The Oxidative Stress in the Fetus and in the Newborn

Abstract

Free radical (FR) generation is an unavoidable consequence of life in an oxygen-rich atmosphere. FRs can be considered a double-edged sword. Their beneficial effects occur at moderate concentrations and include their physiological roles in cellular responses to noxia, as in defense against infectious agents, in the function of a number of cellular signaling pathways, and in the induction of a mitogenic response. The overproduction of FRs and the insufficiency of antioxidant mechanisms result in oxidative stress (OS), a deleterious process and important mediator of damage to cell structures and tissues. OS can occur before birth as a consequence of hypoxic–ischemic or inflammatory processes and also at birth in all newborns because of the hyperoxic challenge during the transition from the hypoxic intrauterine environment to extrauterine life. During the perinatal period, OS can be magnified by other predisposing conditions such as hyperoxia, hypoxia, ischemia, hypoxia–reperfusion, inflammation, and high levels of non-protein-bound iron (NPBI).