How Common Is Male Infertility?
Infertility is defined clinically in women and men who cannot achieve pregnancy after 1 year of having intercourse without using birth control, and in women who have two or more failed pregnancies.
A complete lack of sperm occurs in about 10% to 15% of men who are infertile. A hormone imbalance or blockage of sperm movement can cause a lack of sperm. In some cases of infertility, a man produces less sperm than normal. The most common cause of this condition is varicocele (pronounced VAR-i-koh-seel), an enlarged vein in the testicle. Varicocele is present in about 40% of men with infertility problems.
