Cumulative live birth rates of 31 478 untested embryos from 11 463 women challenge traditional recurrent implantation failure definitions.

This article investigates whether the cumulative live birth rate (cLBR) plateaus after multiple consecutive transfers of untested embryos in assisted reproductive technology (ART). Analyzing data from 11,463 women undergoing 31,478 embryo transfers at Ghent University Hospital between 2010 and 2022, the study found that cLBR continues to increase with each additional blastocyst transfer, reaching 68.3% after six and 78.0% after ten transfers, without evidence of a plateau. Key factors influencing outcomes include maternal age, embryo quality, ovarian stimulation response, and blastocyst formation rate, with older women and poor responders requiring more transfers to achieve comparable success. The findings suggest that repeated embryo transfers can yield substantial chances of live birth, supporting a patient-tailored approach to managing recurrent implantation failure rather than a fixed definition based on a set number of failed transfers.