Single versus double intrauterine insemination in stimulated cycles for subfertile couples: a systematic review based on a Cochrane review

BACKGROUND: The objective of this review was to determine, from the best available evidence, the difference in outcome using single versus double intrauterine insemination (IUI) in stimulated cycles for subfertile couples. METHODS: The principles of the Cochrane Menstrual Disorders and Subfertility Group were employed. Randomized controlled trials with a parallel design, comparing single versus double IUI in subfertile couples, would be eligible. The main outcome measures included live birth rate and pregnancy rate per couple (and per cycle). RESULTS: Three studies involving 386 women were included. The results of pregnancy rate per couple, of two studies showed no significant effect of using double insemination [Peto odds ratio (OR) 1.45; 95% confidence interval (CI) 0.78-2.70]. The results of pregnancy rate per cycle of the included studies favoured double insemination, however this is not an eligible outcome measure. CONCLUSIONS: Based on the results of two trials, double intrauterine insemination showed no significant benefit over single IUI in the treatment of subfertile couples with partner semen. There are no meaningful data to offer advice on the basis of this review. A randomized controlled trial of single versus double IUI is justified.