Live birth rates after blastocyst transfers performed by fellows

Abstract

To evaluate live birth rates following embryo transfer performed Reproductive Endocrinology and Infertility fellows compared to attending physicians. Retrospective Cohort Study. Institutional Review Board approval was obtained. Women undergoing blastocyst transfer between 1/2015 and 1/2018 were reviewed. Cycle characteristics and outcomes were compared between embryo transfers performed by fellows and attending physicians. A sample size of 750 embryo transfers was required to detect a 10% difference between groups, with 80% power and alpha of 0.05. A total of 940 blastocyst transfers were included; 254 performed by five fellows and 686 performed by ten attending physicians. There were no differences in the mean age, anti-mullerian hormone (AMH) levels or rate of preimplantation genetic testing for aneuploidy (PGT-A) testing between groups (Table). The afterload technique was utilized more frequently by fellows, 95.2% (242/254) vs. 87.8% (602/686), P=0.0004. A stylet was used less frequently by fellows, 0.4% (1/254) vs. 4.5% (31/686), P=0.0008. The pregnancy rate in the fellow group was not significantly different from the pregnancy rate in the attending group; 72.8% (185/254) among fellows versus 67.6% (461/686) among attending physicians, p= 0.27. There were also no significant differences in the live birth rate between groups, 51.6% (131/254) versus 49.4% (339/686) respectively, P=0.61. After controlling for embryo transfer technique and stylet use, there remained no difference in pregnancy outcomes. The average pregnancy rate among fellows performing their first 20 embryo transfers was 67.4% (58/86), and was no different from the average pregnancy rate among attending physicians, 67.6% (461/686) P=1.0. Embryo transfer success rates were not different between fellows and attending physicians. Barriers to fellowship training in embryo transfer should be evaluated and addressed, as there was no compromise in pregnancy rates, even in the first twenty embryo transfers performed.Table 1Group Characteristics (N=940 transfers)Fellow ET (N=254)Attending ET (N=686)p-valueAge (SD), yr34.1 (3.4)34.1 (3.6)1.00AMH (SD), ng/mL3.9 (3.1)3.8 (3.3)0.68% PGS testing22.0% (56/254)22.6% (155/686)0.93% Fresh Transfer41.3% (105/254)34.4% (236/686)0.06Afterload technique95.2% (242/254)87.8% (602/686)0.0004Stylet0.4% (1/254)4.5% (31/686)0.0008Blood on catheter tip4.3% (11/254)6.8% (47/686)0.17Embryo Retained0% (0/254)0.3% (2/686)1.0# Embryos Transferred (SD)1.2 (0.5)1.3 (0.5)0.1Pregnancy Rate72.8% (182/254)67.6% (464/686)0.27Miscarriage Rate18.9% (48/254)16.8% (115/686)0.44Live Birth Rate51.6% (131/254)49.4% (339/686)0.61 Open table in a new tab