Objective To evaluate the association between blood transfusion in previous 2 days and necrotising enterocolitis (NEC) in infants admitted to neonatal intensive care units in Canada.

Patients and Methods Using the Canadian Neonatal Network database of admissions to neonatal intensive care units from 2003 to 2008, cases with NEC were matched with controls by gestational age (GA) at birth. Exposure to transfusion within 2 days of NEC (for cases) or 2 days before the median age of NEC diagnosis among cases of the same GA (for controls) was determined. After controlling for confounders, the differences in characteristics and neonatal outcomes of transfusion-associated NEC (TANEC) and NEC not associated with transfusion (non-TANEC) were compared.

Results NEC cases (n=927) were matched with 2781 controls. Transfusion in previous 2 days was significantly higher in NEC cases than in controls (15.5 vs 7.7%; adjusted OR (AOR) 2. 44; 95% CI 1.87 to 3.18). TANEC cases versus non-TANEC cases had a lower mean GA (25.8 vs 29.3 weeks), a lower mean birthweight (885 vs 1373 grams), and a higher proportion of infants with SNAPII score >20 (52.1 vs 22.9%). After adjustment for confounders, no significant differences in mortality (AOR 1.28, 95% CI 0.82 to 2.01), severe retinopathy (AOR 1.15, 95% CI 0.71 to 1.87), or severe neurological injury (AOR 0.83, 95% CI 0.43 to 1.60) were identified.

Conclusions Exposure to transfusion in previous 2 days was an independent risk factor for NEC. After controlling for confounders, no significant differences in mortality and morbidities were observed between infants who had transfusion-associated NEC and those with NEC not associated with transfusion.