Undescended testicle occurs when one or both testicles fail to move into the scrotum before birth.

Cryptorchidism; Empty scrotum - undescended testes; Scrotum - empty (undescended testes); Monorchism; Vanished testes - undescended; Retractile testes

Most of the time, children's testicles descend by the time they are 9 months old. Undescended testicles are fairly common in infants who are born early (premature infants). It occurs in about 3 - 4% of full-term infants.

Once a testicle has been found in the scrotum, it is considered descended, even if it is temporarily pulled back (retracted) during a later examination.

Some babies have a condition called retractile testes, in which the health care provider sometimes cannot find the testicles. This is due to the muscle reflex that retracts the testicles and the small testicle size before puberty. The testicles will descend at puberty. Surgery is not needed.

Testicles that do not descend by the time the child is 1 year old should be evaluated. Studies suggest that surgery should be done by this age. Surgery can reduce the chances of permanent damage to the testicles, which can lead to fertility problems later in life.

Testicles that do not naturally descend into the scrotum are considered abnormal. An undescended testicle is more likely to develop cancer, even if it is brought down into the scrotum. The other testicle is also more likely to develop cancer, even if it descended properly.

Bringing the testicle into the scrotum can improve sperm production and increases the odds of good fertility. It also allows the health care provider to examine the testicle to detect cancer early.

In other cases, no testicle may be found, even during surgery. This may be due to a problem that occurred while the baby was still developing in the mother (congenital).

There are usually no symptoms, except that the testicle cannot be found in the scrotum (this may be described as an empty scrotum).

An examination confirms that one or both of the testicles are not in the scrotum.

The health care provider may or may not be able to feel the undescended testicle in the abdominal wall above the scrotum.

Usually the testicle will descend into the scrotum without treatment during the child's first year of life. If this does not occur, the child may get hormone injections (B-HCG or testosterone) to try to bring the testicle into the scrotum.

Surgery (orchiopexy) to bring the testicle into the scrotum is the main treatment. Having surgery early may prevent damage to the testicles that can cause infertility.

If the undescended testicle is found later in life, the health care provider may recommend removing it, because it will not work very well and it could develop cancer.

Imaging tests, such as an ultrasound or CT scan, may be done.

Most cases get better on their own, without any treatment. Medicine or surgery to correct the condition is usually successful.

In about 5% of patients with undescended testicles, the testicles cannot be found at the time of surgery. This is called a vanished or absent testis.

• Damage to the testicle from surgery Infertility later in life
• Testicular cancer in both testes

Call your child's health care provider if he appears to have an undescended testicle.

Barthold JS. Abnormalities of the testes and scrotum and their surgical management. In: Wein AJ, ed. Campbell-Walsh Urology.10th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 132.  

Elder JS. Disorders and anomalies of the scrotal contents. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 539.

Wampler SM, Llanes M. Common scrotal and testicular problems. Prim Care. 2010; 37:613-626.