Use WHO data for children younger < 2 yrs and CDC data for > 2 yrs. per Centers for Disease Control (CDC)
Comparison of World Health Organization (WHO) and CDC growth chart weight-for-age measurements for girls aged <24 months
Comparison of World Health Organization (WHO) and CDC growth chart weight-for-age measurements for boys aged <24 months
*Grummer-Strawn, LM, Reinold, C, Krebs, NF, Centers for Disease Control and Prevention (CDC). Use of World Health Organization and CDC growth charts for children aged 0-59 months in the United States. MMWR Recomm Rep 2010; 59:1.
The WHO charts represent a better guide for children <2 yrs. of age => based on a breastfed population; less likely to miscategorize a breastfed baby as being underweight, esp. during the 2nd six months of life.
Kuczmarski, RJ, Ogden, CL, Grummer-Strawn, LM, et al. CDC growth charts: United States. Advance data from vital and health statistics, no. 314, Hyattsville, Maryland: National Center for Health Statistics. 2000.