All pediatricians document their patients' growth in a standard growth chart. It is one of the best ways to evaluate the overall health of a child. It is equally important for parents to know how to interpret the numbers derived from a growth chart. Most pediatricians assume that parents inherently have the knowledge to read a growth chart, but this assumption doesn't always match up to reality.
Pediatricians often refer to the absolute measurements, such as ounces and pounds for your child's weight, and inches or centimeters for height, length, and head circumference. Pediatricians also track the percentile of these measurements. The absolute measurements are straightforward enough, even though they deserve a brief discussion. The percentile of growth requires a more lengthy discussion.
The best way to explain the percentile of growth indicated by the growth chart is to use an example. If your child is in the 25th percentile along the curve for height, it does not mean that his height is only one quarter of an average child's height. Instead, it means that he is taller than 25 percent of his peers who are the same age. He is shorter than the remaining 75 percent of children his age.
There is no reason to be alarmed if your child's growth percentile seems to fluctuate up and down at different ages. Unless there's a steady and persistent slowing or acceleration, this type of fluctuation is expected for normal growth. Children go through growth spurts, and children often go up and down on the percentile curve during the growing years.
If your child plots out very low on the growth curve, it doesn't necessarily mean that there is something wrong with him. Just like adults, healthy children come in all shapes and forms. If your child stays low on the growth curve but nevertheless gains weight steadily at the same rate as other children, most pediatricians will not be alarmed by this growth pattern. On the other hand, if your child starts out around the 95th percentile and suddenly drops down to the 10th percentile in a short period of time, there is usually something wrong. Even if he gains weight and height, the rate of growth may be too slow to be considered normal.
If a sudden slowing in growth occurs, your pediatrician will take a detailed history of your child's total food intake. There are many conditions that can trigger a deceleration of growth, and additional blood tests may be necessary to ascertain the cause.
Pediatricians monitor your baby's head circumference from birth to three years. It is measured with a tape to find out the greatest circumference of the head just above the ears. After three years of age, the growth of the head does not have much clinical significance.
If the size of a child's head increases too slowly, it could indicate a problem with her brain development. In this case, the brain might not be developing as fast as it should. On the other hand, if the head expands too rapidly, it could mean that something is obstructing the flow of fluid inside the brain. This could be an early sign of a brain tumor. Unlike weight and height, more is not necessarily better when it comes to your baby's head circumference.
One of the most common reasons for your baby to have a large head is familial macrocephaly. This means that big heads are inherited, and it doesn't necessarily mean that something is wrong. If a child's parents have large heads, the baby is more than likely going to have a large head circumference as well.
Your pediatrician will alert you if your child's head size is abnormal, and the next step in evaluation depends on other clinical findings.