As a baby boy grows inside his mother's womb, his testicles typically form inside his abdomen and move down (descend) into the scrotum shortly before birth. But in some cases, that move or descent doesn't occur, and the baby is born with a condition known as undescended testicles (or cryptorchidism).

Cryptorchidism is the most common genital abnormality in boys, affecting approximately 30% of baby boys born prematurely and about 4% born at term.

In about half of the babies, the undescended testicles move down or descend on their own by the sixth month of life. If descent doesn't happen by then, it's important to get treatment because testicles that remain undescended may be damaged, which could affect fertility later or lead to other medical problems.

Causes and risk factors of cryptorchidism

Cryptorchidism is not considered a serious medical condition although it should be corrected early. When the testes remain in the scrotum there is a risk that fibrous proteins such as collagen may begin to deposit around the undescended testicles and impair their function.

The scrotum, because it is exposed to the air, keeps the testes 1 to 2 degrees cooler than other organs. This temperature difference enhances the creation and maturation of sperm. The temperature difference is lost when the testes remain in the abdomen.

Men with cryptorchidism are thought to be at greater risk of testicular cancer and fertility problems. Microscopic changes have been noted in testicles when left in the abdomen for longer than a year although the implications of such changes are not clearly understood. In addition, testicles lodged in the abdomen tend to be close to the surface and are at greater risk of being physically injured. Appearance may also become a concern.

Diagnosis of cryptorchidism

Doctors usually diagnose cryptorchidism during a physical exam at birth or at a check-up shortly after. In 7 of 10 boys with an undescended testicle, it can be located or "palpated" on examination by the paediatric specialist.

In 3 of 10 boys, the testicle may not be in a location where it can be located or palpated, and may appear to be missing. In some of these cases, the testicle could be inside the abdomen. In some boys with a "non-palpable" testicle, however, the testicle may not be present because it was lost while the baby was inside the womb.

In some boys, the testicles may appear to be outside of the scrotum from time to time, which can raise the concern of an undescended testicle. Some of these boys may have the condition known as retractile testes. This is a normal condition in which the testes reside in the scrotum but on occasion temporarily retract or pull back up into the groin.

There is no need to treat a retractile testicle, since it is a normal condition, but it might require examination by a child specialist to distinguish it from an undescended testicle.

Treatment of cryptorchidism

Treatment may be hormonal, surgical or a combination of both. Some testicles will respond to intra-muscular injections of the hormone HCG (human chorionic gonadotropin) by completing their descent. Orchiopexy, an operation designed to bring an undescended testicle into the scrotum, is accomplished through either an open procedure or laparoscopically.

In the open procedure, a small incision in made in the groin to locate and manipulate the undescended testicle and another is made in the scrotum. The testicle is moved into the scrotum and a few sutures are placed to stabilize it and hold it in place. Laparoscopic orchiopexy is essentially the same procedure conducted with a slender viewing scope inserted in the abdomen.

Although both procedures are outpatient procedures, laparoscopic diagnoses and surgery uses smaller incisions resulting in minimal blood loss and more rapid recovery. Both open and laparoscopic orchiopexy procedures have a very high success rate.