Infertility is usually defined as the inability to become pregnant after one year of vaginal intercourse without birth control.
Infertility affects about 10% of couples in their reproductive age. Approximately one-third of infertility cases can be attributed to a fertility issue with the woman; one-third with the man; and one-third with either both partners or the cause of the infertility is never found.
People shouldn't assume that they or their partners are infertile until they've tried and failed to conceive for at least 6 months if the female partner is 35 years or older, or for at least one year if the female partner is less than 35 years of age. If you are still unable to get pregnant after this time, check with your doctor. Fortunately, it's not uncommon for couples to suddenly conceive a child after years of trying unsuccessfully without treatment.