1

An Introduction to the new UK-WHO Growth Charts

Access to training materials of the Royal College of Paediatrics and Child Health [RCCPCH] is gratefully acknowledged

2

Why did the World Health Organisation

think new growth charts were needed?• Differences in weight gain seen between breast fed and

formula fed infants

• Healthy breast fed infants show very similar growth patterns around the world

• Decided to produce charts that set breast feeding as the norm for infant feeding

3

WHO Charts - development• 15 year programme of planning, data collection and

analysis

• New study of the growth of breast fed infants of non-smoking non-deprived mothers in 6 countries (USA, Norway, India, Ghana, Brazil, Oman) birth to 5 years

• Very similar growth patterns in all 6 centres

• Charts are a description of optimal rather than average growth

• Suitable for all children worldwide

4

Age (days)

Me

an

of L

en

gth

(cm

)

0 200 400 600

50

60

70

80

BrazilGhanaIndiaNorwayOmanUSA

Mean length from birth to 24 months for the six MGRS sites

Growth in length the same in all centres → one chart valid for all children worldwide

5

UK-WHO Charts - development

• SACN (Scientific Advisory Committee on Nutrition) recommended:

– Adoption of WHO charts in UK from age 2 weeks to 4 years– Continue to use UK birth and preterm data as no WHO preterm

data

• Royal College of Paediatrics and Child Health [RCPCH] commissioned to design charts and produce educational materials

• An Irish child health review group has adapted the training materials for application in the Irish health care setting- with kind permission from RCPCH.

6

UK-WHO ChartsUK-WHO Growth Chart 0-4 years are used for:• Infants born at term (37 weeks gestation or later)• Healthy infants born preterm from 32 weeks and

before 37 weeks gestation – use the Preterm section on the left of the chart

UK-WHO NICM Growth Chart 23 weeks gestation to 2 years corrected age are used for:

• Infants of less than 32 weeks gestation• Any other infant requiring detailed assessment/

close monitoring After 2 years corrected age UK-WHO 0-4 years charts can be used.

7

UK-WHO Charts - implementation

• Launch date for charts plus supporting materials was set for January 2013

– 0-4yrs A4– PHR charts 0-4yrs A5 format ( 6 charts /3 pages)

– Separate NICM for low birth weight chart 23 weeks gestation to 2 years

• To be used for all new births• No need to re-plot for older children• Charts in current use to continue for those born prior to

January 2013

8

Effect on patterns of growth caused by the change to the WHO standard

Weight

• Charts now allow for neonatal weight loss– Average children no longer drop down chart between

birth and 4 weeks• After first 6 months

– Drop in % below lower centiles and % weight faltering– Rise in % above upper centiles for weight

Height

• Very similar growth in height/length at all ages

9

Comparison of WHO and UK90 centiles

Downward shift of centile lines

Comparison of WHO and UK90 centilesDownward shift of centile lines

Boys

1

3

5

7

9

11

13

15

0 13 26 39 52

Age in weeks

Wei

gh

t

WHO blackUK 1990 red

By 12 months, WHO 2nd centile = UK1990 0.4th

10

How will the new charts be different?

• Separate preterm section

• Head circumference extended to 2 years

• Length/height discontinuity at 2 years

11

12

Why no lines between birth and 2 weeks?

• New charts use UK 1990 data at birth, then WHO data from 2 weeks

• Birth weight charts do not naturally join infancy chart

– Weight at 2 weeks of age not = birth weight at 42 weeks gestation

• Between birth and 2 weeks most infants lose and regain weight and charts cannot allow for this

• Gap emphasises importance of looking at weight gain relative to birth weight in first days, not centile position

13

De-empathised 50th centile

• Avoids confusing messages to parents about perceived ‘need’ for all children to be on 50th centile– Centile labels at both

ends of each curve– 50th centile identifiable

from location of curve label

14

Age labelling

• Age errors are the most common source of plotting mistakes

• Charts marked in both weeks and calendar months

15

Length – height discontinuity

• Centile lines shift down slightly at age 2

• New charts show length up to age 2 years and height from age 2 onwards

• Due to spinal compression, when a child is measured standing they are slightly shorter than when lying down

• Important not to let length to height transition cause worries for parents

• What matters is whether the child continues to follow their new centile position after the transition

16

Personal Child Health [PHR] record charts

• Fewer pages in total

• Fold-out measurement recording page allows plotting while in view

• Information aimed at parents developed via focus groups

17

Chart instructions

• Draws on available research evidence

• Clear guidance on:– method of measuring and plotting– role of length and height measurements– measurement frequency

• Defines range of normality and need for further assessment, but not what action to be taken

• PHR information for parents

18

UK-WHO growth charts summary

• Launched in January 2013 for all new births

• New UK-WHO Charts are a description of optimal rather that average observed growth

• New separate preterm birth weight for use from 32 weeks

• All infants from 37 weeks gestation should be plotted at term (age 0)

• De-emphasised 50th centile, but identifiable from location of curve label

• A4 charts include detailed user instructions

• PHR has information aimed at parents