P-056 Microfluidic Sperm Selection Enhances Euploidy Rates Compared to Swim-Up in ART

Abstract Study question Is the use of a microfluidic sperm selection (MSS) device associated with higher rates of euploid embryos when compared to swim-up? Summary answer The use of an MSS device resulted in a significantly higher euploidy rate than the conventional swim-up method, despite similar fertilization and cleavage rates. What is known already MSS is an advanced technique designed to select high-quality spermatozoa by mimicking the natural selection processes of the female reproductive tract. It aims to improve assisted reproductive technology (ART) outcomes by isolating sperm with superior motility and lower DNA fragmentation. Several studies have explored whether MSS leads to a higher proportion of euploid embryos compared to traditional selection methods like swim-up, but data remain limited. Study design, size, duration A retrospective case-control study including 41 patients who underwent two intracytoplasmic sperm injection (ICSI) cycles with preimplantation genetic testing (PGT) between 2023 and 2024. Participants/materials, setting, methods The study was conducted at a reproductive medicine center in Brazil. A total of 82 ICSI/PGT cycles were divided into two groups based on sperm selection method: G1 (MSS device) and G2 (swim-up). All patients first underwent ICSI using the swim-up technique, followed by a second cycle using the MSS device (Lenshooke®) for sperm preparation. Student’s t-test, Mann-Whitney U test, and chi-square test were applied, with p < 0.05 considered statistically significant. Main results and the role of chance There were no significant differences between the MSS and swim-up groups regarding female age (years) (40.02 ± 2.59 vs. 39.34 ± 2.48, p = 0.19), male age (years) (39.76 ± 4.50 vs. 39.10 ± 4.56, p = 0.43), sperm volume (mL) (2.86 ± 1.42 vs. 3.25 ± 1.45, p = 0.13), sperm concentration (million/mL) (50 × 106 [24–90] vs. 55 × 106 [27.5–100], p = 0.47), sperm motility (%) (50.90 ± 17.07 vs. 53.32 ± 18.59, p = 0.54), sperm midpiece morphology (%) (25.92 ± 9.87 vs. 30.94 ± 12.23, p = 0.06), and tail morphology (%) (28.28 ± 12.08 vs. 24.44 ± 12.90, p = 0.20). The number of retrieved mature oocytes (n) (8 [5–12] vs. 6 [4–10], p = 0.34), fertilization rate (n, 2PN stage) (6 [3–10] vs. 5 [3–8], p = 0.29), and cleavage rate (n, day 3 embryos) (5 [3–10] vs. 5 [3–7], p = 0.26) were also comparable between groups. However, the euploidy rate was significantly higher in the MSS group compared to swim-up (65.85% vs. 31.71%, p = 0.004). Limitations, reasons for caution As a retrospective study, this analysis is limited by sample size and potential selection bias. Larger prospective studies evaluating additional sperm quality parameters are necessary to confirm these findings and determine the broader clinical impact of MSS in ART. Wider implications of the findings MSS significantly increased euploidy rates, suggesting its potential as a superior sperm selection method in ART. Despite similar fertilization and cleavage rates, MSS may enhance embryo chromosomal integrity, improving outcomes. Incorporating MSS into ART protocols could optimize embryo selection, but larger prospective studies are needed to confirm its benefits. Trial registration number No