Updated Japanese growth references for infants and preschool children, based on historical, ethnic and environmental characteristics

AimTo provide updated growth references for Japanese children from birth to 6 years of age, for use in both growth monitoring and child care. MethodsWe analysed data from two national representative surveys that provided cross-sectional data on 3000 areas in the 2005 national census and longitudinal data from 136 hospitals. Growth references for length/height, weight, head circumference and chest circumference were constructed using the lambda-mu-sigma (LMS) method, with estimates of the L, M and S parameters. These updated values were then compared with growth references published by the World Health Organization. ResultsThe 3rd, 50th and 97th smoothed percentile values of length/height, weight, head circumference and chest circumference for boys and girls from birth to 6years are presented. The comparisons show some large differences in median measurements between the charts. ConclusionOur growth references are based on a current, nationally representative sample of Japanese children. The results provide deep insight into child growth from a historical, ethnic and environmental point of view.