When interpreting pediatric growth charts, which factors are used to determine a child’s percentile?

• A. Age and Sex
• B. Ethnicity
• C. Height
• D. Weight

Answer: (A)

Percentiles on pediatric growth charts come from comparing a child’s measurement to a reference group defined by age and sex. Growth curves are separated by age and by whether the child is a boy or a girl because growth patterns change as kids get older and differ between sexes. To determine where a child falls, you first identify their age and sex, then plot the relevant measurement (height, weight, or BMI) on the appropriate chart and read the percentile from that age- and sex-specific reference. Ethnicity isn’t the factor used to determine the percentile in standard practice; it’s the age and sex that define the reference group.