Outcomes of embryo transfers performed by Reproductive Endocrinology and Infertility fellows vs. faculty: an 11-year retrospective review

Clinical pregnancy rate and live birth rate after embryo transfers performed by fellows vs. faculty physicians were not statistically different. Among fellows, these outcomes did not differ across fellowship years.

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VOLUME 117, ISSUE 1, P115-122


Colleen M. Miller, M.D., Amy L. Weaver, M.S., Yulian Zhao, M.D., Ph.D., Samir N. Babayev, M.D. 



To compare the clinical pregnancy rate (CPR) and live birth rate (LBR) of embryo transfer episodes (ETEs) performed by Reproductive Endocrinology and Infertility fellows vs. those of ETEs performed by faculty physicians.


Retrospective cohort analysis.


Academic reproductive endocrinology and infertility practice.


In total, 3,073 ETEs for 1,488 unique patients were performed by fellows or faculty physicians between January 2009 and January 2020.



Main Outcome Measure(s)

Clinical pregnancy rate and LBR.


Fifteen fellows performed 1,225 (39.9%) of 3,073 ETEs after completing 30 mock transfers. On comparing outcomes among fellowship years (FY1, FY2, and FY3), CPR (44.1% vs. 43.2% vs. 45.7%, respectively, P = .83) and LBR (39.1% vs. 38.1% vs. 38.4%, respectively, P = .97) were not significantly different. Fellowship year 1 fellows’ initial 30 ETEs vs. all the remaining FY1 ETEs had a significantly higher CPR (48.1% vs. 40.5%, respectively, P = .030) and LBR (45.4% vs. 34.3%, respectively, P = .001). There were no significant differences between faculty versus fellow ETEs in terms of CPR (43.0% vs. 45.0%, respectively, P = .30) or LBR (37.3% vs. 39.8%, respectively, P = .16), even after adjusting for patient age, body mass index, primary infertility diagnosis, autologous vs. donor oocyte, fresh vs. frozen embryo, number of embryos transferred, type of transfer catheter, and year of transfer (P = .32 for CPR, P = .22 for LBR).


Appropriately trained FY1 fellows had success rates maintained throughout all FYs. There were no significant differences in clinical outcomes between fellow- and faculty-performed transfers. These data demonstrated that allowing fellows to perform live embryo transfers is not detrimental to clinical outcomes.

Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders.