For many new parents, one of the most exciting parts of a visit to the pediatrician is learning their baby’s measurements and corresponding percentiles. Is she gaining enough weight? Is she longer than most babies her age? What many parents don’t know is that there have been two different growth charts (one from the Centers for Disease Control and another from the World Health Organization) available to pediatricians, and the assessment of a baby and recommendations for her health could vary dramatically depending on which chart was used in a particular practice.
All of that should change with the recent recommendation from the Centers for Disease Control (CDC) to use the World Health Organization (WHO) growth standards to monitor growth for infants and children ages 0 to 2 in the U.S., in lieu of its own growth charts (although it still recommends their use for monitoring growth in children age 2 and up).
The CDC has made this recommendation for a number of reasons, including:
- The WHO growth standards, released in 2006, establish breastfeeding as the norm. The WHO standards were created using a sample of almost 8,500 babies (from Brazil, Ghana, India, Norway, Oman, and the U.S.) who were predominantly breastfed for at least four months and who were still nursing at a year.
- The CDC growth charts, released in 2000, were being used as standards for how young children should grow, when in fact they merely identified how typical children (both breastfed and formula-fed) did grow during a specific time period (which may not have been in ideal growth patterns). The WHO growth charts are standards, identifying how children should grow, if given optimal conditions.
- The WHO standards are based on a study designed expressly for creating growth charts that measured length and weight at frequent intervals, as opposed to the CDC growth charts that did not include weight data for the first three months of life and used small sample sizes for sex and age groups during the first six months of life.
- The methods used to create the CDC growth charts and the WHO growth charts are similar for children 2-5 years.
What does all of this mean to parents of infants and toddlers? The change may have an impact on how your pediatrician assesses your child. Based on the CDC charts, some parents of breastfed babies have been told to supplement with formula because their child was measuring quite small. Other parents of larger-than-average babies may have been told their baby was right on target, when in fact he was at risk for becoming overweight or obese.
- See the WHO growth chart for boys 0-24 months (length-for-age and weight-for-age percentiles)*
- See the WHO growth chart for girls 0-24 months (length-for-age and weight-for-age percentiles)*
* Although the charts have the CDC logo on the bottom right, the WHO is listed as the data source.
Parents, did you worry about percentiles with your baby?