Undescended testicles, also known as cryptorchidism, is a fairly common and normally painless congenital condition in which one or both of a baby’s testicles (testes) have not moved into the proper position. One to 2 percent of male infants are affected.

Before a baby boy is born, the testicles form in the child’s abdomen. During the third trimester, the testicles travel from the abdomen, down the groin and into the scrotum (the sack of skin beneath the penis). An undescended testicle doesn’t complete the descent process. The testicle may be located anywhere from the abdomen to the groin and may affect one or both testicles.

Premature babies are affected by undescended testicles at a higher rate. The more premature your baby is, the higher the chance of having an undescended testicle.

In some cases — about 20 percent of affected boys — an undescended testicle will descend (or “drop”) on its own within the child’s first six months of life. Those that don’t will require surgery.

Symptoms:

In a baby affected by undescended testicles, one or both of his testicles either appear to be missing or cannot be felt in the scrotum. If both testicles are undescended, the scrotum will look unusually small and flat. If only one testicle is affected, the scrotum may look lopsided.

If your baby’s testicle appears to be “sometimes there and sometimes not,” we call that testicle retractile. It’s a normal condition that requires no treatment.

Causes:

Experts have yet to identify any single cause of undescended testicles. The following factors may interfere with the normal descent and development of the testicles:

• abnormal anatomy
• hormonal problems
• environmental influences

Treatment:

Surgery is highly recommended in order to reduce the risk of cancer or infertility, to improve your son’s body image through adolescence and adulthood, and to reduce long-term effects and the risk of cancer or infertility. In most cases, doctors(andrology surgeon) are able to repair an undescended testicle with a single, simple operation at around 12 months of age.

What are the complications associated with surgery?

Complications from surgery are relatively rare, but in some cases can include bleeding and infection. The most common complication — which is still quite rare, is when the moved testicle goes back up into the groin. In this case, doctors will need to perform another surgery. In very rare cases, a testicle can lose its blood supply, which will render it nonviable. It will then become scar tissue. But again, this is very rare.

Your son may feel some discomfort after his operation, but most boys feel better after about a day. Your doctor will probably recommend that your son avoid sitting on riding toys for about two weeks in order to prevent injury to the testicle. You can expect annual follow-up examinations so the doctor can check that the testicle is growing normally.

What is the long-term outlook for children with undescended testicles?

Undescended testicles may increase the risk of infertility, especially if both testicles are affected. However, boys who have one undescended testicle tend to father children at the same rate as those who are not affected by the condition at all.

Boys who have two undescended testicles — a much lower percentage of patients — do have a significantly lower fertility rate. A child with undescended testicles is slightly more prone to develop testicular cancer, even after corrective surgery. However, surgery performed before puberty may reduce the risk of developing cancer.

Parents should know that cases of cancer related to undescended testicles are rare. Having the surgery is important in that the testicle is located where a young man can palpate a mass if it should develop.