An Introduction to the new UK-WHO Growth Charts

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

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 Charts UK-WHO Growth Chart 0-4 yearsare usedfor: • 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 ageare 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 15 Boys 13 11 By 12 months, 9 Weight nd WHO 2 centile = UK1990 0.4th 7 5 WHO black UK 1990 red 3 1 0 13 26 39 52 Age in weeks Comparison of WHO and UK90 centiles Downward shift of centile lines

10. How will the new charts be different? • Separate preterm section • Head circumference extended to 2 years • Length/height discontinuity at 2 years

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. 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 De-empathised 50th centile

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