Men's Health: Testicle size matters in men with vein abnormality

A generally harmless enlargement of veins in the scrotum has been linked with low sperm count in men whose testicles are smaller than normal due to changes in blood flow.

This vein enlargement, called a varicocele (pronounced VAIR-ik-oh-seel), can cause pain or discomfort and has been linked by some researchers with infertility, but many cases aren't even noticed. In some instances, the testicle is smaller on the side of the scrotum that contains the varicocele. An outpatient surgical procedure can correct the problem when needed.

Among men seeking treatment for possible infertility, having two small testicles due to varicoceles signals an increased likelihood of low sperm count, according to researchers at the University of California at San Francisco.

Dr. Thomas Walsh and his colleagues measured sperm counts and testicle size in 247 men with varicoceles, finding that men with two small testicles were 10 times more likely to have a low sperm count than men without changes in testicle size and nine times more likely to have a low sperm count than men with just one small testicle.

"This information allows us to better counsel our patients and may allow us to direct our efforts toward a better understanding of how varicoceles may act to impair semen parameters," Walsh says.