Oxidative Stress and Reproduction Health: Physiology, Pathology, and Clinical Biomarkers

Abstract

Reactive oxygen species (ROS) are free radicals derived from oxygen during normal cellular metabolism. Cells, under aerobic conditions, have a defense system against ROS, and in normal circumstances, there is an appropriate balance between prooxidants and antioxidants. When an overproduction of ROS develops or the body fails to eliminate ROS in excess, oxidative stress arises, during which ROS accumulate and damage cells and tissues. ROS plays a crucial role in the physiological processes and signaling pathways associated in both male and female fertility. In females, oxidative stress acts as a mediator in the modulation of important ovarian functions, and its complications such as abortions, recurrent pregnancy losses, preeclampsia, and gestational diabetes. In males, ROS plays an important role in normal physiological processes such as capacitation, hyperactivation, acrosome reaction, and sperm-oocyte fusion to ensure appropriate fertilization. However, high concentrations of ROS cause sperm pathologies (ATP depletion) in the form of inadequate axonemal phosphorylation or lipid peroxidation, resulting in a loss of sperm motility and viability. This chapter will highlight the mechanisms, production, physiological, and pathophysiological roles of ROS in relation to the male and female reproductive system, and recent advances in diagnostic methods that use ROS as biochemical markers.