Sperm DNA Fragmentation in Male Infertility

Abstract

Infertility, defined as the inability to conceive after 12 months of regular unprotected intercourse, affects approximately 15% of couples in Algeria, representing a growing public health concern. Male factors are responsible in more than half of these cases; however, national research on male infertility remains extremely limited. This study addresses this gap by highlighting the importance of sperm DNA fragmentation testing as a key tool in the evaluation of male fertility and by proposing a cost-effective, locally applicable protocol. Several techniques have been developed to assess sperm DNA fragmentation, including the Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, the Sperm Chromatin Structure Assay (SCSA), the Single Cell Gel Electrophoresis (COMET) assay, and the Sperm Chromatin Dispersion (SCD) test. Each offers varying sensitivity and methodological approaches to detect DNA damage in sperm cells. The study was conducted between February and May 2025 at the IGUERLAB laboratory in Blida, Algeria, and included both a clinical and an experimental phase. In the clinical part, eleven semen samples were analyzed using the SCD method with the Halo Sperm kit to evaluate DNA fragmentation and identify contributing risk factors. These included smoking, unhealthy diet, varicocele, prolonged standing posture, exposure to cold or heat, oligo-astheno-teratozoospermia (OAT) with necrospermia, and inguinal hernias. The results showed that all investigated factors were associated with varying levels of DNA fragmentation. For example, smokers had DFI values of 85%, 5%, and 33%; those with an unhealthy diet showed values of 25%, 85%, 40%, 93%, and 33%; and patients with varicocele presented DFI values ranging from 5% to 93%. Cold and heat exposure were also associated with elevated DFI, as were OAT and inguinal hernias, with DFI values of 25% and 72%, respectively. In the protocol development phase, four semen samples were used across six assay rounds to refine and test a local SCD-based method. During each assay, results were compared to those of the commercial Halo Sperm kit. One assay successfully produced a clear halo, confirming the protocol’s reliability. This study thus provides both clinical insights and a practical diagnostic tool to support fertility assessment in Algeria