Recommendations and Rationale for Using the WHO Growth Standards in the United States

Development of the U.S. Recommendations to Use the WHO Growth Standards with Children Younger Than 2 Years of Age

Following the release of the WHO Standards in 2006, the Centers for Disease Control and Prevention, (CDC), the National Institutes of Health (NIH), and the American Academy of Pediatrics (AAP) convened a meeting of experts to consider the potential use of the WHO growth standards in clinical settings to monitor growth among children in the United States. Experts considered the rationale for developing an international standard, the methods, statistical comparisons, differences in growth between breast and formula fed infants and practical implications.

Based on the comparison between the CDC growth reference and the WHO growth standards and input from the expert panel, CDC and AAP developed the following recommendations:

• The WHO growth standard charts should be used for children younger than 2 years of age.
• The CDC 2000 growth reference charts should be used for children aged 2 to 19 years.

The CDC growth reference charts are more suited for children 2 years and older because these charts can be used continuously up to age 20 years.

The WHO released the international growth standards for young children ages birth to 5 years of age. However, for children ages 2 to 5 years, the WHO BMI-for-age charts offer little advantage over the CDC BMI-for-age charts for the assessment of child growth from 2 to 5 years of age as the data collection methodology was similar for the two charts. For example, the data used to construct the curves are cross-sectional and sample selection was similar.