Is it common for breasts to re-grow after a reduction?

It is possible that with weight gain bread size will increase.  It would be exceedingly rare for breast size to increase in the time frame mentioned and without weight gain. Please see your plastic surgeon or your family physician for an evaluation. 

I am sorry to hear about what you are experiencing however it is rather rare for the breasts to regrow in such a short time with no weight gain.  Perhaps there wasnt much breast tissue removed during surgery so find out exactly how much was removed and go from there.

After breast reduction provided the patient's weight is reasonably stable the results will be effectively permanent. Substantial increase in weight can result in breasts increasing in size.

Thank you for your question and what you are describing without weight gain is unusual unless you are very young and had your reduction done before you had completed full growth.  If otherwise, I would be evaluated by an endocrinologistDr Corbin