Oocyte-mediated repair of sperm DNA fragmentation: a critical determinant of embryo viability

DNA repair capacity is a critical biological process for maintaining genomic integrity in cells. However, certain cells, such as spermatozoa, possess limited DNA repair ability and depend on the oocyte for this function during fertilization. Among the various types of DNA damage, single- and double-strand sperm DNA fragmentation has emerged as a key factor influencing embryo development and clinical outcomes. Improperly repaired DNA fragmentation can result in developmental delays, embryo arrest or chromosomal abnormalities. This review explores the capacity of the oocyte to repair sperm DNA damage, and how maternal age affects this critical function. Through a structured literature review, the mechanisms involved in oocyte-mediated DNA repair are described and their clinical implications are evaluated. Findings indicate that oocyte quality, which diminishes with age, significantly impacts the efficiency of DNA repair processes, thereby influencing embryo viability and pregnancy success. While younger oocytes can partially compensate for sperm DNA fragmentation, aging oocytes show reduced repair capacity, contributing to poor reproductive outcomes. These insights emphasize the need for novel reproductive strategies aimed at enhancing oocyte quality and repair efficiency.