Maternal anti-D antibodies inducing delayed hemolytic disease in a newborn

Background Hemolytic disease of fetus and newborn (HDFN) is caused by maternal antibodies that react to fetal red blood cell antigens. HDFN is associated with perinatal mortality and long-term neurological deficits in severe cases. Alloantibodies will lead to hemolysis of fetal erythroid cells and cause fetal and neonatal anemia. Rhesus D (Rh D) antigen is a frequent cause of HDFN. In most cases, the maternal alloantibody transported across the placenta causes hemolysis in utero. Only a few cases of delayed-onset hemolysis in the newborn have been reported yet.Case report A mother with a high anti-D titer gave birth to a newborn with a normal postnatal hemoglobin level. The newborn's direct antiglobulin test (DAT) was positive for immunoglobulin G, with an anti-D titer of 4096 in elution. After 2 days of phototherapy for mild icterus, the newborn was discharged with a hemoglobin of 17.4 g/dl and without any complications. Twenty days after birth, the newborn was admitted to the children's hospital because of paleness. On admission, hemoglobin was 5.6 g/dl and total bilirubin was 2.6 mg/dl. No infection was found. DAT was positive with an anti-D titer of 4096 in elution. After red blood cell transfusion, hemoglobin increased and the newborn was discharged. On day 34 postpartum, hemoglobin was 8.1 mg/dl and anti-D titer was 1024 in elution. No further transfusion was indicated. The newborn was discharged in a good physical condition for regular follow-up by the resident pediatrician.Conclusion Implementation of Rh D antibody prophylaxis in Rh D-negative non-immunized women has led to a marked reduction in the incidence of Rh D alloimmunization and eventually HDFN. However, maternal Rh-D antibodies can induce delayed HDFN, even in the absence of hemolysis signs at birth. Increased vigilance and frequent monitoring of newborns with maternal alloantibodies are of great importance to prevent complications of a delayed HDFN.