Question: Why were the growth charts revised?
Answer: 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:
- The sample consisted primarily of white middle-class infants from southwestern Ohio.
- Birth weights were collected from 1929 to 1975 and did not match recent national birth weight distributions.
- Nearly all infants included in the sample were formula-fed.
- Differences between recumbent length measurements from the Fels data and the stature measurements from the NCHS data sets were larger than expected when the transition was made from recumbent length to stature between 24 and 36 months.
