Drug therapy for idiopathic male infertility: rationale versus evidence

About half of all infertile men who seek treatment have no specific cause that can be determined for the seminal abnormality. These men are often subject to a number of medical therapies with doubtful efficacy. We reviewed the rationale on which these therapies are advised and determined whether sufficient medical evidence exists to justify their use.

A literature search was performed using MEDLINE/PubMed, focusing on publications of the last 20 years of drug therapies for idiopathic male factor infertility. Therapies for specific abnormalities such as hypogonadism were excluded. Basic science, in vitro and animal studies suggesting the mechanism of action for male infertility were evaluated as the rationale part of the review, while controlled and uncontrolled human clinical trials were reviewed as evidence for drug use.

There is no evidence in support of androgens and gonadotropins for enhancing male fertility. These agents may instead act as contraceptives with significant side effects. There is insufficient evidence regarding the role of antiestrogens, aromatase inhibitors and antioxidants. No drug therapy has proved to be clearly beneficial for idiopathic oligoasthenoteratospermia.

Drug therapy for idiopathic male infertility is at best empirical. There is no clear benefit of using any medication in these patients. Moreover, androgens should not be used because they may actually suppress spermatogenesis.