Infertility is defined as the inability to get pregnant after a year of unprotected intercourse. About 40 percent of the time, the diagnosis is due to female infertility; another 40 percent is due to male infertility; the remaining 20 percent is due to a combination of factors from both partners or is “unexplained” – meaning no cause can be found. Human reproduction is remarkably complicated. Several systems of the body must be in sync for the process to culminate in conception and pregnancy. It takes only one seemingly minor situation to disrupt the intricate series of events.

To understand what can go wrong and cause infertility, start by understanding the basics of conception.

The following pages describe some of the more common causes of infertility for  men  and women.