Mucosal ischemia leading to gut injury is accepted as the most plausible cause for this event. This can result from many stressful situations experienced by premature infants.
Hypoxia is known to be one of the commonest physiological stress to which the neonates are exposed.
It has been associated with NEC in clinical and experimental situations. Hypoxia results in decreased intestinal perfusion, which may lead to bowel necrosis. If the period of ischemia of Hypoxia is not long enough to injure the tissue irreversibly, most of it can be salvaged by reperfusing the tissue and therefore reintroducing oxygen and other nutrients. Reintroduction of O 2 to an ischemic or hypoxic tissue could cause an additional damage to the tissue which is mediated by free oxygen radicals. An endogenous antioxidant mechanism already exists to counteract the effect of free radicals in the tissues.