Multiple red blood cell transfusions and iron overload in very low birthweight infants

Background and Objectives To estimate the risk of iron overload in very low birthweight ( VLBW ) infants who receive more than two red blood cell ( RBC ) transfusions, in comparison with those who receive two or less during their hospital stay. Materials and Methods Prospective open cohort study in VLBW infants with >2 (exposed) and ≤2 (non‐exposed) RBC transfusions. Ferritin, alanine aminotransferase ( ALT ) and aspartate aminotransferase ( AST ) were measured at birth and after each RBC transfusion. The incidence of iron overload was determined. Risk factors were analysed using a logistic regression model. RBC transfusion volume correlations with ferritin, ALT and AST were calculated with Spearman's rank correlation coefficient, as well as correlations between ferritin and aminotransferases. Results A total of 63 patients were enrolled, 18 of which were exposed and 45 non‐exposed. Twelve patients developed severe iron overload, eight exposed (44·5%) vs. four (8·8%) non‐exposed ( RR : 5, 95% CI : 1·7–14·6). Multivariate analysis showed that the number of transfusions increased the risk of iron overload ( OR : 2·07, 95% CI : 1·36–2·14) while a higher one‐minute Apgar score was associated with a lower risk ( OR : 0·56, 95% CI : 0·32–0·99). Severe iron overload mainly occurred with a transfusion volume higher than 120 ml/kg. There was a positive correlation between ferritin and transfusion ( r = 0·53; P < 0·001). Conclusion There was a higher risk of iron overload in exposed infants in comparison with non‐exposed infants. Severe iron overload in VLBW infants may occur with a total transfusion volume >120 ml/kg.