Objective: To study the true prevalence of recurrent implantation failure.
Design: Retrospective cohort study.
Setting: A private assisted reproductive technology center.
Patient(s): Women (n = 4,429) with anatomically normal uterus who underwent up to three consecutive frozen euploid single embryo transfers (FE-SETs) were included in the study. Cycles with donor eggs or gestational carriers were excluded.
Main outcome measure(s): Cumulative outcomes from these cycles were analyzed. A logistic regression model was used to assess the differences of outcomes between first, second, and third FE-SET and a Kaplan-Meier curve as used to analyze cumulative implantation rate.
Result(s): The mean age of the patients included in the study was of 35.4 years. The sustained implantation rates of the first, second, and third FE-SET were 69.9%, 59.8%, and 60.3% per transfer, respectively. The cumulative sustained implantation rate after up to three consecutive FE-SET was 95.2%. The live birth rates after the first, second, and third FE-SET were 64.8%, 54.4%, and 54.1% per transfer, respectively. The cumulative live birth rate after up to three consecutive FE-SET was 92.6%. The miscarriage rate after observing a positive heartbeat was not different between the first (7.2%), second (8.8%), and third (12.7%) FE-SET.
Conclusion(s): Our findings suggest that true recurrent implantation failure is rare. For those patients with the ability to make euploid blastocysts, <5% would fail to achieve a clinical pregnancy with three embryos transferred. It remains to be further investigated whether this threshold identifies a truly recalcitrant group or simply a statistical certainty based on random variation.
Keywords: Recurrent implantation failure; euploid blastocysts; frozen embryo transfer; preimplantation genetic testing for aneuploidy.
Copyright © 2020 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.