#371 : Immunological Analysis of Endometrial Receptivity: A New Hope for Patients with Recurrent Implantation Failures

Background and Aim: Recurrent implantation failures (RIF) remain always a strong problem for all IVF teams. Our ART Center started in 2015 and quickly we wanted to focus on implantation failure. After 2 or 3 embryo transfers without pregnancy, guidelines provide to perform exams such as karyotypes, Anti phospholipid, thrombophilia, uterine Doppler, hysteroscopy, endometrial biopsy with CD 136, laparoscopy, sperm DNA Fragmentation. However, a large part of these failures remains unexplained. Following the studies performed in France by N. Lédée in 2013, this study evaluates the results of a new exploration based on immunological analysis of endometrial receptivity.

Methods: This study is proposed, after other explorations already done, for patients with 6 or more embryos D3 or 3 embryos D5 transferred without pregnancy. Such an analysis is achieved on endometrial biopsy performed in middle luteal phase and sent to MatriceLab (Paris)

Immunological exploration is based on uNK count (uterine Natural Killer cells) and cytokines expression. According to these parameters, “individualized” care is proposed to patient for next embryo transfers to correct the disorder identified by analysis.

Results: From 2016 to 2020, 114 biopsies have been performed and sent to MatriceLab. 112 were suitable for analysis. According with results, 4 main profiles have been isolated: Normal immunity (22,3%) Dysregulation immunity (77,7%). Low local immune activation (25%). Over local immune activation (40,2%). “Mix” profile (12,5%) 95 patients have been performing FET following the analysis. Mean age 32.6 ±3.6 years. Mean number of transfers before biopsy 3.9 ±1.6. Mean number of embryos previously transferred 9.6 ±4.4. Deliveries in normal immunity group: 33% (n=6). Deliveries in dysregulation group treated with adapted protocol: 53,2% (n=40)

Conclusions: This pregnancy rate is much better than usual pregnancy rate expected after six embryos D3 or three embryos D5 transferred without pregnancy.