RBC transfusion and necrotizing enterocolitis in very preterm infants: a multicenter observational study.

The causal relationship between Packed red blood cell (RBC) transfusion and necrotizing enterocolitis (NEC) remains uncertain. This study aims to provide an exploration of transfusion and NEC in very preterm infants. Using data from the Chinese Neonatal Network cohort study between 2019 and 2021, the analysis focused on very preterm infants (with a birth weight of < 1500 g or a gestational age of < 32 weeks) who developed NEC after receiving transfusions. The time interval between the prior transfusion and NEC was analyzed. An uneven distribution of the time interval implies an association of transfusion and NEC. Additionally, multivariable logistic analysis was conducted to detect the prognosis of defined transfusion-associated NEC(TANEC). Of the 16,494 infants received RBC transfusions, NEC was noted in 1281 (7.7%) cases, including 409 occurred after transfusion. Notably, 36.4% (149/409) of post-transfusion NEC occurred within 2 days after transfusion. The time interval distribution showed a non-normal pattern (Shapiro-Wilk test, W = 0.513, P < 0.001), indicating a possible link between transfusion and NEC. TANEC was defined as NEC occurred within 2 days after transfusion. Infants with TANEC had a higher incidence of death (adjusted OR 1.69; 95% CI 1.08 to 2.64), severe bronchopulmonary dysplasia (adjusted OR 2.03; 95% CI 1.41 to 2.91) and late-onset sepsis (adjusted OR 2.06; 95% CI 1.37 to 3.09) compared with infants without NEC after transfusion. Unevenly high number of NEC cases after RBC transfusions implies transfusion is associated with NEC. TANEC is associated with a poor prognosis. Further research is warranted to enhance our understanding of TANEC.