Effect of sperm swim - up vs density gradient centrifugation on embryo aneuploidy detected by non-invasive chromosomal screening in conventional IVF.

Objective: The aim of this study was to compare the aneuploidy rates of blastocysts obtained via conventional in vitro fertilization (IVF) using sperm prepared by the swim-up (SU) and density gradient centrifugation (DGC) methods, as detected by non-invasive chromosomal screening (NICS). This comparison would provide more evidence for selecting the appropriate semen processing technique for patients undergoing conventional IVF with NICS.

Methods: A retrospective analysis was conducted on patients who underwent conventional IVF and NICS at our hospital from January 2022 to May 2024.Patients were grouped by semen - processing method (SU and DGC groups). Semen parameters before and after processing on oocyte - retrieval day, oocyte numbers (retrieved, MII), and 2PN embryos were compared. Fertilization, cleavage, D3 high - quality embryo, embryo ploidy, and aneuploidy rates between the two groups were analyzed.

Results: There were no statistically significant differences in multiple indicators such as the number of retrieved oocytes between the two groups (P > 0.05); the rate of high-quality embryos on Day 3 in the DGC group was significantly higher than that in the SU group (53.9 % vs. 48.20 %, P = 0.011).The proportion of embryos with Grade A in the DGC group was 31.8 % (262/824), while that in the SU group was 39.4 % (119/302), showing a statistical difference (P = 0.017). The euploidy rate in the DGC group was 21.7 % (179/824) and the aneuploidy rate was 71.2 % (587/824), while the euploidy rate in the SU group was 25.8 % (78/302) and the aneuploidy rate was 68.9 % (208/302). There was no significant difference between the two groups (P > 0.05).

Conclusion: The SU method yielded a higher proportion of Grade A embryos but did not reduce aneuploidy rates, suggesting its potential as a simpler, cost-effective alternative to DGC for NICS in conventional IVF.