Infertility is fairly common. After one year of having unprotected sex, about 15 percent of couples are unable to get pregnant. About a third of the time, infertility can be traced to the woman. In another third of cases, it is because of the man. The rest of the time, it is because of both partners or no cause can be found, termed unexplained infertility. According to The American Society for Reproductive Medicine (ASRM), infertility is the inability to conceive after 12 months of unprotected intercourse. This means that a couple is not able to become pregnant after a year of trying. However, for women aged 35 and older, the inability to conceive after 6 months is generally considered infertility. ASRM concur that about one-third of infertility cases can be attributed to male factors and about one-third to factors that affect women. For the remaining one-third of infertile couples, infertility is caused by a combination of problems in both partners or in about 20 percent of cases, is termed unexplained. Causes of Infertility