P0760 - Should we screen cord blood for ABO incompatibility?

Background: Routine performance of blood group and direct coombs test (DCT) on cord blood is controversial. At our institution, from 2007-2013, cord blood type and DCT was obtained for every newborn born to O positive mothers. For newborns with ABO incompatibility, first bilirubin check occurred at 6 hours of life. Phototherapy would commence in newborn nursery if needed with transfer to neonatal intensive care unit (NICU) for intensive phototherapy or additional intervention, including IVIG and exchange transfusion. Beginning 2014, routine cord blood group and DCT was no longer performed. First bilirubin level was checked between 24-36 hours of life with initiation of phototherapy as indicated and transfer to NICU for higher level of care as needed.

Objective: To determine if there was a change in NICU admissions from newborn nursery for intensive phototherapy and additional management of hyperbilirubinemia when routine cord blood group and DCT was obtained compared to when not obtained at delivery.

Methods: This is a retrospective analysis of all neonates admitted to the NICU from the newborn nursery between 1/2007 and 2/2020 with hyperbilirubinemia. Clinical characteristics, including age at first bilirubin level, first and peak bilirubin level, need for intensive phototherapy, IVIG, and blood transfusion were compared between the cohort with blood group and DCT obtained at delivery and the cohort with no labs obtained at delivery.

Results: A total of 29,447 infants were born and 8,663 infants were admitted to NICU during the study period. Significantly more newborns, with and without ABO incompatibility, were admitted to the NICU from the newborn nursery for hyperbilirubinemia requiring intensive phototherapy when no labs were obtained at birth (Table 1). For newborns with ABO incompatibility, significantly more infants had peak bilirubin at exchange blood transfusion level and required IVIG when no labs were obtained at delivery. There was also a significant difference in time of and the level of the first bilirubin, with initial bilirubin levels collected later and initial bilirubin higher in the cohort who did not have labs at delivery (Table 2). No neonates in either group required exchange blood transfusion.

Conclusions: Not obtaining blood group and DCT at delivery has led to a significant increase in NICU admissions from the newborn nursery for hyperbilirubinemia and ABO incompatibility. If blood group and DCT was not performed at delivery, more neonates with ABO incompatibility were found to have higher bilirubin levels which approached exchange transfusion levels and required IVIG. Initiating policy to obtain blood group and DCT at birth for infants born to O positive mothers, a rather low-cost initiative, will prevent NICU admissions for higher level of care and potential long-term complications in newborns with ABO incompatibility.