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
1
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
2
WHO Charts - development
• 15 year programme of planning, data collection and
analysis
• New study of the growth of breast fed infants of nonsmoking 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
3
Mean length from birth to 24 months for the six MGRS sites
70
60
Growth in length the same in all
centres → one chart valid for all
children worldwide
50
Mean of Length (cm)
80
Brazil
Ghana
India
Norway
Oman
USA
0
200
400
600
Age (days)
4
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.
5
UK-WHO Charts
UK-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.
6
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
7
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
8
Comparison of WHO and UK90 centiles
Comparison
of WHO
and UK90
Downward
shift of centile
lines centiles
15
Boys
Downward shift of centile lines
13
Weight
11
9
By 12 months,
WHO 2nd centile
= UK1990 0.4th
7
5
WHO black
UK 1990 red
3
1
0
13
26
39
52
Age in weeks
9
How will the new charts be different?
• Separate preterm section
• Head circumference extended to 2 years
• Length/height discontinuity at 2 years
10
11
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
12
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
13
Age labelling
• Age errors are the most common source of plotting
mistakes
• Charts marked in both weeks and calendar months
14
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
15
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
16
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
17
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
18