Meta-correlation of Sperm Morphology and DNA Fragmentation Index

The 6th WHO guidelines for human semen examination recommend advanced semen analysis, such as the sperm DNA fragmentation index (DFI), to evaluate male factor infertility, as oxidative stress in the male reproductive system can damage sperm plasma membranes and compromise DNA integrity. Although sperm DFI was known to be associated with pregnancy probability, its examination is often limited by unavailability and high costs. In contrast, basic semen analysis, which includes sperm morphology assessment, is routinely performed, widely available, and cosf-effective. This systematic review and meta-analysis aimed to evaluate the correlation between sperm morphology and DNA Fragmentation Index (DFI) to improve diagnostic and clinical applications. Relevant studies were retrieved from MedLine, Web of Science, Scopus, EBSCO, and ProQuest, using keywords related to the correlation between sperm morphology and DFI. Correlation analyses were conducted using a random-effects model to calculate r-values for normal and abnormal sperm morphology with DFI. This meta-analysis showed an inverse correlation between normal sperm morphology and DFI with r: -0.30 and a positive correlation between abnormal sperm morphology and DFI with r: 0.39. Specifically, the head deformities had stronger correlation with DFI compared to neck and tail deformities. This study underscores the potential to predict DFI from sperm morphology results in settings where DFI testing is unavailable.