What happens to children with hemolytic disease?

Hemolytic disease refers to a condition in which the infant’s blood type is incompatible with that of the mother, leading to maternal blood-group antibodies crossing the placenta into the fetal circulation and destroying the infant’s red blood cells, thereby causing hemolysis. Hemolytic disease is generally classified into two types: ABO hemolytic disease and Rh hemolytic disease.

① Jaundice

Most infants with Rh hemolytic disease develop jaundice within 24 hours after birth, and it rapidly worsens. In contrast, jaundice in most cases of ABO hemolytic disease appears on days 2–3. Serum bilirubin is predominantly unconjugated; however, if hemolysis is severe enough to cause cholestasis, conjugated bilirubin levels may also rise.

② Anemia

The severity of anemia varies. In severe Rh hemolytic disease, profound anemia—or even heart failure—may be present immediately after birth. In some infants, persistent maternal antibodies can lead to late-onset anemia occurring 3–6 weeks postnatally.

③ Complications

Excessively high serum bilirubin levels may damage brain cells, resulting in kernicterus—the most severe complication of hemolytic disease. Kernicterus typically occurs 4–7 days after birth and manifests as worsening jaundice accompanied by neurological symptoms such as lethargy, poor feeding, fixed gaze, and seizures. Without prompt treatment, it may result in death or long-term sequelae including motor dysfunction and intellectual disability. Although ABO and Rh incompatibility both cause similar clinical manifestations of hemolysis, their severity and progression differ: ABO hemolytic disease tends to be milder and progresses more slowly, whereas Rh hemolytic disease is typically more severe and progresses more rapidly.