172 (12.60/96.09)

7 (35.00/3.91)

181

0.003

1201 (88.57/98.69)

16 (80.00/1.31)

155 (11.43/97.48)

4 (20.00/2.52)

181

0.234

216

NICU admission?

No

Yes

1245 (87.12/92.02)

108 (82.44/7.98)

184 (12.88/88.89)

23 (17.56/11.11)

0

0.131

1266 (89.15/92.07)

109 (83.21/7.93)

154 (10.85/87.50)

22 (16.79/12.50)

0

0.040

Intrauterine Growth

Restrictions

No

Yes

1323 (86.75/97.78)

30 (85.71/2.22)

202 (13.25/97.58)

5 (14.29/2.42)

0

0.858

1344 (88.65/97.75)

31 (88.57/2.25)

172 (11.35/97.73)

4 (11.43/2.27)

0

0.988

Birth weight (Q3)

None low birth weight

(>2500g)


1174 (86.96/94.75)

65 (77.38/5.25)

176 (13.04/90.26)

19 (22.62/9.74)

128

0.013

1194 (88.91/94.39)

71 (85.54/5.61)

149 (11.09/92.55)

12 (14.46/7.45)

128

0.347

Birth weight (EHR)

None low birth weight

(>2500g)


1151 (87.46/95.20)

58 (80.56/4.80)

165 (12.54/92.18)

14 (19.44/7.82)

178

0.089

1160 (88.69/95.08)

60 (84.51/4.92)

148 (11.31/93.08)

11 (15.49/6.92)

178

0.283

Small-for-gestational age

Not SGA

SGA

1113 (86.89/90.49)

117 (82.39/9.51)

168 (13.11/87.05)

25 (17.61/12.95)

139

0.138

1129 (88.62/89.96)

126 (89.36/10.04)

145 (11.38/90.62)

15 (10.64/9.38)

139

0.791

Child Health Factors

Baby’s general health


Fair/Poor

1112 (86.81/99.37)

7 (87.50/0.63)

169 (13.19/99.41)

1 (12.50/0.59)

279

0.954

1141 (89.35/99.48)

6 (75.00/0.52)

136 (10.65/98.55)

2 (25.00/1.45)

279

0.191

Has your baby been

diagnosed with any long-

term conditions?

Yes

No

66 (79.52/5.90)

1052( 87.38/94.10)

17 (20.48/10.06)

152 (12.62/89.94)

280

0.040

71 (85.54/6.20)

1074 (89.50/93.80)

12 (14.46/8.70)

126 (10.50/91.30)

280

0.260

217

How was your baby fed in

the last week (~4 months)?

Most, some or no

breastfeeding

Only breastfeeding

485 (87.39/37.83)

797 (85.70/62.17)

70 (12.61/34.48)

133 (14.30/65.52)

77

0.359

483 (87.82/36.90)

826 (89.10/63.10)

67 (12.18/39.88)

101 (10.90/60.12)

77

0.452

Breasftfeeding at 12

months?

No

Yes

976 (87.69/72.14)

377 (84.34/27.86)

137 (12.31.66.18)

70 (15.66/33.82)

0

0.078

974 (88.22/70.84)

401 (89.71/29.16)

130 (11.78/73.86)

46 (10.29/26.14)

0

0.404

Communication

Development

On schedule

Delays

896 (87.76/95.93)

38 (66.67/4.07)

125 (12.24/86.81)

19 (33.33/13.19)

495

<0.001

918 (90.09/95.23)

46 (80.70/4.77)

101 (9.91/90.18)

11 (19.30/9.82)

495

0.024

Problem Solving

Development

On schedule

Delays

789 (88.26/84.75)

142 (78.45/15.25)

105 (11.74/72.92)

39 (21.55/27.08)

498

<0.001

816 (91.48/84.91)

145 (80.11/15.09)

76 (8.52/67.86)

36 (19.89/32.14)

498

<0.001

Personal-social

Development

On schedule

Delays

831 (88.40/89.16)

101 (74.26/10.84)

109 (11.60/75.69)

35 (25.74/24.31)

497

<0.001

855 (91.05/88.88)

107 (79.26/11.12)

84 (8.95/75.00)

28 (20.74/25.00)

497

<0.001

Fine Development

On schedule

Delays

854 (87.14/91.53)

79 (81.44/8.47)

126 (12.86/87.50)

18 (18.56/12.50)

496

0.116

887 (90.70/92.11)

76 (78.35/7.89)

91 (9.30/81.25)

21 (21.65/18.75)

496

<0.001

Communication

Development

On schedule

Delays

759 (90.90/81.35)

174 (71.90/18.65)

76 (9.10/52.78)

68 (28.10/47.22)

496

<0.001

753 (90.50/78.19)

210 (86.42/21.81)

79 (9.50/70.54)

33 (13.58/29.46)

496

0.067

Number of live births

None

1 or more

670 (87.35/78.55)

183 (84.72/21.45)

97 (12.65/74.62)

33 (15.28/25.38)

593

0.313

667 (87.65/77.83)

190 (88.37/22.17)

94 (12.35/78.99)

25 (11.63/21.01)

593

0.774

218

Number of months between

your last child and this

pregnancy

>24 months

<24 months

262 (85.62/37.86)

430 (88.30/62.14)

44 (14.38/43.56)

57 (11.70/56.44)

788

0.271

253 (83.50/36.72)

436 (90.08/63.28)

50 (16.50/51.02)

48 (9.92/48.98)

788

0.006

Is your partner happy

about the pregnancy

Very happy/Happy

No opinion/Unhappy/Very

unhappy

1308 (86.62/97.98)

27 (93.10/2.02)

202 (13.38/99.02)

2 (6.90/0.98)

24

0.308

1331 (88.67/98.16)

25 (86.21/1.84)

170 (11.33/97.70)

4 (13.79/2.30)

24

0.678

Partner smokes?

No

Yes

1149 (86.59/86.00)

187 (88.21/14.00)

178 (13.41/87.68)

25 (11.79/12.32)

24

0.517

1179 (89.25/86.88)

178 (85.17/13.12)

142 (10.75/82.08)

31 (14.83/17.92)

24

0.083

How is smoking handled?


Smoking permitted inside the

house

1306 (86.49/97.75)

30 (93.75/2.25)

204 (13.51/99.03)

2 (6.25/0.97)

20

0.232

1330 (88.55/98.01)

27 (87.10/1.99)

172 (11.45/97.73)

4 (12.90/2.27)

20

0.802




house

1292 (86.60/98.33)

22 (91.67/1.67)

200 (13.40/99.01)

2 (8.33/0.99)

47

0.468

1319 (88.82/98.58)

19 (86.36/1.42)

166 (11.18/98.22)

3 (13.64/1.78)

47

0.717




house

1260 (86.36/98.28)

22 (88.00/1.72)

199 (13.64/98.51)

3 (12.00/1.49)

77

0.813

1286 (88.57/98.47)

20 (80.00/1.53)

166 (11.43/97.08)

5 (20.00/2.92)

77

0.184




house

790 (86.15/71.95)

308 (88.51/28.05)

127 (13.85/76.05)

40 (11.49/23.95)

304

0.269

818 (89.40/72.52)

310 (89.60/27.48)

97 (10.60/72.93)

36 (10.40/27.07)

304

0.919

Did you breastfeed even for

a short time?

Yes

No

1283 (86.40/97.64)

31 (96.88/2.36)

202 (13.60/99.51)

1 (3.12/0.49)

44

0.085

1307 (88.49/97.76)

30 (93.75/2.24)

170 (11.51/98.84)

2 (6.25/1.16)

44

0.354

219

How was the baby fed in the

first week?

Most, some or no

breastfeeding

Only breastfeeding

502 (84.80/39.28)

776 (87.58/60.72)

90 (15.20/45.00)

110 (12.42/55.00)

84

0.125

513 (87.24/39.37)

790 (89.57/60.63)

75 (12.76/44.91)

92 (10.43/55.09)

84

0.169

Community resource

utilization at Q3?

<1

>1

310 (89.86/23.59)

1004 (85.67/76.41)

35 (10.14/17.24)

168 (14.33/82.76)

44

0.045

298 (86.88/22.29)

1039 (89.11/77.71)

45 (13.12/26.16)

127 (10.89/73.84)

44

0.254

Community resource

utilization at Q4?

<1

>1

68 (89.47/6.20)

1028 (86.82/93.80)

8 (10.53/4.88)

156 (13.18/95.12)

307

0.506

62 (81.58/5.51)

1063 (90.08/94.49)

14 (18.42/10.69)

117 (9.92/89.31)

307

0.019

Community resource

utilization at

<1

>1

265 (88.63/19.59)

1088 (86.28/80.41)

34 (11.37/16.43)

173 (13.72/83.57)

0

0.282

252 (84.28/18.33)

1123 (89.70/81.67)

47 (15.72/26.70)

129 (10.30/73.30)

0

0.008

Health Care Utilization at

Q3?

<1

>1

975 (87.76/78.06)

274 (82.28/21.94)

136 (12.24/69.74)

59 (17.72/30.26)

118

0.010

992 (89.77/77.62)

286 (86.40/22.38)

113 (10.23/71.52)

45 (13.60/28.48)

118

0.086

Health Care Utilization at

Q3?

<1

>1

1122 (87.25/82.93)

231 (84.31/17.07)

164 (12.75/79.23)

43 (15.69/20.77)

282

0.193

1133 (88.58/82.40)

242 (88.97/17.60)

146 (11.42/82.95)

30 (11.03/17.05)

282

0.855

Abuse postpartum

No Abuse

Yes Abuse

1233 (87.01/94.63)

70 (78.65/5.37)

184 (12.99/90.64)

19 (21.35/9.36)

55

0.025

1252 (88.79/94.28)

76 (86.36/5.72)

158 (11.21/92.94)

12 (13.64/7.06)

55

0.486

Occasion when food didn’t

last

Never

Often/Sometimes

1254 (86.66/95.43)

60 (86.96/4.57)

193 (13.34/95.54)

9 (13.04/4.46)

45

0.944

1281 (88.96/95.88)

55 (80.88/4.12)

159 (11.04/92.44)

13 (19.12/7.56)

45

0.041

220

Child care arrangement

Partner/Family

members/Friend/Neighbour

Day home/Daycare/Other

741 (86.67/88.11)

100 (88.50/11.89)

114 (13.33/89.76)

13 (11.50/10.24)

604

0.588

754 (88.71/88.71)

96 (86.49/11.29)

96 (11.29/86.49)

15 (13.51/13.51)

604

0.491

Primary type of childcare at

Q4

Mother, relative, nanny

Childcare centre or dayhome

783 (85.57/70.99)

320 (89.39/29.01)

132 (14.43/77.65)

38 (10.61/22.35)

295

0.072

810 (88.91/71.55)

322 (89.94/28.45)

101 (11.09/73.72)

36 (10.06/26.28)

295

0.594

Primary type of childcare at

Q4

Mother, relative, nanny

Childcare centre or dayhome

856 (86.73/63.74)

487 (86.50/36.26)

131 (13.27/63.29)

76 (13.50/36.71)

11

0.900

868 (88.30/63.54)

498 (89.25/36.46)

115 (11.70/65.71)

60 (10.75/34.29)

11

0.574

Order of AOF child

Oldest/only child

Youngest/Middle

642 (86.06/47.49)

710 (87.33/52.51)

104 (13.94/50.24)

103 (12.67/49.76)

1

0.460

672 (90.44/48.91)

702 (86.99/51.09)

71 (9.56/40.34)

105 (13.01/59.66)

1

0.032

Does your child use your

computer?

Yes

No

774 (87.95/60.19)

512 (84.63/39.81)

106 (12.05/53.27)

93 (15.37/46.73)

77

0.064

789 (90.07/60.18)

522 (87.00/39.82)

87 (9.93/52.73)

78 (13.00/47.27)

77

0.066

Time spent watching TV

Less than an hour

An hour or more

737 (86.91/54.47)

616 (86.52/45.53)

111 (13.09/53.62)

96 (13.48/46.38)

0

0.819

756 (89.47/54.98)

619 (87.68/45.02)

89 (10.53/50.57)

87 (12.32/49.43)

0

0.268

Time spent engaging in

physical activity

Less than an hour

An hour or more

17 (77.27/1.26)

1336 (86.87/98.74)

5 (22.73/2.42)

202 (13.13/97.58)

0

0.188

18 (81.82/1.31)

1357 (88.75/98.69)

4 (18.18/2.27)

172 (11.25/97.73)

0

0.309

Documents

Factors Influencing Fine and Gross Motor Development among