Objective: The WHO 2006 Child Growth Standard is based on data from international optimally nourished breastfed infants from birth to age 5 years. We assessed the potential impact of its use on weight and growth monitoring of UK children.
Participants: Full-term members of two population-based UK birth cohorts: the Avon Longitudinal Study of Parents and Children (ALSPAC) Children in Focus sub-cohort (n=1335), and the Gateshead Millenium Baby Study (GMS; n=923).
Design: Growth data from birth to 5 years were converted to Z scores relative to the WHO 2006 Standard.
Results: Compared to the WHO Standard, both UK cohorts had relatively higher birth weights (mean Z scores: GMS 0.17; ALSPAC 0.34) and ALSPAC had higher birth lengths. After birth, length showed a good fit at all ages. By 2-4mo, both cohorts were similar in weight to the WHO median (at 4 months GMS= 0.01; ALSPAC: -0.07), but thereafter the UK cohorts were heavier (mean WHO weight Z score at 12mo: GMS: 0.57; ALSPAC: 0.65). At age 12mo the risk of being classified as underweight (weight <2nd centile) was considerably lower according to the WHO Standard than by the UK 1990 Growth Reference (relative risk: 0.15, 95% CI 0.07-0.32), while the risk of being classified as obese at 4-5 years (BMI >98th centile) was slightly increased (1.35, 95% CI 1.02-1.78).
Conclusions: Adoption of the WHO 2006 Growth Charts would set a markedly lower standard of weight gain beyond age 4mo for UK infants and could support efforts to avoid future childhood obesity. However, the WHO Standard is not representative of size at birth in the UK.
- birth weight
- growth charts
- growth monitoring
- infant growth