Rethinking insemination for good-prognosis couples: the emotional and ethical burden of cryopreserved embryos never transferred

Abstract

The cumulative live birth rate in assisted reproductive technology is directly proportional to oocyte yieldtherefore, ovarian stimulation seeks to optimize the oocyte yield from treatment. Despite the inevitable attrition during the culture, some couples may encounter an excess of embryos, resulting in the dilemma of how to manage their surplus embryos. The fate of surplus and unneeded embryos is contingent upon the legal framework and couples' preferences. A paradigm shift from surplus embryo cryopreservation to surplus oocyte cryopreservation prior to insemination may address these concerns. The availability of euploid blastocysts serves as the nearest surrogate marker for the likelihood of a live birth in subsequent embryo transfers, and current predictive models can calculate the average number of oocytes required to obtain one or more euploid blastocysts based on female age. Given the challenges of customizing ovarian stimulation to yield a precise number of oocytes, limiting oocyte insemination and cryopreserving the surplus oocytes may effectively prevent the creation of unwanted embryos. This 'smart insemination-preserving the rest' strategy will not eliminate the need for gamete storagenonetheless, it may reduce the number of possibly unwanted embryos stored and address the complex issue of their management.