Magnetic-Activated Cell Sorting (MACS) for Annexin V versus Density Gradient Centrifugation (DGC) + Swim Up (SU): Comparison of Embryological Outcomes in Couples that have undergone ICSI

Spermatogenesis, the biological process by which male gametes (spermatozoa) are produced, forms one of the most fundamental yet intricate mechanisms of human reproduction. It starts before puberty and continues throughout the male’s lifetime, allowing for the ongoing production of spermatozoa capable of fertilizing the oocyte. However, sperm quality is not constant across the lifespan. It varies with age and is further influenced by environmental exposures, lifestyle choices, and medical interventions, making sperm quality assessment a vital part of male fertility evaluation. Semen analysis remains the standard method for assessing sperm parameters, including motility, concentration, morphology, and viability. While informative, this evaluation provides only a limited overview of fertilization potential. To address this limitation, complementary functional assays have been developed to explore deeper aspects of sperm physiology. Among these are tests that measure oxidative stress and DNA fragmentation, both of which directly relate to sperm integrity and embryo development. The increased recognition of such parameters has emphasized the need for advanced sperm selection methods that aim to improve outcomes in assisted reproductive technologies. Magnetic-Activated Cell Sorting (MACS) using Annexin V represents an innovative approach. By selectively removing apoptotic spermatozoa characterized by the externalization of phosphatidylserine, MACS enriches the sample with sperm of higher viability and lower DNA fragmentation. This refinement not only enhances the chances of successful fertilization but also significantly improves the developmental competence of embryos. Importantly, evidence from laboratory studies demonstrates that the use of MACS with Annexin V leads to superior embryological outcomes compared to conventional Density Gradient Centrifugation (DGC). Specifically, couples whose samples were processed with both methods showed a statistically significant improvement in Day 5 embryo quality when MACS was applied. These findings emphasize the relevance of adopting novel sperm selection strategies in clinical practice. The integration of MACS into ART protocols addresses critical limitations of traditional semen preparation techniques, offering a more targeted approach to selecting functionally competent sperm. Overall, continuous refinement of laboratory methods is essential to maximize the effectiveness of ART, ultimately contributing to higher fertilization success rates and improved embryo quality for couples undergoing assisted reproduction.