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 (≥17 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.