The Efficacy of a Manual Microfluidic Dish Compared with the Discontinuous Gradient Centrifugation Method for Sperm Selection in ICSI Cycles

Introduction: Microfluidic sperm selection systems (MFSSs) have emerged as centrifugation-free alternatives to conventional sperm preparation methods, such as density gradient centrifugation (DGC), which may induce oxidative stress and sperm DNA damage. Although commercial MFSS devices have shown potential benefits, their clinical use is limited by cost and reliance on proprietary systems. Manual MFSS has been proposed as a simplified and cost-effective alternative. However, the clinical effectiveness of MFSS, particularly in relation to embryological and clinical outcomes in intracytoplasmic sperm injection (ICSI), remains largely unvalidated. Aims: To evaluate whether manual MFSS improves sperm quality and clinical outcomes compared with DGC in ICSI cycles. Methods: This prospective cohort study was conducted at My Duc Hospital, HCMC, Vietnam and included couples undergoing ICSI between February and November 2024. The primary outcome was the Day-3 embryo formation rate. Secondary outcomes included sperm motility, morphology, fertilisation, blastocyst development and clinical pregnancy outcomes. Between-group comparisons were performed using the [Formula: see text]-test, Mann–Whitney [Formula: see text] test or Fisher’s exact test, as appropriate. A [Formula: see text]-value [Formula: see text] was considered statistically significant. Results: Sixty couples were included, with 30 undergoing sperm preparation using MFSS or 30 using DGC. The Day-3 embryo formation rate did not differ significantly between the MFSS and DGC groups (83% vs 94%, [Formula: see text]). Compared with DGC, MFSS resulted in significantly higher progressive motility (91.8% vs 82.4%, [Formula: see text].001) and significantly lower proportions of immotile sperm (0.3% vs 8.5%, [Formula: see text] and sperm with head abnormalities (80.8% vs 88.5%, [Formula: see text]); sperm concentration was higher in the DGC group. Fertilisation, blastocyst development and clinical pregnancy outcomes were comparable between the two groups (all [Formula: see text]). Conclusions: Use of MFSS achieved similar embryological and clinical outcomes to use of DGC while improving sperm motility and morphology.