P-030 Sperm samples with elevated double-strand DNA fragmentation demonstrate similar fertilization outcomes to low fragmentation when treated: a retrospective analysis of egg donor cycles with PGT-A

Study question Does the presence of high double-strand DNA fragmentation (≥60%) in sperm samples significantly compromise fertilization, blast formation, and overall euploidy rates in egg donation cycles? Summary answer In a retrospective analysis of 303 donor-oocyte cycles, increased sperm DNA double-strand fragmentation (≥60%) did not notably reduce fertilization, blastocyst formation, or euploid rate. What is known already Elevated DNA fragmentation in sperm has long been suggested to impair embryo quality and reduce reproductive outcomes. Double-strand (DS) DNA breaks, in particular, is believed to have a more deleterious effects than single-strand breaks on fertilization, blastocyst formation, and embryo ploidy. Prior studies suggest that higher DS fragmentation may increase aneuploidy rates or reduce implantation success. However, the clinical impact of moderate or even very high DS fragmentation remains debated. In many assisted reproduction laboratories, sperm selection techniques are implemented when DS fragmentation surpasses certain thresholds, yet robust prospective data remain scarce. Study design, size, duration This retrospective study examined 303 donor-oocyte cycles performed at a single fertility center between January/2022-December/2024. Sperm samples underwent DS fragmentation testing with the Comet assay and were classified into three groups: <60%, 60–69%, and ≥70%. Fertilization, blastocyst formation, and chromosomal status (assessed via PGT-a). The study aimed to determine whether high DS fragmentation had a negative impact on these outcomes compared with normal or moderately elevated fragmentation over the three-year retrospective period. Participants/materials, setting, methods Sperm-samples were prepared by swim-up or microfluidic-chip (CHIP-Fertile) if fragmentation ranged from 60–79%, and by SpermSlow selection if ≥ 80% or frozen semen sample. All oocytes originated from donors aged 18–35 years. Intracytoplasmic sperm injection (ICSI) was used for fertilization. Blastocysts were biopsied on Day 5-6 and analyzed via next-generation sequencing. Primary outcomes included fertilization yield (2PN/oocytes injected), blastocyst yield, and chromosome status (euploid/aneuploid/mosaic). Statistical comparisons were performed via ANOVA and linear models. Main results and the role of chance Among 303 cycles, 116 (62%) showed DS fragmentation <60%, 104 (23%) had 60–69%, and 83 (15%) had ≥70%. No significant differences were observed in total M2 oocytes or PN2 embryos across groups: mean (±SD) values were 7.23 ± 2.22, 7.19 ± 2.20, and 7.53 ± 2.34, respectively (p = 0.54). Total blastocyst numbers also remained comparable (5.75 ± 2.02, 5.57 ± 2.20, 5.88 ± 2.15; p = 0.59). Euploid outcomes showed no statistically significant variation: 3.03 ± 1,64 in < 60%, 2.85 ± 1.62 in 60–69%, and 3.28 ± 1.54 in ≥ 70% (p = 0.19). Linear regression modeling of euploid embryo proportions revealed no meaningful association with DS fragmentation group or male age (p = 0.120). Aneuploid rates similarly did not differ, and mosaic rates remained constant among groups. The overall model R-squared was consistently low (<2%), indicating neither fragmentation level nor age accounted for substantial variation in these embryologic endpoints. These findings suggest that sperm samples with elevated DS fragmentation have similar fertilization outcomes or chromosomal status within egg-donation cycles when treated with additional sperm-selection techniques. Limitations, reasons for caution As a retrospective analysis from a single center, the possibility of confounding by unmeasured variables cannot be ruled out. This study focused on egg donation cycles, which may not fully generalize to own-egg IVF. Although selection techniques were standardized, randomized trials and larger cohorts are needed to confirm these findings. Wider implications of the findings Our findings suggest that sperm samples with increased double-strand DNA fragmentation justify the use of adequate sperm-selection techniques such as SpermSlow or microfluidic-chip in egg donation cycles. However, a comprehensive assessment of additional male and female factors remains crucial. Trial registration number No