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The role of the DNA fragmentation index in the diagnostic evaluation of fertile semen (Bachelor thesis)

Καναβάκη, Σωτηρία/ Kanavaki, Sotiria

The assessment of male fertility has traditionally relied on the conventional parameters of semen analysis; however, modern Andrology has increasingly shifted its focus toward the molecular integrity of the paternal genome. The present undergraduate thesis constitutes a retrospective observational study aiming to investigate the role of the fertile sperm DNA fragmentation index (fsDFI) and its association with the physicochemical characteristics of semen in the context of infectious and inflammatory disorders of the male reproductive system. For this purpose, clinical data were collected from individuals who underwent semen analysis at the SPERMLAB laboratory from 2010 to the present. The population of spermatozoa exhibiting progressive motility and normal morphology was isolated using Density Gradient Centrifugation (DGC), while the fsDFI was determined using the Sperm Chromatin Dispersion (SCD) test. The results of the statistical analysis showed that pathological conditions, such as prostatitis and epididymitis, significantly impair the secretory function of the accessory sex glands, leading to alterations in semen volume, pH, and liquefaction time. Furthermore, the multivariate logistic regression model demonstrated that alterations in these macroscopic parameters constitute independent predictors of the presence of microbial infection. The findings suggest that routine assessment of the DNA fragmentation index (DFI) is not required in all cases encountered in everyday clinical practice, as conventional physicochemical semen evaluation may provide sufficient information to guide the initial diagnostic work-up and therapeutic management. However, when assessment of sperm DNA fragmentation is considered clinically indicated, evaluation of the fsDFI—that is, the DNA fragmentation index measured exclusively in the subpopulation of fertile spermatozoa – appears to represent the most appropriate laboratory approach. Overall, the present study underscores that the clinical value of sperm DNA fragmentation assessment is maximized when interpreted in conjunction with the physicochemical parameters of semen, thereby providing a more comprehensive and accurate evaluation of sperm fertilizing potential.