My child seems awfully small for her age. Should I be concerned?

We are frequently asked by parents whether their child is an "okay size." In addressing this, we look at several things:

How are the child's height and weight measurements on a standard growth chart?

A child's height and weight can be about average (25th - 75th percentile), above average (greater than the 75th percentile), or below average (less than the 25th percentile.) "Above average" doesn't necessarily mean "too big," and "below average" doesn't necessarily mean "too small." Remember, that these growth charts were compiled using thousands of children from different races and ethnic groups, health histories, and so on.

How big are the child's parents (and brothers and sisters if he or she has any) ?

It is common for a child to be petite, in the 3-10% percentiles for height and weight, if one or both parents are small.

How do the child's height and weight compare to each other?

Generally, we expect a child's height and weight to be proportionate. A child who is somewhere in the middle for height should have a weight that is about average. Short children should weigh less. Disproportionate growth, when a child is very heavy or very slim for his height, can be a cause for concern.

More importantly:

How have the child's height and weight progressed over time? Children who stay at about the same percentile from year to year are much less concerning than children who grow well for several years and then suddenly stop, or significantly slow down, their growth rate.

There's an important, but common, exception: the first two years of life. Size at birth reflects prenatal factors, for example: Was the baby full-term or premature? Did the mother smoke or use drugs? Was the mother's diet during pregnancy adequate? Therefore, infants of even very small mothers can be relatively large, even 8 or 9 pounds, if the mother had a healthy pregnancy. By two years of life, a child's size correlates to the adult height and weight of parents. Therefore, a healthy, medium to large infant with small parent(s) will slow down and gradually seem "smaller" for age by the age of two.

Most importantly:

How is the child's overall health and development? Small children with other medical or developmental issues, such as deafness, seizures, headaches, feeding problems, difficulty walking, or unusual physical features (such as certain kinds of birthmarks) concern pediatricians. Children with these features may have genetic syndromes or other treatable causes of being small, such as hormone problems. Children who are vigorous, happy, developmentally normal, and good eaters, who just happen to be small, are much less concerning.