Double versus single intrauterine insemination for unexplained infertility: a meta-analysis of randomized trials

OBJECTIVE: To investigate the effect of double versus single intrauterine insemination (IUI) per treatment cycle in women with unexplained infertility.

DESIGN: Meta-analysis of randomized controlled trials.

MAIN OUTCOME MEASURE(S): Clinical pregnancy rates per couple.

INTERVENTION(S): Electronic searches of the Cochrane Central Trials Registry and Medline without year and language restriction through March 2009; hand searching of the abstract books of the European Society of Human Reproduction and Embryology and American Society for Reproductive Medicine annual meetings (2001-2008).

RESULT(S): Six randomized trials, involving 829 women, were included in the analysis. Fifty-four (13.6%) clinical pregnancies were recorded for treatment with double IUI and 62 (14.4%) for treatment with single IUI. There was no significant difference between the single and double IUI groups in the probability for clinical pregnancy (odds ratio, 0.92; 95% confidence interval, 0.58-1.45; P=0.715).

CONCLUSION(S): Double IUI offers no clear benefit in the overall clinical pregnancy rate in couples with unexplained infertility.