For 15 to 30% of infertile couples, no etiology can be found, leading to the diagnosis of "unexplained infertility". The aim of our study was to identify prognostic factors for live birth following in vitro fertilization (IVF) for these couples.A retrospective, monocentric study on a cohort of couples undergoing IVF for unexplained infertility with the woman aged≤40 years old. Primary analysis compared couples with a live birth following IVF versus childless couples following IVF.Between January 2014 and December 2018, 104 couples were included, 196 transvaginal oocyte pickup were performed, followed by 234 embryo transfers (fresh or cryopreserved) which resulted in 43 deliveries. The cumulative live birth rate was 40.4% per couple. Before IVF attempts, no clinical or paraclinical prognostic factors between the two groups was observed. However, multivariate analysis showed several biological factors of good prognosis in course of treatment, such as a higher number of mature oocytes and better quality embryos in "live birth" group.For a couple, the chances of having a child following IVF unexplained infertility are 40.4%. However, no clinical characteristic enabled us to identify favourable or unfavourable prognosis factors before starting ART. The prognostic factors identified during IVF cycle are interesting to advise or not to pursue IVF.
