The effect of clomiphene citrate on different sperm parameters and serum hormone levels in preselected infertile men: a controlled double-blind cross-over study.

In order to try to clarify the often supposed stimulating effect of clomiphene citrate on spermatogenesis a controlled double-blind cross-over trial was used. 30 pre-selected normogonadotropic infertile men were given 50 mg clomiphene citrate daily or placebo in a double-blind cross-over fashion for three months, each treatment period being separated by three to four months. On clomiphene treatment the median sperm count increased from 13.3 to 28.7 mill/ml (P < 0.001). During the placebo treatment schedules the median sperm count remained unchanged (P < 0.05). The increases of FSH, LH, testosterone, and oestradiol were highly significant (P < 0.001) during the clomiphene treatment but during placebo treatment the median hormone levels did not change (P < 0.05). Three pregnancies occurred due to clomiphene treatment and one occurred during placebo treatment.