Thank you for your query.
I can understand your concern. However you have not shared the pre natal, natal and post natal details for me to fully understand the cause of delayed milestones in your son. Stem cell therapy
or any other therapy will not work. You are rightly following the correct course by providing occupational and speech therapy
to your son. Regular follow up with his pediatrician
and a team of other consultants would be appropriate to bring out the best in your son.
I hope I have answered your query to your satisfaction.
Wishing your son all the best.