Routine endometrial receptivity array in first embryo transfer cycles does not improve live birth rate

Objective: To compare the live birth rate between patients who undergo personalized embryo transfer (pET) after endometrial receptivity array (ERA) versus frozen embryo transfer (FET) with standard timing in first single euploid FET cycles. To report the rate of displacement of the window of implantation (WOI) in an infertile population without a history of implantation failure. Design: Prospective cohort study of patients who underwent their first single euploid programmed FET. Setting: Private fertility clinic. Patient(s): Patients who underwent first autologous single euploid programmed FET between January 2018 and April 2019. Intervention(s): Endometrial biopsy with ERA followed by pET as indicated. Main Outcome Measure(s): Live birth rate and rate of receptive and nonreceptive ERA. Result(s): A total of 228 single euploid FET cycles were included in our analysis. Of those, 147 (64.5%) were ERA/pET cycles, and 81 (35.5%) were standard timing FET cycles. Endometrial receptivity array was receptive in 60/147 (40.8%) and nonreceptive in 87/147 (59.2%) patients. Nonreceptive ERAs were prereceptive in 93.1% of cases. The live birth rate did not differ between patients who underwent FET with standard timing and patients who underwent ERA/pET, 45/81 (56.6%) and 83/147 (56.5%), respectively. Conclusion(s): Our data do not support the routine use of ERA in an unselected patient population undergoing first autologous single euploid programmed embryo transfer. (Fertil Sterile 2021;115:1001?6. ?2020 by American Society for Reproductive Medicine.) El resumen est? disponible en Espa?ol al final del art?culo.