title: Implications of adopting the WHO 2006 Child Growth Standard in the UK: two prospective cohort studies.
abstract: BACKGROUND
  The WHO 2006 Child Growth Standard is based on data from international optimally nourished breastfed infants from birth to age 5 years.
  
  
  OBJECTIVE
  To assess the potential effect of its use on weight and growth monitoring of UK children.
  
  
  METHODS
  Full-term members of two population-based UK birth cohorts: the Children in Focus sub-cohort of the Avon Longitudinal Study of Parents and Children (ALSPAC) (n = 1335) and the Gateshead Millennium Baby Study (GMS; n = 923).
  
  
  METHODS
  Growth data from birth to 5 years were converted into z-scores relative to the WHO 2006 standard.
  
  
  RESULTS
  Compared with the WHO standard, both UK cohorts had 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 2-4 months, both cohorts were similar in weight to the WHO median (mean WHO weight z-score at 4 months: GMS, 0.01; ALSPAC, -0.07), but thereafter the UK cohorts were heavier (mean WHO weight z-score at 12 months: GMS, 0.57; ALSPAC, 0.65). At age 12 months, 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 (RR = 0.15, 95% CI = 0.07 to 0.32), and the risk of being classified as obese at 4-5 years (body mass index >98th centile) was slightly increased (RR = 1.35, 95% CI = 1.02 to 1.78).
  
  
  CONCLUSIONS
  Adoption of the WHO 2006 Growth Charts would set a markedly lower standard of weight gain beyond the age of 4 months 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.
authors.affiliation: Division of Developmental Medicine, University of Glasgow, Glasgow, UK.
authors.forename: C
authors.initials: C
authors.lastname: Wright
authors.forename: R
authors.initials: R
authors.lastname: Lakshman
authors.forename: P
authors.initials: P
authors.lastname: Emmett
authors.forename: K K
authors.initials: KK
authors.lastname: Ong
mesh_terms: D000375:Aging / Q000502:physiology; D000886:Anthropometry / Q000379:methods; D001724:Birth Weight; D001835:Body Weight; D002675:Child, Preschool; D015331:Cohort Studies; D006128:Growth; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009765:Obesity / Q000175:diagnosis; D011446:Prospective Studies; D012016:Reference Values; D013851:Thinness / Q000175:diagnosis; D006113:United Kingdom; D015430:Weight Gain; D014944:World Health Organization