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Clinical features and diagnosis of necrotizing enterocolitis in newborns

Richard J Schanler, MD
Section Editor
Steven A Abrams, MD
Deputy Editor
Melanie S Kim, MD


Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal emergencies in the newborn infant. It is a disorder characterized by ischemic necrosis of the intestinal mucosa, which is associated with inflammation, invasion of enteric gas forming organisms, and dissection of gas into the muscularis and portal venous system [1]. Although early recognition and aggressive treatment of this disorder has improved clinical outcomes, NEC accounts for substantial long-term morbidity in survivors of neonatal intensive care, particularly in premature very low birth weight infants (birth weight below 1500 g).

The clinical features and diagnosis of NEC are reviewed here. The pathology, pathogenesis, management, and prevention of this disorder are discussed separately. (See "Pathology and pathogenesis of necrotizing enterocolitis in newborns" and "Management of necrotizing enterocolitis in newborns" and "Prevention of necrotizing enterocolitis in newborns".)


Necrotizing enterocolitis (NEC) occurs in 1 to 3 per 1000 live births and 1 to 7.7 percent of admissions to neonatal intensive care units (NICUs) [2].

Preterm infants — The incidence decreases with increasing gestational age (GA) and birth weight (BW), and is about 6 to 7 percent in very low birth weight (VLBW) infants (BW less than 1500 g) [3-5].

This was illustrated in one study of VLBW infants born between 1999 and 2001 from the National Institute of Child Health and Human Development (NICHD) neonatal network cohort [3]. The overall rate of NEC was about 7 percent. Rates were inversely related to BW as follows:

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Literature review current through: Nov 2017. | This topic last updated: Feb 18, 2016.
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