The use of birefringence for human spermatozoa selection before intracytoplasmic sperm injection to improve artificial reproductive technology outcomes: A systematic review and meta-analysis

In an era where male infertility poses significant challenges for many couples, intracytoplasmic sperm injection (ICSI) is becoming increasingly common. Microscopic evaluation of sperm head morphology can contribute to the development of healthier embryos. A comprehensive literature search was conducted using the PubMed, Scopus, Web of Science, and Cochrane databases. A meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) for randomized controlled trials. Eligible studies were selected based on the PICOS (Population, Intervention, Comparison/Comparator, Outcomes, Study type) model. The pregnancy outcomes considered after artificial reproductive technology (ART) procedures included the fertilization rate (FR), high-quality embryo rate (HQER), implantation rate (IR), and clinical pregnancy rate (CPR). This study was registered on PROSPERO (CRD42023423108). Of 105 records evaluated, three studies met the inclusion criteria. Our analysis indicated that birefringence sperm selection significantly improved HQER and IR after ART, although no significant differences were observed for FR and CPR. The use of birefringence for sperm selection in ICSI cycles may represent a straightforward strategy to improve ART outcomes, particularly for couples with abnormal sperm parameters.