Assessing endometrial receptivity after recurrent implantation failure in euploid embryo transfer: a retrospective study in private clinic

Objective: To analyze whether endometrial receptivity evaluation, prior to euploid embryo transfer, improves the success rate in patients with recurrent implantation failure (RIF). Methods: Retrospective, observational, cross-sectional study, which included couples undergoing assisted reproduction techniques (2021), who experienced RIF after transfer of good quality, euploid blastocysts (analyzed with PGT-A). Three groups were formed, which depended on the result of ERA: 1) Receptive, 2) Pre-receptive and 3) Early receptive. Results: Of the 100% of the patients, 43% presented a normal window of implantation. However, 61.5% showed a higher prevalence of natural killer alterations and 42.8% of thrombophilias. In the case of patients with altered endometrial receptivity, they presented a cumulative implantation rate higher than 70% when correcting controlled ovarian stimulation. Conclusions: More than half of the patients with RIF have a displaced implantation window and may benefit from a personalized adjustment of the endometrial stimulation protocol. Thus, couples with idiopathic RIF or associated with thrombophilias and immunological factors, benefit from the study of endometrial receptivity.