Recent research into cell-free DNA (cfDNA) in semen has increased our understanding of its potential roles in male reproductive science, infertility diagnostics, and even non-invasive diagnostics (such as non-invasive preimplantation genetic testing), marking a shift from merely observing cfDNA as a by-product of cellular turnover to investigating its clinical utility. Seminal plasma contains significant amounts of cfDNA, and several studies published over the past few years have begun to characterize its origin, structure, associations with sperm quality, and diagnostic purposes (Huang et al., 2025).
A key development in this field has been the detailed molecular profiling of cfDNA in seminal plasma. Huang and team (2025) have shown that cfDNA in seminal fluid is not a uniform mixture but consists of distinct fraction sizes, including nucleosomal (short) and high molecular weight (HMW) fragments. Analyses into the tissue of origin using genetic markers (methylation signatures) revealed that, alongside sperm-derived DNA, seminal cfDNA includes contributions from somatic cells such as prostate cells and immune cells, with prostate-derived cfDNA sometimes constituting over 20% of the HMW fraction in non-vasectomized men (Huang et al., 2025). These findings suggest that seminal cfDNA has the potential to reflect on health conditions beyond fertility, i.e. male reproductive tract cancers. Thus, this tissue complexity is essential as it suggests that seminal cfDNA could reflect both, reproductive tract health and systemic biological processes. As opposed to cfDNA in blood, which contains contributions from many tissues and is diluted by circulation, seminal cfDNA appears to retain localized signals from the male reproductive system, making it potentially more sensitive for detecting genital tract pathologies (Huang et al., 2025).
Recent studies have documented associations between cfDNA levels and traditional semen parameters. For example, men with abnormal sperm characteristics, such as oligozoospermia (low sperm count), teratozoospermia (abnormal morphology), and azoospermia (no detectable sperm), were found to exhibit increased seminal cfDNA levels compared to normozoospermic controls (Di Pizio et al., 2021). Higher cfDNA levels were particularly notable in azoospermic cases, suggesting a link between cfDNA release and underlying spermatogenic dysfunction.
Similarly, research into cell-free mitochondrial DNA (cf-mtDNA) in seminal plasma demonstrates that mitochondrial cfDNA copy number correlates with core semen quality parameters, including sperm concentration, motility, and morphology (Chen et al., 2018). A decrease in cf-mtDNA levels was associated with common semen abnormalities such as reduced motility and oligoasthenozoospermia (combined low count and motility), and these changes were negatively correlated with oxidative stress markers. This suggests that cf-mtDNA could serve as a novel biomarker of semen quality, potentially reflecting mitochondrial integrity and oxidative damage within the male reproductive tract.
Further refining cfDNA’s diagnostic use, recent studies of cfDNA fragment size patterns and end motifs, has provided an early ‘atlas’ of seminal cfDNA in healthy individuals versus men with infertility conditions such as varicocele or non-obstructive azoospermia (Lazovska et al., 2025; Wu et al., 2025). This work revealed distinct cfDNA size distributions and methylation features associated with specific disorders, achieving promising differentiation between disease states in pilot studies. Such cell signatures could enhance non-invasive subtyping of male infertility and inform tailored clinical management (Wu et al., 2025).
Further studies are investigating cfDNA’s potential to guide clinical decisions: an early study suggests that cfDNA testing in semen from men with non-obstructive azoospermia may predict the success of sperm retrieval procedures, identifying genetic mutations associated with absent spermatogenesis and offering a non-surgical alternative to biopsy in some cases (Cheung et al., 2024).
In summary, growing research on seminal cfDNA is unveiling its complex roles as both a mirror of sperm health and a source of tissue-specific signals from the male reproductive system. These findings support its promise not only as a biomarker for male infertility but also as a platform for non-invasive diagnostics of reproductive tract disorders, potentially transforming how clinicians assess and monitor male reproductive health.
Chen, Y., Liao, T., Zhu, L., Lin, X., Wu, R., & Jin, L. (2018). Seminal plasma cell-free mitochondrial DNA copy number is associated with human semen quality. European journal of obstetrics, gynecology, and reproductive biology, 231, 164–168. DOI:10.1016/j.ejogrb.2018.10.048
Cheung, S., Rosenwaks, Z., Palermo, G.D., (2024). A cell-free DNA test in semen of nonobstructive azoospermic men to predict spermatogenesis, Human Reproduction, Volume 39, P-570, Issue Supplement_1, July 2024, DOI:10.1093/humrep/deae108.905
Di Pizio, P., Celton, N., Menoud, P. A., Belloc, S., Cohen Bacrie, M., Belhadri-Mansouri, N., Rives, N., Cabry, R., & Benkhalifa, M. (2021). Seminal cell-free DNA and sperm characteristic's: An added biomarker for male infertility investigation. Andrologia, 53(1), e13822. DOI:10.1111/and.13822
Huang, S., Hart, J. C., Smith, J. F., Bench, S., Yepes, L. R., Griscom, B., & Clark-Langone, K. M. (2025). Tissue of origin characterization of cell free DNA in seminal plasma: Implications for new liquid biopsies. PloS one, 20(3), e0317712. DOI:10.1371/journal.pone.0317712
M Lazovska, L Bardina, D Gudra, L Gailite, V Fodina, J Jerenpreiss, P-018 Seminal Plasma Cell-Free DNA as a Non-Invasive Marker for Spermatogenesis and Male Infertility: Insights from Tissue-of-Origin Analysis, Human Reproduction, Volume 40, Issue Supplement_1, June 2025, deaf097.327, DOI:10.1093/humrep/deaf097.327
Wu, X., Meng, F., Zhang, H., Li, Z., & Zhao, K. (2025). Seminal plasma cfDNA fragmentomics landscape delineates male infertility subtypes. Clinical epigenetics, 17(1), 163. DOI:10.1186/s13148-025-01973-2
