The Center for Disease Control (CDC) recommends that health care providers in the US use the World Health Organization (WHO) growth standards to monitor growth for infants and children 0 to 2 years of age, and the CDC growth charts to monitor growth for children ages 2 to 20 years.
The CDC provides three primary reasons for using the WHO standards to monitor infant growth. The WHO established standards based on the growth patterns of infants who were primarily breastfed as the norm. In addition, the WHO charts are standards, identifying how children should grow when conditions are optimal; whereas, the CDC charts are references, based on the particular growth pattern of a group of children in the U.S. during a specific time period. Furthermore, the WHO used a longitudinal sample that was equally distributed and had more frequent data points.
For additional information, see: http://www.cdc.gov/growthcharts/who_charts.htm.
The CDC has developed an online training course to assist health care providers in using the WHO growth standards. The course is accessible at: http://www.cdc.gov/nccdphp/dnpao/growthcharts/who/index.htm.