title: Comparison of the World Health Organization growth velocity standards with existing US reference data.
abstract: OBJECTIVE
  The goal of this study was to compare World Health Organization (WHO) growth velocity standards with reference data based on US children.
  
  
  METHODS
  Comparisons were made between reference values for weight and length gains based on serial data from US children and the WHO child growth standards. We compared weight velocities for boys and girls for selected percentiles (5th, 25th, 50th, 75th, and 95th) for 1-month intervals from birth to 6 months, 2-month intervals up to 12 months, and 3-month intervals up to 24 months. For length, we compared 2-month intervals from birth to 6 months and 3-month intervals up to 24 months.
  
  
  RESULTS
  WHO and US monthly weight increments were similar at the 5th percentile up to 3 months of age; values for other US percentiles were below the WHO percentiles ∼150 g on average. From 3 months onward, the US values converged to a narrow range of <100 g between estimated percentiles. Two- and 3-month weight gains showed similar variations. Differences between the WHO and US values were more pronounced at the lower end of the distribution. For length, medians were in closer agreement, but as occurred with weight, values at the outer US percentiles converged to a narrower range with increasing age compared with those of the WHO standards.
  
  
  CONCLUSIONS
  There are important differences between the WHO standards and the reference values for growth velocity based on US data. The WHO values are a better tool for assessing growth velocity and making clinical decisions.
authors.affiliation: Department of Nutrition, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland. deonism@who.int
authors.forename: Mercedes
authors.initials: M
authors.lastname: de Onis
authors.forename: Amani
authors.initials: A
authors.lastname: Siyam
authors.forename: Elaine
authors.initials: E
authors.lastname: Borghi
authors.forename: Adelheid W
authors.initials: AW
authors.lastname: Onyango
authors.forename: Ellen
authors.initials: E
authors.lastname: Piwoz
authors.forename: Cutberto
authors.initials: C
authors.lastname: Garza
mesh_terms: D001827:Body Height; D001835:Body Weight; D005260:Female; D057238:Growth Charts; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D014481:United States; D014944:World Health Organization