Sperm DNA damage in men with severe asthenozoospermia

Background. Sperm motility is a fundamental factor for sperm penetration into the oocyte and fertilization. According to the World Health Organization (WHO) 2021, less than 42% of motility is called asthenozoospermia, which is one of the most common causes of male infertility. This retrospective cohort study aims to investigate sperm DNA damage with TUNEL and SCSA methods and its relationship with sperm parameters, age, and body mass index (BMI) in severe asthenospermia (<2% sperm motility) and normozoospermia. Methods. The study parameters between 111 subjects with severe asthenozoospermia and 113 subjects with normozoospermia were investigated. The 2010 World Health Organization guidelines were used to evaluate sperm parameters, and TUNEL and SCSA methods were used to assess sperm DNA damage. The statistical analysis was done using the t-test of two independent samples. Pearson's correlation coefficient was used to investigate the relationship between sperm DNA damage and sperm parameters, age, and BMI P<0.05 was considered significant. Results. The mean seminal volume, sperm concentration and count, and the percentage of sperm total motility and progressive motility were significantly lower in severe asthenospermic subjects compared to normozoospermic subjects (P<0.001). In addition, the mean percentage of sperm DNA damage in severe asthenozoospermic individuals was significantly higher than in normozoospermic individuals (P<0.001). There was also a positive and significant relationship between sperm DNA damage and the age of severely asthenozoospermic men. Conclusion. Sperm motility, sperm DNA damage, and the father's age are essential in the successful conception, development, and health of the embryo. Therefore, the evaluation of sperm DNA damage is recommended in examining male fertility and selecting the appropriate treatment approach for men with severe asthenozoospermia. Practical Implications. Considering that the sperm genome constitutes 50% of the genetic material of the next generation, evaluating sperm DNA health to determine the appropriate treatment approach in infertile men can be influential in the success of assisted reproductive techniques and in maintaining the next generation’s health.