Oxidative Stress and Varicocele-Associated Male Infertility.

Despite being regarded as one of the most common causes of male subfertility, the pathophysiology of varicocele remains largely unknown. Recently, oxidative stress (OS) is proposed to be the mediator in how varicocele may negatively impact fertility. The imbalance of reactive oxygen species (ROS) and seminal antioxidants results in damage to sperm DNA and lipid membrane. There is evidence demonstrating higher OS level in men with varicocele which is also positively correlated with clinical grading of varicocele. Moreover, a number of studies have revealed the negative correlation between OS and conventional semen parameters. Furthermore, various interventions have shown their potential in alleviating OS in men with varicocele-associated infertility. Although direct evidence on improving pregnancy rate is not available at the moment, varicocelectomy has demonstrated promising results in relieving OS. Oral antioxidants represent another option with a favourable safety profile. The supplement can be used alone or as adjunct to varicocelectomy. However, most of the studies are hampered by heterogenous dose regime and high-level evidence is lacking.