Dr. Tadros is assistant professor and director of male infertility and sexual health at Southern Illinois University, Springfield, and Dr. Agarwal is professor and director of the Andrology Center at Cleveland Clinic’s American Center for Reproductive Medicine and on staff in the Glickman Urological and Kidney Institute, Cleveland. Section Editor Steven A. Kaplan, MD, is professor of urology at the Icahn School of Medicine at Mount Sinai and director of benign urologic diseases, Mount Sinai Health System, New York. Follow him on Twitter at @MaleHealthDoc.
Despite the ongoing controversies regarding the accuracy and predictive power of routine semen analysis, it continues to be used by many clinicians worldwide as the de facto test for male infertility (Int Braz J Urol 2014; 40:443-53). In its best practice statement for the evaluation of the infertile male, the AUA has proposed the use of advanced tests of sperm function in certain patients to enhance the diagnostic accuracy of semen analysis, specifically in cases of unexplained infertility, recurrent pregnancy loss, or failure of intrauterine insemination (IUI) and in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) (The Optimal Evaluation of the Infertile Male. AUA Best Practice Statement, 2010).
As explained in this article, these new tests have the potential to improve our ability to better diagnose and treat complicated male infertility patients.
Oxidative stress is thought to contribute to 40%-80% of male infertility (Fertil Steril 2003; 79:829-43) and arises as a consequence of excessive production of reactive oxygen species (ROS) and impaired antioxidant defense mechanisms (figure 1) (Curr Med Chem 2001; 8:851-62). Although small amounts of ROS are important for normal sperm function, an excess of these highly reactive molecules can cause damage to the lipid-rich plasma membranes and the integrity of DNA within the sperm nucleus, as well as impaired motility and spermatozoa apoptosis (Fertil Steril 2003; 79:829-43).
Antioxidants such as some vitamins and minerals combat these overproduced ROS. In addition to excess ROS, oxidative stress can be due to insufficient concentrations of antioxidants as well. Over the last decade, research has provided growing support for the fact that oxidative stress leads to abnormal semen parameters. In addition, more and more laboratory tests are now available to measure this oxidative stress. Therefore, it would be reasonable to potentially screen all infertile men for the presence of increased ROS levels. Specialized training and equipment, the lack of cost-effective and efficient assays, and, perhaps most importantly, the lack of a universally accepted analytical methods have prevented ROS testing from being included as part of the routine infertility workup.