Testicles, also called testes, are male reproductive organs that are typically located in the scrotum. Normally, during late pregnancy, the fetal testicles drop down from the abdomen, through the groin and into the scrotum. Undescended testes occur when one or both testicles don't drop down into the scrotum before birth.
Also called cryptorchidism, this is the most common birth defect of the male genitals, affecting one out of every 125 baby boys. The condition is more common in premature and low-birth weight babies.
Usually, the testicle will descend by itself within the first six months after birth. If not, the baby will need an outpatient surgery to put it in the proper position. If a testicle remains undescended, the child will not be able to perform a testicular self-exam to screen for cancer as an adult.
Undescended testicles don't produce any symptoms. The only sign of the condition is that the health care provider is unable to feel the testicle in the scrotum during examination.
Undescended testes are usually diagnosed at birth, or during a well baby exam, when one or both of the testes can't be felt when the scrotum is examined. The scrotum may appear flat and small. The child will be reexamined at 5 to 6 months to see if it has descended.
Sometimes an undescended testicle is confused with a retractile testicle, which is a normally descended testicle that's pulled out of the scrotum by an overactive cremasteric muscle reflex — an automatic reflex that occurs when skin on the front inner thigh is stroked. In this case, the health care provider will be able to feel the testicle in the scrotum. Retractile testicle is more common in boys between the ages of 2 and 7, it doesn't require treatment.
In most children, the testicle descends within six months of birth without any treatment. If it has not descended by 6 months of age, the child will need surgery.
Surgery is performed at our outpatient surgery center. We will make an incision in the groin on the affected side. Once the undescended testicle is found, it's pushed down into the scrotum and stitched into the proper position. If we can't feel where the testicle is located, we will look for it with a special scope — a tube with a miniature camera on it that allows us to see inside the body. Then, we use the scope to place the testicle in the scrotum.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.