Abstract
PURPOSE: Density gradient centrifugation (DGC) enriches motile sperm but may increase sperm DNA fragmentation (SDF), whereas microfluidic sperm sorting devices, such as ZyMōt and CA0, enable centrifugation-free selection with lower SDF. Direct comparisons are limited, and their relative clinical efficacy remains unclear. We compared sperm parameters and SDF after DGC, ZyMōt, and CA0 to evaluate sperm selection performance and assessed the clinical utility of ZyMōt and CA0 based on intracytoplasmic sperm injection (ICSI) outcomes. METHODS: Seventeen semen samples were aliquoted into three groups and processed using DGC, ZyMōt, or CA0. Sperm parameters and SDF were evaluated before and after selection. ICSI was performed using ZyMōt or CA0-selected sperm, inseminating 108 oocytes with ZyMōt and 64 with CA0, followed by the comparative analysis of embryo development. RESULTS: ZyMōt-selected sperm exhibited higher motility, average path velocity, and amplitude of lateral head displacement than DGC (p < 0.01); CA0-selected sperm showed higher linearity and wobble. ZyMōt achieved higher rates of fertilization, blastocyst formation, and good-quality blastocysts, and a lower percentage of poor-quality cleavage-stage embryos than CA0 (all p < 0.05). CONCLUSIONS: ZyMōt demonstrated superior sperm quality compared with DGC and CA0, and favorable ICSI outcomes further support its potential clinical applicability. TRIAL REGISTRATION: The study (H2023-230) was registered in the Japan Registry of Clinical Trials (jRCT) Clinical Trials Registry in Japan (jRCT1040230045).