A narrative review of sperm selection technology for assisted reproduction techniques.

Background and Objective: In-vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) has become increasingly prevalent even in cases without significant male factor infertility; however, stagnant live-birth rates, both nationally and internationally, have driven more research into sperm selection. To date, nothing has replaced swim-up and density-gradient preparation methods and therefore we sought to review the state of the science. Methods: A PubMed search was performed between years of 1989 and 2024 for English research articles reporting data on sperm selection technology in assisted reproductive technology. Key Content and Findings: IVF with ICSI is increasingly prevalent even in men with normal semen parameters. Despite technologic advances and widespread use, reproductive outcomes with ICSI have been stagnant. This market for opportunity growth has allowed for sperm selection techniques to grow exponentially with heterogeneity in utilization and a paucity of positive reproductive outcomes. Swim-up and density-gradient centrifugation remain the most utilized sperm selection techniques. Various future technologies show promise including epigenetics, sperm biomarkers and a potential role of artificial intelligence; however, more research is needed. Conclusions: Given unchanged IVF success rates, sperm selection technologies hold promise to improve reproductive outcomes beyond traditional ICSI. At present, no technique has shown superiority to swim up and density centrifugation.