Free centrifuge sorting for sperm separation improves intracytoplasmic sperm injection outcomes: A systematic review and meta-analysis

In assisted reproductive technology, spermatozoa must be separated from seminal fluid to achieve optimal fertilization capacity. Conventional separation techniques frequently result in elevated reactive oxygen species production and iatrogenic injury due to repeated cell centrifugation. The aim of this systematic review and meta-analysis was to evaluate the effects of free centrifuge sorting (FCS) techniques on intracytoplasmic sperm injection (ICSI) outcomes. A comprehensive literature search was conducted using PubMed, Scopus, Web of Science, and Cochrane databases. The meta-analysis adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses Protocols (PRISMA-P) guidelines. All eligible studies were selected using the population, intervention, comparison/comparator, outcomes, and study design (PICOS) methodology. The primary outcomes assessed were fertilization rate (FR), the high-quality embryo rate, implantation rate (IR), and clinical pregnancy rate (CPR). The study is registered in PROSPERO under registration number CRD42023415532. After screening 306 records for eligibility, three studies were ultimately included in the analysis. Our results demonstrate that following ICSI, a very brief period of abstinence significantly increased IR and CPR. However, no significant differences were observed for FR. The FCS technique yielded spermatozoa of superior biological quality following removal of seminal samples, and this purified sperm population improved reproductive outcomes in ICSI programs.