Compared with the general population, women who have never conceived appear to have a slightly increased risk of ovarian cancer (about 1.6 times the rate). Because it is thought that many of these women have also used fertility medications, it has been hypothesized that a link might exist between fertility medications and this particular cancer. A number of studies have been conducted since 1992 when this concern was first raised. None have found an association between fertility medications and higher risk of ovarian or between IVF treatment itself and higher risk of ovarian cancer. Preliminary results from an ongoing National Institutes of Health study likewise suggest no association between fertility medications and ovarian, uterine or breast cancer.

It is possible that this association is due not to the use of fertility medication, but to the fact that this population of women has never undergone childbirth. Findings from the National Institutes of Health and others suggest that pregnancy or some component of the childbearing process may in fact protect directly against ovarian cancer.