P-046 Sperm mitochondrial DNA copy number and mitochondrial function in normozoospermic men may predict fertilization rates after intracytoplasmic sperm injection

Abstract Study question Do sperm mitochondrial DNA copy number (mtDNAcn) and function correlate with fertilization rates after intracytoplasmic injection (ICSI)? Summary answer We reveal a negative correlation between mtDNAcn ICSI, while higher corresponded to an increase in capacity. What is known already Over 40% of male-factor infertility unknown origin (unexplained idiopathic nature). As current diagnoses remain largely descriptive, the identification markers predicting capacity will hold key towards improved treatment. Mitochondria are fundamental for supporting spermatogenesis fertilization. A recent study showed that altered levels proteins led oocyte-activation deficiency, resulting failure ICSI. Poor semen parameters have also been linked high mtDNAcn, however relationship remains unexplored. Further characterization may uncover prognostic associated sperm-related failure. design, size, duration Twenty normozoospermic samples were included study. These obtained from oocyte donation ICSI cycles, performed March 2021 November 2022. Both fresh cryopreserved analysed. Five million collected ejaculate genomic (gDNA) isolation quantification, remainder sample was used functional analysis. analyses on washed samples, swim-up. Participants/materials, setting, methods Mean paternal age BMI 40 ± 5.8 years 25 2.3 kg/m2, respectively. evaluated using qPCR, by assessing ratio mitochondrial-to-nuclear genes (NT-ND4/B2M). For our studies, we quantified membrane potential (MMP) individual spermatozoa JC-1 staining flow cytometry. Flow cytometry analysis ≥ 10 treated uncoupler 15 minutes (1 µM trifluoromethoxy-carbonylcyanide-phenylhydrazone, FCCP) controls. Spearman applied. Main results role chance observed variable cohort (69.0 24.9%). One resulted total (TFF) analyzed independently. In (5.8 AU 2.61) correlated negatively progressive motility (rs = -0.65) rate -0.32). Notably, TFF presented highest value (13.9 2.77). revealed two distinct populations, corresponding motile immotile sperm. While low or undetectable aggregates (red signal), different MMP (ratio INTred/INTgreen) (2.3 1.83). sperm, positive 0.59). raw semen, association -0.53). Limitations, reasons caution Cryopreservation affect active mitochondria its effect intensity be established. Our limited size warrants careful interpretation. Wider implications findings suggest increasing MMP. Sperm male fertility outcomes. validation deliver clinically useful markers, aiding diagnosis, treatment counselling. Trial registration NA