Healthy live birth following embryo transfer of a blastocyst of tetrapronuclear (4PN) origin: a case report.

This article focuses on a unique case of successful live birth following the transfer of an embryo derived from a tetrapronuclear (4PN) zygote, which is typically considered abnormally fertilized and discarded due to risks of ploidy abnormalities. Using targeted next-generation sequencing (tNGS) for preimplantation genetic testing (PGT), the embryo was found to be diploid and euploid, leading to the birth of a healthy child with normal development at four years of age. The report highlights that embryos from zygotes with abnormal pronuclei numbers, including 3PN and 4PN, can sometimes be diploid and viable, suggesting that PGT combining aneuploidy and ploidy analysis may allow rescue of such embryos, especially in cases with limited embryo availability. This case underscores the potential clinical value of advanced genetic testing and time-lapse embryo monitoring in expanding embryo selection criteria for patients with infertility challenges.