Q. My new baby was born with an undescended testicle. What should we do?
A. When a baby boy is an embryo in his mother's womb, the testicles form in the lower part of the abdomen (the pelvis). In the weeks before the baby is born, the testicles move down out of the pelvis into a sac (the scrotum) that lies outside the body.
In about one-third of premature and approximately 3 percent of full-term male infants, one or both of the testicles have not completely descended into the scrotum by the time the child is born. The scrotum appears visibly underdeveloped or smaller on the affected side. This is known as an undescended testicle.
In most cases, the testicle descends spontaneously during the first 3 to 6 months of life.
If your son's testicle has not descended by the time he's 6 to 9 months old, you should have a pediatric urologist examine him. In most cases, the doctor will be able to feel the testicle above the scrotum, which means it's likely to drop into the scrotum in the coming months. (I've put an illustration of the typical sites of an undescended testicle on my website, AskDoctorK.com.)
If the doctor cannot find and feel the testicle, he or she may do a diagnostic laparoscopy to locate it. In this procedure, the doctor will insert a video camera through a small incision to look inside your son's body.
An undescended testicle increases the risk of infertility. That's because the testicles produce sperm, and normal sperm production requires the cooler temperature found in the scrotum. An undescended testicle also increases the risk of testicular cancer, hernias and testicular twisting.
An empty scrotum can also cause psychological stress as a boy gets older. For these reasons, early treatment is important.
Most cases can be corrected with a surgical procedure called orchiopexy. The surgeon brings the testicle down into the scrotum through the normal abdominal opening. He or she then stitches it into its proper place in the scrotum. Occasionally, more extensive surgery is required.
Hormone injections may be tried before surgery. The hormones stimulate the testicles to produce more testosterone, which may help the testicle move down into the scrotum.
In some cases of undescended testicle, the testicle never formed when the baby was an embryo, or formed abnormally. An abnormal testicle should be removed surgically. Testicles that never form, or form abnormally, are rare. But if they occur, and the testicle is removed, your son can be given a testicular implant when he is older so that his testicles appear normal. And the healthy testicle may well produce enough sperm so that infertility is not a problem.
There often are no problems from an undescended testicle. Still, the safest course is the one I recommend above.
• Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com.