RESUMO
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.
