We are getting mixed answers about my son’s development

Last updated on October 16, 2022



I have a few late-bloomer questions.  

My son will turn 16 in April. He has had a steady growth of 2 to 2.5” most of his life but no growth spurt. He is currently at 5’9”.   His pediatrician measured his testicle size at 12 ml this past July (which has grown since the last visit). She felt like he should grow in height at any time and should grow a minimum of 6” since she determined he is in Tanner stage 3.  He has grown a tiny bit since that appointment.  My husband and I were both late bloomers.  He is 6’4” and I am 5’7”.  My son still looks like a boy. 

He has seen an endocrinologist last May.  Their opinions are different.  A wrist x-ray was done and his bone age is 15.  She said he’s been in puberty a long time but is only in the late tanner stage of 2.  She said his predicted height is 5’9” -5’11” (he was 5’8 at the time) before he turns 16 since that is a cutoff for growing.  He has an appointment for another blood test at the end of October to compare testosterone levels.  

It seems like the bone age scan is really driving the endocrinologist’s opinions on my son’s growth.  Is it possible to be in tanner stage 2 with a bone scan of age 15? 

His pediatrician says bone scans can vary and that he is just entering his major growth spurt.  

Any input is appreciated!  Thank you! 


The information you have from the endocrinologist is contradictory. A bone age of 15 would mean that your son is in late stage 4 or early stage 5, which would mean that he would be basically done growing. Saying he is in stage 2 would mean that he has yet to reach his growth spurt. Her predicted height growth would be more in line with a boy at the start of stage 4. Given the mixed signals, I don’t know if you misunderstood her or if there are things involved. By the way, there was a study that showed that those reading the x-rays in a bone age test will skew the results when they know the actual age of the patient.

Testicle sizes of 12 ml would put a boy at late stage 3 or early stage 4. I would expect his growth spurt already to be going. There are boys who never have a major growth spurt. Instead, these boys have a longer time in stage 3.

Given your height and your husband’s height, I would expect your son to reach at least 5’11”. That, at least, matches the two doctors’ estimates.

There isn’t much else I can comment on. “He looks like a boy” is too vague for me to draw conclusions from. That he is still growing is the important point.