The effectiveness of clomiphene citrate in LH surge suppression in women undergoing IUI: a randomized controlled trial

Objective: To study the effectiveness of clomiphene citrate (CC) in preventing a premature LH surge during controlled ovarian stimulation in women undergoing assisted reproduction. Design: Prospective, randomized, controlled trial. Setting: University hospital. Patient(s): Two-hundred thirty couples with mild male factor, or unexplained infertility. Intervention(s): Couples were randomized to receive human menopausal gonadotrophins (hMG) followed by CC or hMG alone until the day of hCG. Main Outcome Measure(s): The primary outcomes were the incidence of a clinical pregnancy and premature LH rise. Secondary outcomes were the E-2 levels, number of mature follicles, and endometrial thickness as determined on the day of hCG. Result(s): The number of patients who had a premature LH surge was significantly lower in the hMG + CC group (5.45% vs. 15.89%). Additionally, the mean E-2 levels (pg/mL) and the number of mature follicles were also significantly higher in the hMG + CC group (360.3 +/- 162.9 vs. 280 +/- 110.0 and 2.4 +/- 0.97 vs. 1.3 +/- 1.1, respectively), although there was no significant difference regarding number of canceled cycles, endometrial thickness, or clinical pregnancy rate. Conclusion(s): The addition of CC to hMG has been proven to be effective in reducing premature LH surges without compromising the pregnancy rate. (Fertil Steril (R) 2010; 94: 2167-71. (C) 2010 by American Society for Reproductive Medicine.)