RESUMO
Reactive Oxygen Species (ROS) are produced as a normal product of aerobic metabolism. Naturally, there is an array of protective mechanisms that neutralize ROS, while any potential imbalance between ROS and antioxidants results in oxidative stress. In an In Vitro Fertilization (IVF) setting, existing literature suggests a favorable outcome in terms of oocyte quality/maturation and fertilization rate with increased ROS levels, while other study groups have presented significant data on the detrimental effect of increased ROS concentration in the quality of embryos exposed and their potential to advance. In this study, we examine the conflicting views of the role of ROS in fertilization and embryo quality, especially through their concentration in the follicular fluid of subfertile women undergoing IVF. The current debate could possibly be attributed to the different assay methods and end-point outcomes employed by each research group, along with the noted limited number of the relevant studies published on the subject. Properly conducted studies can further validate and elicit the exact role of ROS as well as their association to female reproduction, and especially to women undergoing IVF.