What Medically Assisted Reproduction Should Be Offered in Unexplained Infertility?

Abstract

Conflict of Interest: BWM is supported by a NHMRC Investigatorgrant (GNT1176437). BWM reports consultancy and travel support from Merck, Guerbet and Organon and research funding from Merck. In up to half of all couples who seek medical assistance for infertility a direct cause for their inability to conceive cannot be identified and they are therefore labelled as having unexplained infertility. Unexplained infertility is characterized by normal ovulation, tubal patency, and a normal (or slightly deviant) semen analysis in the male partner according to WHO-criteria. The causes of unexplained infertility remain, as determined by its definition, largely unknown. Available treatments for unexplained infertility include intrauterine insemination (IUI) with ovarian hyperstimulation, in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), but also tubal flushing or lifestyle interventions. Treatments like IUI and IVF might on one hand be effective because they increase the number of possible conceptions, for example by creating multiple follicles or embryos, but they also might overcome an unknown barrier for conception. Since, in couples labelled with unexplained infertility natural conception by definition never can be excluded, the prognostic profile of couples for such natural conception is instrumental. I will argue that understanding of prognosis for natural conception should be one of the cornerstones for the management of infertility. If the prognosis for a ‘spontaneous pregnancy’ within a reasonable time frame is high enough, it might be justified to delay treatment in these couples for some time. After that, IUI should be the treatment of first choice.