Infertility is a condition of the reproductive system in which a couple has been unable to become pregnant after one year of unprotected, well-timed intercourse (six months if the woman is over 35) or  the woman has been unable to carry a pregnancy to a live birth. For women 40 years  and older, consult a fertility specialist after 3 months of trying to become pregnant.Infertility is a medical problem that affects both women and men. Approximately 40 percent of infertility is due to female factors, 40 percent is due to male factors. The remaining 20% of cases are either a result of both partners or for unknown reasons.