A Description of IVIG Use in Term Neonates With AB0 Incompatibility.

Objective To determine if treatment with IVIG of neonates with ABO incompatibility (without Rh incompatibility) results in decreased number of packed red blood cell (pRBC) transfusions and phototherapy use. Study Design An IRB-approved, single-institution retrospective study was conducted. Neonates ≥38 weeks gestational age born between 01/01/2007 and 12/31/2016 with ABO incompatibility were included. The comparison among groups was performed using Chi square and Fisher exact test for categorical variables; continuous variables were assessed by Kruskal-Wallis test. Results Six hundred and sixty-eight neonates with ABO incompatibility met inclusion criteria, 579 were included in the analyses. From those, 431 (74%) neonates had positive Direct Antiglobulin Test (DAT); 98 (17%) received IVIG and 352 (61%) received phototherapy. Thirty-six (6%) neonates received pRBC and 6 (1%) required exchange transfusions. Only 3 (0.5%) infants received pRBC transfusions post discharge, by 3 months of age. Neonates requiring IVIG had lower initial hemoglobin (13.6 g/dL vs 16.0 g/dL, p=<0.0001) and higher bilirubin at start of phototherapy (9.1 vs 8.1 mg/dL, p=0.0064). From the 42(7%) neonates who received simple and exchange transfusions, IVIG use was not associated with decreased use or number of transfusions (p=0.5148 and 0.3333, respectively). Newborns with A+ and B+ blood types had comparable initial hemoglobin, DAT positivity, APGARs, and bilirubin. However, infants with B+ blood group were more likely than A+ to require phototherapy (p<0.001), receive IVIG (p=0.003), and need phototherapy for a longer duration (p=0.001). Conclusion The results of this large retrospective study reveal that neonates with ABO incompatibility who received IVIG in the newborn period did not have reduced need for simple or exchange transfusions. Newborns with B+ blood type required more phototherapy and IVIG. Further studies are needed to better stratify neonates who would benefit from IVIG use in order to optimize treatment strategies and avoid unnecessary risks and adverse events.