A new international growth reference for young children.

Growth references for children are among the most widely used instruments in public health and clinical medicine. A comprehensive review by the World Health Organization (WHO) of the use and interpretation of anthropometric data concluded that the present international growth reference for infants does not describe physiologic growth adequately; thus, a new anthropometric reference was recommended for young children from birth to 5 y. The approach taken by the WHO for development of a new reference is guided by the principle that anthropometric reference data must always reflect the functional context of their intended uses and an awareness of the consequences of their application. The new reference will be constructed from data to be collected in a longitudinal study of infants who will be exclusively or predominantly breast-fed for >/=4 mo with continued breast-feeding throughout the first year, and a cross-sectional study of infants and young children aged 18-71 mo. The sample will be drawn from >/=7 diverse geographic sites around the world. The adopted protocol is expected to provide a single international reference that represents the best standard possible of optimal growth for all children <5 y of age. Furthermore, documentation will be sufficient to allow for possible future revision of the reference as substantial new biological information on the growth of infants and young children becomes available.