What is the clinical impact of the endometrial receptivity array in PGT-A and oocyte donation cycles?

To evaluate the influence of the endometrial receptivity array (ERA) test on the implantation rate (IR) and pregnancy rate (PR) in patients with previous failed euploid embryo transfers (Euploid-ET) or oocyte donation embryo transfers (Donor-ET). Single-center retrospective study of patients with ≥ 1 previous failed Euploi-ET (n = 24) or ≥ 2 failed Donor-ET (n = 32) who underwent an ERA test and a post-ERA Euploid-ET/Donor-ET between 2012 and 2018. Controls were patients with ≥ 1 previously failed Euploid-ET (n = 119) or ≥ 2 failed Donor-ET (n = 158) who underwent Euploid-ET/Donor-ET during the same period without performing an ERA test. Only blastocyst stage embryos were included. IR/PR was compared between the post-ERA ET and the last ET in the control group. There was no statistically significant difference regarding IR [55.6% (34.6–76.5%) vs. 65.0% (56.9–73.1%)] nor PR (58.3% vs.70.6%, p = 0.238) in the Euploid-ET ERA vs. Euploid-ET control groups. In the Donor-ET arm, both IR [26.8% (12.3–41.4%) vs. 57.2% (50.1–64.3%)] and PR (34.4% vs. 65.2%, p = 0.001) were significantly lower in the ERA group. Multivariate analysis confirmed that performing an ERA test did not influence the PR in the Euploid-ET arm and was associated with a diminished PR in the Donor-ET arm. In the ERA group, 41.1% patients were non-receptive (NR). No significant difference was found regarding IR/PR in NR vs. receptive patients in both Euploid-ET/Donor-ET arms. In our sample, the performance of an ERA test did not improve pregnancy outcomes. Future prospective studies in larger samples are needed to confirm the role of the ERA test in Euploid-ET/Donor-ET.