Increased sperm count in 25 cases of idiopathic normogonadotropic oligospermia following treatment with tamoxifen.

Twenty-five subfertile men, all presenting with idiopathic normogonadotropic oligospermia, were treated with tamoxifen (20 mg/day) for 4 to 12 months. Semen analysis was performed twice before treatment and at least twice after 3 to 12 months of treatment. In 14 patients, serum luteinizing hormone (LH), serum follicle-stimulating hormone (FSH), and plasma testosterone (T) were assayed before treatment, then again after 2 weeks and 12 weeks of treatment. Semen volume, sperm motility, and sperm morphologic characteristics were not modified by tamoxifen. Conversely, a twofold increase of both the mean sperm concentration and the mean total sperm count per ejaculate was observed during treatment (P less than 0.001). Mean values of T, LH, and FSH increased during treatment, but the difference was only significant for T (P less than 0.001) and FSH (P less than 0.05). Ten pregnancies (40% of cases) were reported during the 161 months of treatment.