Infertility is “a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse (and there is no other reason, such as breastfeeding or postpartum amenorrhoea).

Primary infertility is infertility in a couple who have never had a child.

Secondary infertility is failure to conceive following a previous pregnancy.

Infertility may be caused by a problem in the man or woman, but often there is no obvious underlying cause.