EFFECT OF TIMING BY ENDOMETRIAL RECEPTIVITY TESTING VS STANDARD TIMING OF FROZEN EMBRYO TRANSFER ON LIVE BIRTH IN PATIENTS UNDERGOING IN VITRO FERTILIZATION: A RANDOMIZED CLINICAL TRIAL
Frozen embryo transfers have gained popularity in recent years, and in 2020, 75% of fertility treatment cycles involved embryo cryopreservation. This randomized clinical trial was initiated to determine if the use of endometrial receptivity assay (ERA) to time frozen euploid blastocyst transfer increases the probability of live birth. Study participants were planning to undergo IVF, PGT-A testing, and frozen embryo transfer. Participants were aged 30 to 40 years old at the time of egg retrieval and likely to produce at least 1 euploid blastocyst. 767 patients were randomized to one of two study arms: use of ERA to time frozen embryo transfer, or standard timing for embryo transfer. Results from the study indicate that live birth rate is not improved with the use of ERA testing, compared to standard timing of frozen embryo transfer (58.5% vs. 61.9%, respectively; difference, -3.4% [95% CI, -10.3% to 3.5%]; rate ratio [RR], 0.95 [95% CI, 0.79 to 1.13]; P = 0.38). Similarly, clinical pregnancy rate was not improved with the use of ERA testing, compared to the control group (68.8% vs. 72.8%, respectively; difference, −4.0% [95% CI, −10.4% to 2.4%]; RR, 0.94 [95% CI, 0.80 to 1.12]; P = .25).