Infertility refers to an inability to conceive after having regular unprotected sex. Infertility can also refer to the biological inability of an individual to contribute to conception, or to a female who cannot carry a pregnancy to full term. In many countries infertility refers to a couple that has failed to conceive after 12 months of regular sexual intercourse without the use of contraception.
Studies indicate that slightly over half of all cases of infertility are a result of female conditions, while the rest are caused by either sperm disorders or unidentified factors.
According to The Mayo Clinic, USA:
About 20% of cases of infertility are due to a problem in the man.
About 40% to 50% of cases of infertility are due to a problem in the woman.
About 30% to 40% of cases of infertility are due to problems in both the man and the woman.