Positive direct antiglobulin test: is it a risk factor for significant hyperbilirubinemia in neonates with ABO incompatibility?

Abstract

Objective: ABO blood group (ABO) incompatibility is a common cause of neonatal indirect hyperbilirubinemia. The direct antiglobulin test (DAT) can identify infants developing hemolytic disease. This study aims to evaluate the significance of DAT positivity among neonates with ABO incompatibility. Study Design: This retrospective study included 820 neonates with blood group A or B who were born to blood group O mothers. The study group consisted of neonates (n = 79) who had positive DAT, and the control group consisted of infants (n = 741) who had negative DAT. Demographic and clinical data of the neonates regarding jaundice were collected and compared statistically. Results:The bilirubin level at 24 hours of life (study group: 8 ± 2.6 mg/dL, control group: 6 ± 2.2 mg/dL, p < 0.001) and the highest bilirubin level (study group: 12.7 ± 3.6 mg/dL, control group: 10.4 ± 4.2 mg/dL, p < 0.001) were higher in infants with positive DAT. A total of 37 (46.8%) infants in the study group and 83 (11.2%) infants in the control group received phototherapy (PT) in the nursery (p < 0.001). In neonates with positive DAT, direct bilirubin level, duration of hospitalization, and PT in the nursery were higher (p = 0.002, <0.001, and <0.001, respectively), whereas hemoglobin level was lower (p < 0.001). Conclusion: In neonates with ABO incompatibility, a positive DAT is a risk factor for developing significant hyperbilirubinemia. Close follow-up of newborn infants with ABO incompatibility is crucial for early detection and treatment of neonatal jaundice to avoid early and late complications. Key Points The clinical spectrum of ABO incompatibility varies widely. The ABO incompatibility with positive DAT are at greater risk for high bilirubin levels. Infants with blood group incompatibilities must be monitored closely. © 2022 Georg Thieme Verlag. All rights reserved.