THE CLINICAL USE OF ENDOMETRIAL RECEPTIVITY ANALYSIS (ERA®) AND THE EFFECTS ON IMPLANTATION RATES IN WOMEN WITH PRIOR FAILED TRANSFERS

Abstract

Endometrial receptivity is thought to be an important cause of implantation success or failure. ERA® (Endometrial Receptivity Analysis) analyzes the transcription profile of luteal phase endometrium (in a natural or programmed cycle) to determine its receptivity. ERA® results purport to allow physicians to personalize frozen embryo transfer (FET) protocols to transfer embryos during the “receptive” window, and thus increase implantation (IR) and pregnancy (PR) rates. In this study, we aimed to (1) evaluate the utilization of ERA® in a single large private ART practice, (2) for patients who had “non-receptive” ERA® results, determine if customized modifications of FET protocols according to ERA® results have led to changes in IR and PR in subsequent FETs. A retrospective cohort analysis. We reviewed records of patients who had an ERA® between 2014 to 2019 at our IVF center. All ERA® cycles were programmed cycles with an average progesterone duration of 133 (98-168) hours before the endometrial biopsy. Patient demographics, previous FET data, ERA® results, and outcome of subsequent FETs were analyzed. Data analysis was performed using Excel and MedCalc.org and SciStat.com. 173 patients completed an ERA®. The age was 39±4.781 years, with 82% of patients having had at least one prior FET (0-7). 8.6% had a chart diagnosis of uterine factor, 7.5% with endometriosis, 11% with adenomyosis, and 15% of patients had fibroids. The average peak endometrial thickness was 9.8±2.0 mm for the ERA® cycle and 9.9±2.1 mm during the first subsequent FET. Of all ERA®s completed, 40% (N=69) patients were receptive, 43% (N=74) pre-receptive (recommended transfer 24 hrs later), 14.45% (N=25) early receptive (12 hrs later), 2.3% (N=4) late receptive (12 hrs earlier), and one patient was post-receptive. 10% completed a second ERA® due to an invalid biopsy sample, and only one patient completed three ERA®s. Overall FET PR in this cohort of patients pre-ERA® was only 5% (16/320). The overall PR post-ERA® was 36% (63/171) with an odds ratio of 11.1 (95% CI 6.1-20.0). Pre-ERA® IR of autologous euploid embryos was 6.3% (11/176). The post-ERA® IR of autologous euploid embryos was 42% (47/112) with an odds ratio of 10.8 (95% CI 5.3-22.2). For the non-receptive groups (both pre- and post-receptive), the pre-ERA® PR was 5.5% (10/180) and post-ERA® PR was 36% (35/97) with an odds ratio of 7.9 (95% CI 3.3-18.8). The pre-ERA® IR of autologous euploid embryos was 8.7% (9/104). The post-ERA® IR was 42% (24/56) with an odds ratio of 9.6 (95% CI 4.5-20.53). For the receptive groups, the pre-ERA® PR was 4.3% (6/140), and post-ERA® PR was 37% (28/74) with an odds ratio of 13.6 (95% CI 5.3-34.9). The receptive group had a pre-ERA® IR of autologous euploid embryos of 2.8% (2/71), and a post-ERA® IR of 41% (23/55) with an odds ratio of 24.8 (95% CI 5.5-111.6). 60% of patients had non-receptive ERA®s. While non-receptive patients had increased implantation and pregnancy rates post-ERA®, similar improvements were also seen in receptive patients making it difficult to draw the conclusion that ERA® was clinically beneficial.