Your son is short for height (25th percentile) and underweight for age (10th percentile). His BMI is 15.7 (25th percentile). The percentiles compare your son to other children born in the U.S. At the 25th percentile for height, he is taller than 25% and shorter than 75% of children his age. You can check your son’s height and weight percentiles using the Healthy Kid Calculator®.
As a newborn, he was small for length (25th percentile) and average weight (75th percentile) so it appears he got enough nutrition from you during your pregnancy to gain an average amount of weight. It appears that your son’s height is continuing to grow at the 25th percentile since birth, but he is about 5 pounds underweight for height.
Factors which influence height are genetics, nutrition, and environment. Are you or your husband short for height? If yes, then that would explain some of why your son is short for height. Please discuss his height with his doctor. Has his doctor expressed concern about your son’s height or not?
When your son is in a growth spurt he will steadily increase in height and weight. He will grow more rapidly in height and weight during an adolescent growth spurt. He will keep growing until he is 23 but will reach 90% of his adult height by age 18. FYI, girls growth spurt starts with the onset of menses and peaks earlier at age 15.
Don’t worry about your son’s height unless he doesn’t gain height for 6 months. He does need to gain 5 pounds though as he is underweight for height. Next time, do ask his doctor open-ended questions like “what do you think about my son’s height and weight?” If you feel your son would feel self-conscious about this, ask his doctor when your son is out of the room or ask his doctor to call you on the phone to talk privately.