Accidental Administration of Anti-D Immunoglobulin to an Rh(D)-Positive Neonate: A Case Report.

Anti-D immunoglobulin (RhIg) is administered to Rh(D)-negative mothers to prevent alloimmunization in Rh(D)-incompatible pregnancies, and is contraindicated in Rh(D)-positive individuals. Herein, we report a case of accidental intramuscular administration of RhIg to an Rh(D)-positive neonate. A female infant was born at 39 weeks of gestation with a birth weight of 2,432 g. Shortly after birth, one vial of RhIg (250 μg), which should have been administered to the mother, was mistakenly injected into the neonate. The infant was transferred to our neonatal intensive care unit at one day of age for careful observation. On admission, the infant was in good general condition without pallor or jaundice. Laboratory tests revealed a hemoglobin level of 16.9 g/dL and a total bilirubin level of 4.54 mg/dL. The direct Coombs test was positive (2+). During hospitalization and subsequent outpatient follow-up, hemoglobin and bilirubin levels remained within the reference ranges, and neither phototherapy nor transfusion was required. The direct Coombs test remained positive for approximately three months, after which it spontaneously became negative. Although theoretical concerns exist regarding hemolysis after RhIg administration in Rh(D)-positive neonates, severe hemolytic complications were not observed in this case. Based on our case and previous reports, careful short-term observation followed by outpatient follow-up appears to be a reasonable management strategy for similar accidental administrations.