Table 1.

Risk factors for NEC in CHD

Risk factors	Comment
Prematurity	Risk increases with decreasing gestation [10]
Low birth weight	Increased risk reported in some but not all studies [6, 12]
	Associated with poorer outcomes and mortality[12]
Low cardiac output	Episodes of low cardiac output/shock associated with OR 6.5 for NEC[2]
Specific diagnoses	Hypoplastic left heart syndrome (incidence 6.1–9%) [5, 11, 12]
	Duct-dependent lesions – incidence 5% [5]
	Truncus arteriosus and aortopulmonary window [2]
	Atrioventricular septal defect in VLBW population [1]
Prostaglandin (PGE2)	Longer duration of prostaglandin may be associated with increased risk [6]
	Higher doses may be associated with increased risk [2]
RACHS-1 Score	Higher score associated with increased risk [5]
Associated syndromes	Trisomy 21: association demonstrated in VLBW infants [1]
Red Blood Cell Transfusion	Higher rates noted in infants who developed NEC. Causality not established[32]