Effects of advanced selection methods on sperm quality and ART outcome

In assisted reproductive technology (ART), the role of spermatozoa has evolved over the years. In the past, early methods of selecting sperm for ART only focused on selecting motile and morphologically normal appearing sperm. It has become evident that these methods are inefficient in identifying the most suitable sperm for fertilization. Novel methods have thus been created to identify highly motile, morphologically normal, viable non-apoptotic spermatozoa with intact membranes and high DNA integrity for use in ART. These advanced methods of selection utilize our knowledge of unique characteristics of sperm, such as sperm surface charge, the presence of hyaluronic acid binding sites on sperm, sperm ultramorphology, markers of apoptosis and zona pellucida binding on sperm. These methods have shown potential promise in improving ART outcomes. Future developments may include Raman spectroscopy, confocal light absorption and scattering spectroscopic microscopy, and polarization microscopy. While these novel techniques have potential, they come with a cost burden and further studies are required to demonstrate their impact on ART outcomes. Furthermore, clinicians and human reproductive scientists need to continue to gather knowledge about human fertilization and determine the most physiological methods of sperm selection.