Red Blood Cell Transfusions at 21 Days of Age or Older in Previously Transfusion-Naive Very Preterm Infants: Association with Neonatal Outcomes.

Objective: This study aims to assess the association of red blood cell (RBC) transfusion in a cohort of preterm infants with mortality, retinopathy of prematurity (ROP), and chronic lung disease (CLD) transfused at ≥21 days of life.

Methods: This retrospective cohort study included infants born at <30 weeks' gestation who survived ≥21 days, had not received any RBC transfusions before reaching 21 days of age, and were admitted to participating units in the Canadian neonatal network (2003-2009).

Results: Out of the 3,799 eligible infants, 3,309 infants did not receive RBC transfusion at  ≥21 days of age, whereas 490 received transfusion at  ≥21 days of age. Infants who did not receive RBC transfusion/s at  ≥21 days of age had higher birth weight (p<0.01) and higher gestational age at the time of birth (p<0.01) as compared with those who received transfusion/s at ≥21 days of age. Receipt of RBC transfusion/s at  ≥21 days of age was not associated with mortality (adjusted odds ratio [AOR] 1.20; 95% confidence interval [CI] 0.33-4.34) or severe ROP (AOR 1.02; 95% CI 0.59-1.77) but was associated with increased odds of CLD (AOR 1.78; 95% CI 1.43-2.22).

Conclusions: RBC transfusion/s at  ≥21 days of age in previously transfusion-naive preterm infants was associated with increased odds of CLD but not with ROP or mortality.