Making the switch
Doctors typically use one of two growth charts to measure your baby's progress--the chart created by the Centers for Disease Control and Prevention (CDC) in 2000, or the one by the World Health Organization (WHO). As of Fall 2010, the CDC recommends use of the WHO chart, an international growth standard statistical distribution chart created in 2006 that outlines the rate of growth for children up to 59 months of age living in optimal growth environments in six countries, including the United States. This change is noteworthy because it establishes growth rates based on breastfeeding as the norm, and includes a sample of children outside of the United States. The chart created in 2000 from the CDC is based on children in the United States only.
Why the WHO growth chart?
The CDC has recently recommended the switch to the WHO's chart based on the following:
Once a child reaches the age of two, the CDC recommends using its own chart. This is because between the ages of 2-5, the methods used by the CDC and WHO are similar, and the WHO growth chart only provides information for children up to the age of 5. The CDC growth chart can be used up until the age of 19.
How the change affects your baby
Research conducted in the early 1990s found that breastfed babies grow faster than formula-fed babies in the first few months of life, but then slowed in growth compared to formula-fed babies between the ages of 3-12 months. Therefore, a baby who is exclusively breastfed, but is measured by a chart that is based on breast- and formula-fed babies, would place in a lower percentile of an "average" baby. Oftentimes, doctors would recommend a diet supplemented by formula to help the baby grow.
Because the new WHO charts are based on exclusively or almost exclusively breastfed babies, those who would previously be considered "small" or in a lower percentile are now considered typical, while previously "typical" babies are now in a higher percentile, giving doctors the ability to identify if they are at risk of becoming overweight.
For more information on the use of growth charts and to view the WHO's growth charts for girls and boys, visit the CDC's website.