Parents often wonder how tall their children will be when they grow up. Kids and teens often ask the same question. “Genetics is the probably biggest factor affecting height,” says Dr. David Scher, a pediatric orthopedic surgeon at HSS. “Tall parents usually have tall children, and the opposite is also true.”
All children have “growth plates” - areas of smooth, elastic cartilage found at the end of each long bone in the body. This is where growth takes place. When bones finish growing, the growth plates close. Girls generally stop growing and reach their maximum height between ages 14 and 16, and boys finish their growth between 16 and 18 years of age. Hormonal changes trigger growth and growth spurts, and since hormones work differently in boys and girls, they mature at different times.
Various formulas aim to predict height, but the most accurate way is to monitor a child’s growth over time, according to Dr. Scher. “During an annual visit to the pediatrician, a child’s height and age are recorded,” he says. “The doctor then plots those numbers on a standardized growth chart of national averages for children of the same age and sex. Healthy children tend to follow a curve on the chart, so if you plot growth over time you can see if it’s consistent and get an idea of future height,” he says.
Recordings on a standardized growth chart also indicate how a child’s height compares to his or her peers. Even more important, keeping track of a youngster’s growth can reveal a potential problem. If a child doesn’t appear to be growing at a normal rate, a referral may be made to a pediatric endocrinologist, a doctor who specializes in treating disorders affecting the hormonal system in children.
For pediatric orthopedic surgeons, predicting when a child will finish growing is important when surgery is needed to correct a bone deformity, equalize a difference in leg lengths, or surgically treat scoliosis, according to Dr. Scher. Pediatric orthopedic surgeons can estimate when growth will be completed by determining a child’s “bone age.” They do this by taking an x-ray of the left hand and wrist to see which growth plates are still open. The bone age may be different from the child’s actual age.
Average heights of the entire population have increased over the past century, probably to a large extent due to improvements in nutrition, as well as improved healthcare in general. The best way to ensure that children achieve their optimum growth potential is by making sure they sleep well, have good nutrition and a balanced diet, and see their pediatrician at the recommended intervals for regular well-child check-ups.