Live birth after transfer of a single euploid vitrified-warmed blastocyst according to standard timing vs. timing as recommended by endometrial receptivity analysis.

OBJECTIVE: To determine whether endometrial receptivity analysis (ERA) improves live births in patients with and without a history of unsuccessful frozen embryo transfers (FETs).
DESIGN: Retrospective cohort study.
SETTING: Large reproductive center. PATIENT(S): Patients with and without ERA before euploid single FET were included in the analysis. INTERVENTION(S): Subjects in the exposed group underwent ERA and ERA-timed FETs. Subjects in the unexposed group followed a standard protocol FET without ERA. Outcomes were compared between nonreceptive and receptive subjects undergoing an ERA-timed FET and between ERA-timed vs. standard protocol FETs. MAIN OUTCOME MEASURE(S): The primary outcome was a live birth; secondary outcomes were biochemical and clinical pregnancy rates. RESULT(S): A total of 307 ERA-timed FETs and 2,284 standard protocol FETs were analyzed. One hundred twenty-five patients (40.7%) were ERA receptive, and 182 (59.3%) were ERA nonreceptive. After adjusting for the number of the previously failed FETs, there was no difference in the proportion of receptive and nonreceptive ERA results. There were no statistically significant differences in live births in patients with ERA-receptive vs. ERA-nonreceptive results (48.8% and 41.7%, respectively; adjusted odds ratio 1.17; 95% CI, 0.97-1.40). There were no statistically significant differences in live births in patients with or without ERA testing results before FET (44.6% and 51.3%, respectively; adjusted odds ratio 0.87; 95% CI, 0.73-1.04). CONCLUSION(S): Patients with an increasing number of previous failed euploid FET cycles are not at an increased risk of a displaced window of implantation. Patients categorized as receptive vs. nonreceptive and those without ERA testing results have comparable FET success rates.