Oxidants and antioxidants in human fertility

Oxidants are highly unstable molecules that attack every chemical substance they come into contact. Oxidants modify the macromolecules both structurally and functionally. Body has defense mechanisms against oxidants in the form of both enzymatic and non-enzymatic antioxidants. Reactive oxygen species (ROS) are a group of oxidants formed during oxygen metabolism. ROS appears to be involved in the pathogenesis of many human diseases. In reproductive medicine, ROS have both physiological and pathological role in male and female reproduction. Oxidative stress develops when the generation of ROS overwhelms the scavenging capacity of antioxidants. Oxidative stress causes damage to spermatozoa, oocyte and embryos. It appears to play a role in both natural and in vitro fertilization and pregnancy. The patients with oxidative stress may benefit from the strategies to reduce oxidative stress and treatment with antioxidants.