Abstract: The review included 10 RCTs (757 couples). The quality of the evidence was low or very low for all comparisons. The main limitations in the evidence were failure to describe study methods, serious imprecision and inconsistency. IUI versus TI (five RCTs) Two RCTs compared IUI with TI in natural cycles. There were no data on live birth or OHSS. We found no evidence of a difference in pregnancy rates (2 RCTs, 62 couples: odds ratio (OR) 4.57, 95% confidence interval (CI) 0.21 to 102, very low quality evidence; there were no events in one of the studies). Three RCTs compared IUI with TI both in cycles with OH. We found no evidence of a difference in live birth rates (1 RCT, 81 couples: OR 0.89, 95% CI 0.30 to 2.59; low quality evidence) or pregnancy rates (3 RCTs, 202 couples: OR 1.51, 95% CI 0.74 to 3.07; I2 = 11%, very low quality evidence). One RCT reported data on OHSS. None of the 62 women had OHSS. One RCT compared IUI in cycles with OH with TI in natural cycles. We found no evidence of a difference in live birth rates (1 RCT, 44 couples: OR 3.14, 95% CI 0.12 to 81.35; very low quality evidence). Data on OHSS were not available. IUI in cycles with OH versus IUI in natural cycles (five RCTs) We found no evidence of a difference in live birth rates (3 RCTs, 346 couples: OR 1.34, 95% CI 0.77 to 2.33; I2 = 0%, very low quality evidence) and pregnancy rates (4 RCTs, 399 couples: OR 1.68, 95% CI 1.00 to 2.82; I2 = 0%, very low quality evidence). There were no data on OHSS. IVF versus IUI in natural cycles or cycles with OH (two RCTs) We found no evidence of a difference in live birth rates between IVF versus IUI in natural cycles (1 RCT, 53 couples: OR 0.77, 95% CI 0.25 to 2.35; low quality evidence) or IVF versus IUI in cycles with OH (2 RCTs, 86 couples: OR 1.03, 95% CI 0.43 to 2.45; I2 = 0%, very low quality evidence). One RCT reported data on OHSS. None of the women had OHSS. Overall, we found no evidence of a difference between any of the groups in rates of live birth, pregnancy or adverse events (multiple pregnancy, miscarriage). However, most of the evidence was very low quality. There were no studies on IUI in natural cycles versus TI in stimulated cycles, IVF versus TI, ICSI versus TI, ICSI versus IUI (with OH) or ICSI versus IVF. We found insufficient evidence to determine whether there was any difference in safety and effectiveness between different treatments for male subfertility. More research is needed.

Plain-language summary: We searched medical databases for randomised controlled trials (clinical studies where people are randomly put into one of two or more treatment groups) investigating male subfertility. We found 10 randomised controlled trials, all comparing different treatments for couples with male subfertility, with a total of 757 couples. The studies evaluated the following treatment options: timed intercourse (TI; where sex occurred at a recommended time in the menstrual cycle) (with or without OH), IUI (with or without OH), IVF and ICSI. The evidence was current to April 2015. We were mainly interested in how many women had live births and OHSS. We found no evidence of a difference in live birth or pregnancy rates between treatments. We also found no evidence of a difference between any of the groups in rates of adverse effects (multiple pregnancy, miscarriage). Available data on OHSS was too limited for us to draw any conclusions. Most of the evidence was of low or very low quality. The main limitations were failure to describe study methods, small sample sizes and inconsistency in how trials were conducted. Evidence was available for only six of the 14 comparisons that we evaluated. More research is needed.