Use of the endometrial receptivity array to guide personalized embryo transfer after a failed transfer attempt was associated with a lower cumulative and per transfer live birth rate during donor and autologous cycles

To determine whether personalized embryo transfer (pET) guided by endometrial receptivity array (ERA) test improves reproductive outcomes for fresh embryo transfers (fsETs) or frozen embryo transfers (FETs) during autologous and donor cycles.A retrospective, observational, multicenter cohort study.University-affiliated in vitro fertilization center.The study included patients with a single previous failed transfer and yielded 3,239 autologous transfers and 2,133 donor transfers. Among autologous transfers, 255 were pET guided by ERA; among unguided autologous transfers, 1,122 and 1,862 transfers involved fresh or previously frozen embryos, respectively. Among donor transfers, 319 were ERA-guided; among unguided donor transfers, 1,175 and 639 involved fsETs or FETs, respectively.None.Primary outcomes were live birth rate per embryo transfer and cumulative live birth rate on consecutive transfers until live birth or cessation of pregnancy. Secondary outcomes were implantation, pregnancy rate, clinical pregnancy rates per embryo transfer, and miscarriage rate per pregnancy.During both autologous or donor transfers, live birth rate and cumulative live birth rate were higher in FET and fsET than in pET groups, even with euploid transfers. Logistic regression analysis, considering possible confounders, indicated patients receiving pET had poorer outcomes than those undergoing FET and fsET in autologous and donor cycles. Implantation, pregnancy, and clinical pregnancy rates were lower in patients undergoing pET.Using ERA to guide pET during either autologous or donor cycles after a failed transfer attempt did not improve reproductive outcomes. Conversely, worse outcomes were detected when ERA was used.