Prenatal Development And Birth Chapter 3 © 2013 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized

Prenatal Development And Birth

Chapter 3

© 2013 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part.

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Chapter Outline

• Prenatal development• Birth• The postpartum period


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Prenatal Development

• The course of prenatal development• Teratology and hazards to prenatal

development• Prenatal care• Normal prenatal development• http://www.youtube.com/watch?v=fKyljukBE70&noredirect=1


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The Course of Prenatal Development

• Divided into three periods • Germinal, embryonic, and fetal– Germinal period: Takes place in the first two

weeks after conception• Blastocyst: Inner layer of cells • Trophoblast: Outer layer of cells


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– Embryonic period: Occurs two to eight weeks after conception• Embryo - Mass of cells • Three layers of cells – Endoderm, mesoderm, ectoderm• Organogenesis: Organ formation that takes place

during the first two months of prenatal development

– Fetal period: Two months after conception and birth in typical pregnancies


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Figure 3.1 - Significant Developments in the Germinal Period


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Figure 3.2 - The Placenta and the Umbilical Cord


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Figure 3.3 - The Three Trimesters of Prenatal Development


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• Brain– Neurons: Nerve cells, which handle information

processing at the cellular level in the brain• Birth defects related to a failure of the neural tube

– Anencephaly– Spina bifida– Agenesis of the corpus callosum

• Neurogenesis - Generation of new neurons• Neuronal migration - Cells moving outward from their

point of origin to their appropriate locations• http://www.youtube.com/watch?v=mMDPP-Wy3sI


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Teratology and Hazards to Prenatal Development

• Teratogen: Agent that causes a birth defect• Teratology - Field of study that investigates the

causes of birth defects• Teratogen influence– Dose– Genetic susceptibility– Time of exposure


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• Prescription drugs– Streptomycin and tetracycline– Hormones - Progestin and synthetic estrogen– Accutane

• Nonprescription drugs– Diet pills and high dosages of aspirin


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• Psychoactive drugs– Caffeine– Alcohol• Fetal alcohol spectrum disorders: Appear in the off

spring of mothers who drink alcohol heavily during pregnancy• http://www.youtube.com/watch?v=X9ap3Iimimk


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– Nicotine– Cocaine– Methamphetamine– Marijuana– Heroin– Incompatible blood types– Environmental hazards


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– Maternal diseases• Rubella• Syphilis• Genital herpes• AIDS

– Other parental factors• Maternal diet and nutrition• Maternal age• Emotional states and stress• Paternal factors• http://www.ted.com/talks/annie_murphy_paul_what_we_learn_before_we_re_born.html


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Prenatal Care

• Screening for manageable conditions and treatable diseases

• Programs include educational, social, and nutritional services

• Exercise during pregnancy:– Helps prevent constipation– Conditions the body– Reduces excessive weight gain– Is associated with a more positive mental state


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Prenatal Care

• CenteringPregnancy – Relationship-centered program which provides complete prenatal care in a group setting

• Home visitation – Nurse Family Partnership


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Birth

• The birth process• Assessing the newborn• Preterm and low birth weight infants


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Birth Process

• Stages of birth – Three stages– 1st stage - Uterine contractions are 15 to 20

minutes apart and last up to 1 minute– 2nd stage - Begins when the baby’s head starts to

move through the cervix and birth canal • Ends when the baby completely emerges from the

mother’s body

– 3rd stage• Afterbirth: When the placenta, umbilical cord, and

other membranes are detached and expelled


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Birth Process

• In the United States, 99 percent of births take place in hospitals– Midwifery– Doula: Caregiver who provides continuous

physical, emotional, and educational support for the mother before, during, and after childbirth

• Methods of childbirth– Medication• Analgesia, anesthesia, and oxytocin


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Birth Process

– Natural childbirth: Reduces the mother’s pain by decreasing her fear through:• Education about childbirth• Relaxation techniques during delivery

– Prepared childbirth: Special breathing technique to control pushing in the final stages of labor • Detailed anatomy and physiology course


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Birth Process

– Cesarean delivery• Breech position: Baby’s position in the uterus that

causes the buttocks to be the first part to emerge from the vagina• Cesarean delivery: Surgical procedure in which the

baby is removed from the mother’s uterus through:– An incision made in her abdomen


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Assessing the Newborn

• Apgar scale: Assessing the health of newborns at one and five minutes after birth– Evaluates an infant’s heart rate, respiratory effort,

muscle tone, body color, and reflex irritability


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• Brazelton Neonatal Behavioral Assessment Scale (NBAS): Used in the first month of life to assess the newborn’s:– Neurological development, reflexes, and reactions

to people and objects


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• Neonatal Intensive Care Unit Neurobehavioral Scale (NNNS): Assessment of the newborn’s– Behavior, neurological and stress responses, and

regulatory capacities


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Preterm and Low Birth Weight Infants

• Preterm and small for date infants– Low birth weight infants: Weighs less than 5½

pounds at birth– Preterm infants: Born before the completion of 37

weeks of gestation– Small for date infants: Infants’ birth weights are

below normal when the length of pregnancy is considered


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Preterm and Low Birth Weight Infants

• Consequences of preterm birth and low birth weight– Extremely preterm– Very preterm

• Nurturing low birth weight and preterm infants– Kangaroo care: Involves skin-to-skin contact– Massage therapy


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The Postpartum Period

• Physical adjustments• Emotional and psychological adjustments• Bonding


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Postpartum Period

• Period after childbirth that lasts until:– Mother’s body has completed its adjustment and

has returned to a nearly prepregnant state

• Adjustments needed are: – Physical– Emotional– Psychological


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Physical Adjustments


FatigueFatigue

Hormonal ChangesHormonal Changes

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Figure 3.11 - Postpartum Blues and Postpartum Depression among U.S. Women


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Emotional and Psychological Adjustments

• Postpartum depression: Strong feelings of sadness, anxiety, or despair – Have trouble coping with daily tasks in the

postpartum period– Treatment - Antidepressant drugs, psychotherapy,

and regular exercise


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Bonding

• Formation of a physical bond, between parents and their newborn shortly after birth

• Rooming-in arrangement - Baby remains in the mother’s room most of the time during its hospital stay


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Prenatal Development And Birth Chapter 3 © 2013 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized