What the Docs May Do
Doctors find these calculations helpful when a child is growing more quickly or slowly than expected. It is also helpful when judging the onset of puberty in an older child. As you may know, puberty is occurring at an earlier age these days. The onset of pubic hair or breast budding in girls can occur normally as early as age six! These calculations can help doctors determine whether your child's early development is in the normal range.
Of course, it is easy to spot exceptions to the rule: While Great Uncle John's tall genes may have passed unexpressed through the generations, your child may get lucky and express them, towering over the rest of the family. And if your peanut baby is growing at the bottom of the length curve, rest assured. A baby's early growth pattern, especially with babies born preterm, is a poor predictor of final adult height.
When doctors need a more exact height prediction, they obtain a hand and wrist X-ray (or "bone age") when a child gets a little older. Doctors compare the growth plates in the left hand and wrist to a book of standards. In this way, they can tell whether your child is an early or late bloomer and by how much. This testing is usually ordered by your doctor only if there is a medical indication.
More 6th Month Health Help
Even the most confident parent has concerns about her child's health and wellness from time to time. Learn more about which medical issues are most common at each baby age, here. (If you have any pressing concerns or questions about your baby's health, please check with her healthcare provider.)