3. Why Were the Growth Charts Revised?
One of the most important factors in assessing a child's growth is having an appropriate reference population. When the 1977 NCHS growth charts were developed, limited national survey data were available for young children although data on an infant population were available from the Fels Longitudinal Study. The Fels data were used to construct the infant charts (birth to 36 months). Limitations of the 1977 infant charts were primarily associated with characteristics of the Fels data and included: