SUPEROVULATION IN THE TREATMENT OF UNEXPLAINED INFERTILITY

Unexplained infertility occurs commonly after a standard diagnostic assessment.1 Although there is no definitive diagnosis, and treatment-independent pregnancy occurs frequently, many couples wish to have treatment. One choice is superovulation treatment, which may augment normal mechanisms of conception or correct undetected ovulatory dysfunction. Superovulation is defined as the ovulation of a greater than normal number of ova, usually the result of the administration of exogenous gonadotropins.2 Clomiphene citrate (CC) is also associated with a dose-dependent rise in the number of recruited ovarian follicles, suggesting that the mechanism of a CC effect in the treatment of unexplained infertility could also be through a similar process.3 The efficacy of superovulation treatment with respect to conception can best be judged against a background on the prevalence and prognosis of unexplained infertility and a discussion of possible underlying reasons for the failure to explain infertility. This qualitative review is followed by a quantitative review of the literature on unexplained infertility and conception, and an interpretation of the implications of the published data for clinical practice. The definition of unexplained infertility is the most controversial aspect of this subject, however, and that is discussed at the outset.