Recombinant FSH versus clomiphene citrate for ovarian stimulation in couples with unexplained infertility and male subfertility undergoing intrauterine insemination: a randomized trial

Purpose To compare the efficacy of clomiphene citrate (CC) and recombinant FSH (rFSH) protocols in ovarian stimulation (OS)/intrauterine insemination (IUI) cycles for couples with unexplained infertility or male subfertility. Methods One hundred and eighty-nine patients with unexplained or male subfertility were randomized to treatment with 100 mg/day CC for 5 days (93 patients) or rFSH with starting dose of 75-100 IU daily (96 patients). The main outcome measurement was ongoing pregnancy rate (OPR). Results The number of preovulatory (a parts per thousand yen17 mm) follicles on the day of hCG administration was significantly greater in the rFSH group than in the CC group (1.7 vs. 1.4, P = .01). Multifollicular growth was observed in 35.1% in the CC group and 54.8% in the FSH group (P = .01). The OPR per cycle was 9.6 and 15.6% for CC and rFSH groups, respectively (P = .31). Conclusions Recombinant FSH is superior to CC for enabling multifollicular development in OS/IUI cycles of unexplained and male subfertile couples. Although this finding did not lead to a statistically significant superiority of rFSH in terms of clinical outcomes, the presence of relative increase by 62.5% in OPR with rFSH may be regarded as a clinically significant trend.