Stimulated intra‐uterine insemination is not a natural choice for the treatment of unexplained subfertility

Helping couples to choose appropriate therapy for their unexplained subfertility demands a review of evidence for treatment benefit and harm, in the context of both patients' and clinicians' experience and perspective. Ovulation induction (OI) with clomiphene (CC) or gonadotrophin (FSH) and intrauterine insemination (IUI) are often chosen before resorting to IVF. The appropriateness of starting with these low and intermediate intensity treatments is supported by evidence that CC/IUI increases cycle fecundity two- to three-fold, and FSH/IUI, three- to five-fold over the baseline chance of pregnancy in this patient group. While both OI/IUI and IVF have adverse effects which deserve vigorous attention, particularly multiple pregnancy and ovarian hyperstimulation syndrome (OHSS), the balance between benefits and costs often favours OI/IUI. The cost per live birth and potential for OHSS appears lower with OI/IUI, and the proportion of multiple pregnancies similar to that seen with IVF. For these as well as physical and spiritual reasons, OI/IUI is often a natural starting point for couples, especially when female age and duration of subfertility are favourable.