Testicles are part of the male body. They make male hormones and sperm. Usually both testicles are inside the scrotum. While male babies are still growing inside the uterus, their testicles are inside their abdomen. The testicles usually move down into the scrotum just before or just after birth. An undescended testicle is one that did not move down into the scrotum.
Undescended testicles are common in male babies. Up to 30% of boys born early and 3% to 5% of boys born on time have at least one undescended testicle. If your newborn baby has an undescended testicle, it will usually move down on its own in the first few months of life. If this doesn't happen after 3 or 4 months, it may need to be treated by a doctor.
Your doctor can tell whether your baby has an undescended testicle by checking the baby's scrotum. If your doctor can't feel the testicle inside the scrotum, it's called a "nonpalpable" testicle. A nonpalpable testicle might be inside the abdomen, too small to feel or not there at all. It's important to find out which one is the reason. Your doctor may perform an X-ray or ultrasound to locate an undescended testicle.
There are several reasons to treat an undescended testicle. First, undescended testicles may not make sperm. Testicles are in the scrotum because the temperature there is cooler than it is inside the body. A cooler temperature helps the testicles make sperm. A man's ability to make sperm can be lost in early childhood if the testicle doesn't drop down into the scrotum. A baby boy with an undescended testicle can start to lose the ability to make sperm by 12 months of age. Getting the testicle down into the scrotum early in life can help him have a better chance of having children when he grows up.
Second, an undescended testicle is more likely to develop a tumor. Testicular cancer affects one of every 2,000 men with undescended testicles. This rate of testicular cancer is higher than the rate in men whose testicles have dropped naturally. When the testicle is inside the scrotum, a man can easily feel his testicles to check for a tumor, or he can be checked by his doctor. This way, any tumor can be found early, when the cancer is easier to cure.
Treatment for an undescended testicle depends on where it is. Babies who have a testicle that can be felt in the groin (the area where your thigh meets your body) often get an operation called orchiopexy (say: "or-key-oh-peck-see"). Babies who have this operation usually go home the same day. The operation is done through a small cut in the groin. Most babies get better very quickly.
Another treatment is a hormone called hCG. Your doctor might give your child hCG in a shot. HCG helps the testicles make male hormones. A higher level of male hormones might move the testicle down into the scrotum.
If you are an adult with an undescended testicle, moving the testicle to the scrotum probably won't improve your ability to make sperm. So, in adult men an undescended testicle is usually just removed. If you are an older man with an undescended testicle, your doctor can help you decide what to do.
The Undescended Testicle: Diagnosis and Management by SG Docimo, MD, RI Silver, MD, and W Cromie, MD (American Family Physician November 01, 2000, http://www.aafp.org/afp/20001101/2037.html)
Written by familydoctor.org editorial staff