The beneficial effects of toremifene administration on the hypothalamic-pituitary-testicular axis and sperm parameters in men with idiopathic oligozoospermia.

Objective: To evaluate whether toremifene, a selective estrogen receptor modulator (SERM), has a beneficiary effect on all three main sperm parameters.

Design: Prospective interventional clinical study.

Setting: University hospital.

Patient(s): One-hundred subfertile men with idiopathic oligozospermia.

Intervention(s): Toremifene (60 mg daily) was administered to all men for 3 months. At baseline and at the end of each month, serum concentrations of follicle-stimulating hormone (FSH), testosterone, inhibin B, and sex hormone-binding globulin (SHBG) were measured. At baseline and at the end, semen analysis was performed and sperm concentration, spermatozoal motility and normal sperm forms were determined.

Main Outcome Measure(s): Gonadotropin, testosterone, inhibin-B levels, total sperm count, sperm morphology and motility.

Result(s): Toremifene administration resulted in a significant increase in FSH, testosterone, SHBG, and inhibin B levels, as well as in sperm concentration, percentage motility and normal sperm forms. Twenty-two men's partners achieved pregnancy within 2 months of the end of treatment. At the end of the third month, serum FSH levels were significantly higher in the men whose partners did not achieve pregnancy, and total sperm count and normal sperm forms were significantly lower compared with the group of men whose partners achieved pregnancy.

Conclusion(s): Toremifene administration for a period of 3 months in men with idiopathic oligozoospermia is associated with significant improvements of sperm count, motility, and morphology, mediated by increased gonadotropin secretion and possibly a direct beneficial effect of toremifene on the testes. The above findings are also indicative of a better testicular exocrine (improved sperm parameters) response to treatment in men whose partners achieved pregnancy compared with those who did not. Further randomized, placebo-controlled trials should be conducted to determine whether this particular selective estrogen receptor modulator can be useful as an initial approach in men with oligozoospermia.