CDC Growth Charts: United States
The growth charts consist of a series of percentile curves that illustrate the distribution of selected body measurements in U.S. children. Pediatric growth charts have been used by pediatricians, nurses, and parents to track the growth of infants, children, and adolescents in the United States since 1977. The 1977 growth charts were developed by the National Center for Health Statistics (NCHS) as a clinical tool for health professionals to determine if the growth of a child is adequate. The 1977 charts were also adopted by the World Health Organization for international use.
When the 1977 NCHS growth charts were first developed, NCHS recommended that they be revised periodically as necessary. With more recent and comprehensive national data now available, along with improved statistical procedures, the 1977 growth charts were revised and updated to make them a more valuable clinical tool for health professionals. The 2000 CDC growth charts represent the revised version of the 1977 NCHS growth charts. Most of the data used to construct these charts come from the National Health and Nutrition Examination Survey (NHANES), which has periodically collected height and weight and other health information on the American population since the early 1960’s.
Growth charts are not intended to be used as a sole diagnostic instrument. Instead, growth charts are tools that contribute to forming an overall clinical impression for the child being measured. The revised growth charts provide an improved tool for evaluating the growth of children in clinical and research settings.
The 2000 CDC Growth Charts and the New BMI-For-Age Charts
The revised growth charts consist of 16 charts (8 for boys and 8 for girls). These charts represent revisions to the 14 previous charts, as well as the introduction of two new body mass index-for-age (BMI-for-age) charts for boys and for girls, ages 2 to 20 years.
Most of the specific differences between the revised charts and the original charts occur in the charts for infants, where national data were previously lacking. The revised head circumference charts also show some noticeable differences when compared to the earlier charts. Compared to the original infant charts that were based on primarily formula-fed infants, the revised growth charts for infants contain a better mix of both breast- and formula-fed infants in the U. S. population. (On average, since 1970 approximately one-half of children born in the United States are reported to have been breast fed at some point, and about one-third have been breast fed for 3 months or more.) The addition of the BMI charts is probably the single most significant new feature of the revised growth charts.
These BMI-for-age charts were created for use in place of the 1977 weight-for-stature charts. BMI (wt/ht2) is calculated from weight and height measurements and is used to judge whether an individual’s weight is appropriate for their height. BMI is the most commonly used approach to determine if adults are overweight or obese and is also the recommended measure to determine if children are overweight. The new BMI growth charts can be used clinically beginning at 2 years of age, when an accurate stature can be obtained.
In recent years, BMI has received increased attention for pediatric use. In 1994, an expert committee charged with developing guidelines for overweight in adolescent preventive services (ages 11-21 years) recommended that BMI be used routinely to screen for overweight adolescents. In addition, in 1997 an expert committee on the assessment and treatment of childhood obesity concluded that BMI should be used to screen for overweight children, ages 2 years and older, using the BMI curves from the revised growth charts. BMI can also be used to characterize underweight (though no expert guidelines exist for the classification of underweight based on BMI).
Methods and Development
For more information about the methods and development of the CDC Growth Charts, please see the 2000 CDC Growth Charts for the United States: Methods and Development Cdc-pdf[PDF – 5M] report.