Infertility, or a couple’s inability to conceive, is often discussed primarily as being a women’s issue. Male infertility, however, may be much more common than most people think.

The National Institutes of Health estimates infertility affects up to 15 percent of couples. About 11 percent of women of reproductive age have experienced fertility issues, compared to 9 percent of men.

Typically, couples younger than 30 and in generally good health have a 40 to 60 percent chance of conceiving after three months of having unprotected sex. However, after a year of unprotected sex, 12 to 15 percent of couples find they are unable to conceive, and that figure drops to 10 percent after two years of trying.

It’s estimated that the cause of infertility lies with the man in one-third of the cases, with the woman in one-third of the cases, and is either unidentifiable or because of both partners in the other one-third of cases.

Definition & causes of male infertility

Infertility can be related to sexual function or to semen and sperm quality. Some contributing factors to those issues include