The testicles develop in the abdomen and usually descend into the scrotal sacs by the time of birth. When one or both of the testicles fail to drop into the normal place in the scrotum, a condition called undescended testis occurs.

Undescended testis is one of the most common malformations and occurs in about 4 out of every 100 newborn boys. Usually, for about 75 percent of these children, the testicles will drop on their own during the first three to six months of life.

If the testicles don't drop on their own, these boys will need treatment. An undescended testicle should be brought down into the scrotum as early as possible, preferably before the child is one year old. This is thought to preserve the function of the testicle with regard to fertility.

What Problems Can Undescended Testis Cause?

An undescended testis that remains outside the scrotum throughout childhood may result in impaired or abnormal testicular development which could result in future infertility.

Another concern is an increased risk of tumor development in the undescended testis during early adulthood though this is an uncommon occurrence. In addition, most undescended testicles are associated with a congenital hernia and are more prone to injuries than a testicle located within the scrotal sac.


Surgery is performed to bring the testicle down into the scrotal sac and to prevent or lessen the likelihood of associated problems. Additionally, congenital hernias are corrected at the same time.

Surgery at the age of 1 year is now recommended and should allow for maximum preservation of fertility and may reduce the risk of developing testicular tumors later in life. Furthermore, surgery at this age allows for a normal male appearance before school age.