Association of red blood cell transfusions with bronchopulmonary dysplasia in preterm infants: a retrospective cohort study.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is the most common pulmonary complication in preterm neonates. Emerging evidence links red blood cell (RBC) transfusions to increased BPD risk. METHODS: We conducted a retrospective cohort study of all infants of extremely low birth weight (ELBW) admitted to our NICU from January 2021 to December 2023. Infants enrolled within 7 days of birth were followed until 36 weeks' postmenstrual age (PMA) or until discharge or death-whichever came first. We extracted data on RBC transfusions, baseline characteristics and BPD diagnosis from validated electronic health records. To minimise confounding, we applied propensity score matching (PSM), overlap weighting (OW), multivariable logistic regression (adjusted for prespecified covariates), and restricted cubic spline (RCS) regression to assess nonlinear dose-response relationships. RESULTS: Among 746 very low birth weight (VLBW) infants, BPD incidence was 35.2% (263/746). Before PSM, BPD occurred in 48.3% (224/464) of transfused infants vs 13.8% (39/282) of non-transfused infants (unadjusted OR=5.81; 95% CI: 3.96 to 8.53; p<0.001). After PSM (173 matched pairs), BPD remained significantly higher in the transfused group (39.3% vs 19.6%; adjusted OR=2.97; 95% CI: 1.76 to 5.04; p<0.001). OW yielded consistent results (OR=2.53; 95% CI: 1.64 to 3.91; p<0.001). In transfused infants (n=464), RCS regression showed a nonlinear association between timing of first transfusion and BPD risk (p=0.03). Neither total transfusion count nor blood storage duration correlated with BPD. CONCLUSIONS: RBC transfusions are linked to a greater risk of BPD in preterm infants, with the timing of the initial transfusion having a nonlinear effect on the development of BPD. These findings highlight the need for further investigation into optimal transfusion strategies to mitigate BPD risk in this vulnerable population.