Comparing the pregnancy rates of one versus two intrauterine inseminations (IUIs) in male factor and idiopathic infertility

Purpose : To compare the effectiveness of double IUI with single IUI in male factor and idiopathic infertility patients undergoing controlled ovarian hyperstimulation (COH). Methods : A prospective randomized study of 1257 COH-IUI cycles was performed. Total 1270 patients with mild or moderate male factor infertility (n = 776) and idiopathic infertility (n = 494) were enrolled in this study, and 767 with male factor infertility and 490 with idiopathic infertility completed clomiphene citrate (CC)/human menopausal gonadotrophin (hMG) COH cycles and IUI. Categorized on the basis of the causes of infertility (male factor, M; idiopathic infertility, I), patients were randomized into one of the following groups: Single IUI group (M-1/I-1) received single insemination 34 h post hCG administration, and double IUI group (M-2/I-2) received two inseminations 18-24 and 36-48 h post hCG injection, respectively. Results : The overall pregnancy rates were 15.43%. Pregnancy rate for single and double IUI group was 11.06 and 19.87% (p < 0.05), respectively. There was a significant statistical difference in cycle fecundity between M-1 and M-2 group (11.34% vs. 24.93%, p < 0.05), and between I-2 and M-2 group (11.93% vs. 24.93%, p < 0.05), but there was no significant difference between I-1 and I-2 (10.53% vs. 11.93%, p > 0.05). Conclusions : Double IUI increases the pregnancy rate significantly in patients with male factor infertility, and single IUI acts as efficient as double IUI in patients with idiopathic infertility.