New horizons in human sperm selection for assisted reproduction

Abstract

Male infertility is a commonly encountered pathology that is estimated to be a contributory factor in approximately 50% of couples seeking recourse to assisted reproductive technologies. Upon clinical presentation, such males are commonly subjected to conventional diagnostic andrological practices that rely on descriptive criteria to define their fertility based on the number of morphologically normal, motile spermatozoa encountered within their ejaculate. Despite the virtual ubiquitous adoption of such diagnostic practices, they are not without their limitations and accordingly, there is now increasing awareness of the importance of assessing sperm quality in order to more accurately predict a male’s fertility status. This realization raises the important question of which characteristics signify a high-quality, fertilization competent sperm cell. In this review, we reflect on recent advances in our mechanistic understanding of sperm biology and function, which are contributing to a growing armory of innovative approaches to diagnose and treat male infertility. In particular we review progress toward the implementation of precision medicine; the robust clinical adoption of which in the setting of fertility, currently lags well behind that of other fields of medicine. Despite this, research shows that the application of advanced technology platforms such as whole exome sequencing and proteomic analyses hold considerable promise in optimizing outcomes for the management of male infertility by uncovering and expanding our inventory of candidate infertility biomarkers, as well as those associated with recurrent pregnancy loss. Similarly, the development of advanced imaging technologies in tandem with machine learning artificial intelligence are poised to disrupt the fertility care paradigm by advancing our understanding of the molecular and biological causes of infertility to provide novel avenues for future diagnostics and treatments.

Resolving Secondary Infertility: A Case Report of the Successful Treatment of Sperm DNA Fragmentation Through the Physiological Intracytoplasmic Sperm Injection Method

“…Other advanced methods of sperm selection include intracytoplasmic morphologically selected sperm injection, magnetic-activated cell sorting, and zeta potential sperm selection. Recent analyses have found that there is insufficient evidence to determine whether these techniques lead to better clinical outcomes, such as higher live birth rates [ 7 , 17 ].…”

“…However, there are no additional recognized risks associated with PICSI, either for individuals who undergo fertility treatment or for children born through such treatment [ 6 ]. Hyaluronic acid (HA) receptors on plasma membranes are a maturation marker, and sperm that can bind immobilized HA in vitro are of higher quality [ 7 ]. The sperm selection process using the HA binding system can be applied in a laboratory setting and imitate the natural selection of male gametes cost-effectively.…”

Effects of Heparan sulfate acetyl-CoA: Alpha-glucosaminide N-acetyltransferase (HGSNAT) inactivation on the structure and function of epithelial and immune cells of the testis and epididymis and sperm parameters in adult mice

“…Fish sperm head plasma membranes have been demonstrated to contain syndecan (transmembrane heparan sulfate proteoglycan), which may play a role in fertilization [ 145 ]. Thus, HS may be on the sperm plasma membrane and released during transit along the epididymis, where sperm protein loss is substantially more predominant than sperm protein gain [ 146 , 147 ].…”

Combined sperm selection techniques to boost the success of in Vitro Fertilization (IVF) and Intra Cytoplasmic Sperm Injection (ICSI)

“…Infertility affects up to 15% of couples who are of reproductive age, making it a somewhat prevalent condition. Around 30 % of partners who struggle to conceive are thought to be totally at blame, and male factors are also known to play a role in about 50% of all cases of infertility (Nixon et al, 2023). The standard examination of sperm does not accurately predict fertility; it is merely one of many variables.…”