Couples with unexplained subfertility and unfavorable prognosis: a randomized pilot trial comparing the effectiveness of in vitro fertilization with elective single embryo transfer versus intrauterine insemination with controlled ovarian stimulation

Objective To evaluate the effectiveness of IVF with elective single embryo transfer (IVF-eSET) vs. IUI with controlled ovarian stimulation (IUI-COS) as an alternative treatment to reduce the risk for a multiple pregnancy. Design Randomized pilot trial. Setting Three academic and six teaching hospitals in the Netherlands. Patient(s) Couples with unexplained or mild male subfertility and an unfavorable prognosis for natural conception. Intervention(s) One cycle of IVF-eSET or three cycles of IUI-COS. Main Outcome Measure(s) Ongoing pregnancy per couple. Result(s) We randomly allocated 116 women to IVF-eSET (n = 58) or IUI-COH (n = 58). There were 14 ongoing pregnancies (24%) in the IVF-eSET group and 12 pregnancies (21%) in the IUI-COS group (relative ratio 1.17; 95% confidence interval 0.60–2.30). There were two twin pregnancies in the IVF-eSET group (14%) and two twin pregnancies and one triplet pregnancy in the IUI-COH group (25%). Conclusion(s) In patients with unexplained or mild male subfertility and a poor prognosis for natural conception, one cycle of IVF-eSET might be as effective as three cycles of IUI-COS as primary treatment. Elective single embryo transfer does not seem an effective strategy in preventing multiple pregnancies in this particular population. In the future a strict SET policy (i.e., compulsory SET) might be an option. Our trial provides evidence for the feasibility and highlights the importance of a large definitive trial to determine the effectiveness and side effects of both strategies.