The Role of Interventions to Reduce Oxidative Stress and Improve Sperm DNA Integrity Before ICSI

Abstract

In the era of assisted reproductive techniques where intracytoplasmic sperm injection (ICSI) may overcome the most severe form of male infertility, sperm with severe function defect may bypass the natural selection process and achieve clinical pregnancy and live birth. The risk of injecting DNA-damaged sperm into oocyte during ICSI is increasingly recognized with the understanding of oxidative stress (OS)-induced sperm DNA fragmentation (SDF) in the pathogenesis of male subfertility. Emerging evidence reveals the negative impact of poor sperm DNA integrity on ICSI outcomes, particularly miscarriage rate. The invention of various OS and SDF assays, on one hand, allows the investigation of potential treatment strategies in the alleviation of OS and SDF. On the other hand, presence of effective treatment is essential in further substantiating the role of laboratory assays in clinical practice. Several interventions including the use of sperm with short ejaculatory abstinence, oral antioxidant therapy, varicocele repair, advanced sperm selection techniques, and the use of testicular sperm have been explored. Most of these strategies have proven their efficacy in reducing OS and SDF significantly. However, clinical application of the techniques remains less clear due to limited clinical trials in the literature. Although improved ICSI outcomes have been observed in a number of retrospective and prospective studies, the treatment strategies should be utilized with caution in view of the lack of randomized study at the moment.