Infertility is defined as an inability to conceive after a year of regular, unprotected intercourse. The male partner or female partner, or both may account for this condition. It is an impairment; it is not the same as sterility, which means that reproduction is physically impossible.

Female infertility may be because of irregular or absence of ovulation, blocked fallopian tubes or endometriosis. Male infertility is usually due to a low sperm count or other deficiency in the spermatozoa.