Two-year neurodevelopmental outcomes of preterm infants who received red blood cell transfusion

Background - Studies aimed at reducing neonatal anaemia or transfusing higher blood volumes did not find improvement in neurodevelopmental function at two years of age. This study investigated the relationship between the receipt, timing, and number of red blood cell (RBC) transfusions and neurodevelopmental outcomes among preterm infants. Materials and methods - This is a retrospective review of preterm infants (gestational age <34 weeks) with a full neurodevelopmental assessment at 18-36 months corrected age from October 2008 to September 2020. Bayley Scales of Infant and Toddler Development, third edition and the Modified Checklist for Autism in Toddlers were collected. Multivariable regressions were used to evaluate neurodevelopmental outcomes. Results - 654 preterm infants were evaluated with a mean follow-up of 25 months. 295 infants (45%) received a total of 1,322 blood transfusions. After adjustment for gestational age, baseline morbidity, and socioeconomic status, receipt of RBC transfusion was associated with decreased two-year cognitive and motor function, but not language (p=0.047, 0.025, and 0.879, respectively). There was no significant difference in outcomes between receipt of transfusion in the first week of life compared to after. Number of transfusions was associated with decreased cognitive, language, and motor function (all p<0.001), and increased likelihood to develop severe neurodevelopmental impairment (adjusted-odds ratio, 1.09; 95% confidence interval, 1.03-1.15; p=0.004). Discussion - Our study demonstrates an association between RBC transfusion and lower cognitive and motor outcomes at two-years after adjustment for prematurity and illness at birth. Increasing number of transfusions worsened neurodevelopmental outcomes.