Double versus single homologous intrauterine insemination for male factor infertility: a systematic review and meta-analysis.

Male factor infertility affects 30%-50% of infertile couples worldwide, and there is an increasing interest in the optimal management of these patients. In studies comparing double and single intrauterine insemination (IUI), a trend towards higher pregnancy rates in couples with male factor infertility was observed. Therefore, we set out to perform a meta-analysis to examine the superiority of double versus single IUI with the male partner's sperm in couples with male factor infertility.