Ask the Expert: What Are Varicoceles and What Role Do They Play in Male Infertility?

A little-known condition, varicoceles are often harmless, but there are times when varicoceles can impact a man’s fertility.

Similar to varicose veins you might get in your legs, varicoceles are enlarged veins inside the scrotum. Sometimes, they can also be seen and felt through the scrotal skin surface. The condition is rare and often harmless, but it can be painful and, in severe cases, cause infertility.

Mary Samplaski, MD, urologist at USC Urology at Keck Medicine of USC and assistant professor of clinical urology at the Keck School of Medicine of USC, is an internationally recognized leader in male infertility, andrology and microsurgery. We asked her to explain varicoceles and their role in male infertility.

What causes varicoceles?

Veins work against the pull of gravity and carry oxygen-poor blood away from the testicles. Consequently, these veins have a tendency to dilate and enlarge.

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In some men, the condition is harmless. In others, the pooling of blood in the testicles causes heat and toxin buildup, affecting sperm production and function. Because the blood drainage pathways differ on each side of the body, varicoceles are more common in the left testicle.

Who’s at risk for varicoceles?

About 10 out of 100 men have varicoceles, and doctors cannot predict who will have fertility problems because of the condition. In fact, eight out of 10 men who have a varicocele do not have fertility problems. However, of those tested for infertility, four out of every 10 men will have the condition. In fact, scrotal varicoceles have been found to be the most common identifiable and surgically correctable factor that contributes to poor testicular function and decreased semen quality.

How are varicoceles treated?

At USC Urology, we recommend microsurgical varicocele repair (varicocelectomy) to stop further deterioration of sperm production and improve sperm quality to fertile levels. Using an operative microscope during surgery, we identify and treat the precise veins that are dilated. The surgery is done under general anesthetic and takes about two hours. Men go home the same day.

Is there a cure for varicoceles?

There is a small chance that surgery will not correct the problem, but two-thirds of men find that their semen parameters improve. Additionally, recent data show that varicocele repair improves reproductive outcomes, including pregnancy rates after intrauterine insemination, in vitro fertilization and intracytoplasmic sperm injection.

by Heidi Tyline King

If you are in the Los Angeles area, you can schedule an appointment with one of the specialists at USC Urology of Keck Medicine by calling (800) USC-CARE (800-872-2273) or by visiting