“Cryptorchidism” is the medical term used to describe a testicle that has failed to move into its proper position in the scrotum before birth. An “undescended testicle,” the common name for this condition, usually involves only one testicle; both testicles are affected about 10% of the time. Usually, the undescended testicle will move into its proper position on its own within the first few months of life. If not, surgery (orchiopexy) can be undertaken to move the undescended testicle to its proper location in the scrotum. Treatment before one year of age might lower the risk of complications of an undescended testicle, such as infertility and testicular cancer. Preferably surgery should take place before the child is 18 months old.
P.S. An undescended testicle more commonly occurs among babies who are born prematurely.