NEC is a syndrome of acute intestinal necrosis. The etiology is unknown and pathogenesis is complex and multi factorial. It is the most common serious surgical disorder among infants in NICU & a significant cause of neonatal morbidity and mortality. It is seen in 2.5% of all NICU admissions and has an overall mortality rate of 30-40% with mortality increasing to more than 80% in neonates less than 1kg.

There are various predisposing factors:

• Prematurity: Seen commonly at a mean gestational age of 30-32 wks. (AGA). It is the single greatest risk factor. Incidence of NEC increases as gestational age decreases.
• In Term infants & near terms : Conditions predisposing to decreased gastrointestinal oxygen delivery
• Perinatal asphyxia (lower 1 minute apgar score)
• Lower cord PH (acidosis)
• Polycythemia
• RDS / apnea
• Shock
• Umbilical artery catheterization
• Early / or large volume nasogastric feeding
• Congenital heart disease