IUI and IVF for unexplained subfertility: where did we go wrong?

IUI is a first-line treatment for couples with unexplained or mild male subfertility and has become one of the most widely used fertility-enhancing treatments. The results of a recent trial comparing IVF to IUI, demonstrating similar live birth rates, have been used to build a case supporting the effectiveness of IUI. Yet, this conclusion might be somewhat premature, as the superiority of neither IUI nor IVF over no treatment has ever been proven. The evidence on the effectiveness and safety of IUI and IVF has been evaluated in two Cochrane reviews which both suggested that there is insufficient evidence to conclude that IUI or IVF is effective compared to sexual intercourse in couples with unexplained subfertility. Recommendations for clinical practice have been given in the most recent National Institute for Health and Care Excellence fertility guideline that advises not to offer IUI any longer and suggests 2 years of sexual intercourse followed by IVF. This recommendation has generated an ongoing debate, with only 4% of all gynecologists in the UK discontinuing the use of IUI. We feel that it is high time to provide proper scientific evidence for the effectiveness of IUI, or lack thereof, and invite the medical community to start RCTs comparing IUI to sexual intercourse.