Patients and Methods: Fifty-six infertile women participated in this randomized clinical trial after referring to Mahdiyeh hospital, Tehran, Iran and undergoing IUI treatment in 2017. Participants were randomly divided into nimodipine (n=34) and placebo (n=22) groups. The demographic and clinical profile of women were collected using a predesigned checklist. In the nimodipine group, 30 mg tablets were given to patients three times daily for 2 days. Finally, the serum levels of LH and estradiol were measured before and after the intervention.

Results: Based on the results, the LH surge was observed in 8 (34.8%) women in the placebo group (P=0.04) while it was not detected in 29 (78.4%) women in the nimodipine group. There were no statistical differences in the serum levels of estradiol and LH between the 2 groups before the intervention. The serum levels of estradiol in both groups increased after intervention although this increase was not significant. Eventually, no statistical difference was found between the 2 groups in terms of fertility rate.

Conclusions: In general, nimodipine can significantly reduce premature LH surge in patients undergoing IUI compared to the placebo group.