Unexplained recurrent implantation failures: Predictive factors of pregnancy and therapeutic management from a French multicentre study.

INTRODUCTION Recurrent implantation failure is defined as the absence of pregnancy after at least three transfers of good-quality embryos after in vitro fecundation/intracytoplasic sperm injection. AIM The aim of this study was to describe a multicentre cohort of women with unexplained RIF, to analyse the factors associated with clinical pregnancy and to evaluate the immunomodulatory therapies efficacy. METHODS Women were consecutively recruited from university departments with unexplained RIF. RESULTS Sixty-four women were enrolled with mean age 36 ± 3 years. The rates of clinical pregnancy in 64 women were compared in untreated and treated cycles and according to therapies used during the last prospectively followed embryo transfer. A clinical pregnancy after the transfer was noted in 56 % pregnancies on intralipids and in 50 % on prednisone, versus 5 % in untreated ones (p < 0.001). The 340 embryo transfers of these 64 women resulted in 68 clinical pregnancies and 18 live births. Clinical pregnancies were significantly more frequent in treated versus untreated embryo transfers (44 % vs 9 %; p < 0.001) with odds ratio at 8.13 (95 % CI 4.49-14.72, p < 0.0001). Cumulative pregnancy rates were higher for steroid-treated transfers than for untreated transfers when considering overall transfers before and after using steroids and also only those under steroids. Cumulative pregnancy rates were not different from steroid- and intralipid-treated embryo transfers CONCLUSIONS: In this multicentre study of women with unexplained RIF, use of immunomodulatory treatments before embryo transfer resulted in higher clinical pregnancy. Randomised, well-designed studies in well-defined population of RIF women are necessary to confirm our preliminary data.