Sperm deoxyribonucleic acid damage and repair

A greater proportion of inseminated sperm population with fragmented deoxyribonucleic acid (DNA), in either natural service or assisted reproductive technology, has been associated with adverse reproductive outcomes, including abnormal embryonic development and failure of implantation, increasing pregnancy loss and reducing pregnancy rates. However, attempts to establish a causal relationship between sperm DNA damage and pregnancy success have often resulted in conflicting findings. Practical issues include accurate measurement of sperm DNA damage and the necessity to reduce impacts of iatrogenic damage. Sperm DNA repair mechanisms in oocytes and embryos are likely important in addressing sperm DNA damage, promoting normal embryo development, and enhancing reproductive outcomes. However, poor reproductive outcomes are likely caused by unrepaired sperm DNA damage exceeding a critical threshold and adversely affecting embryo development. This review reports sperm DNA damage and repair mechanisms.