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. As a result, maternal blood-group antibodies cross the placenta into the fetal circulation, leading to destruction of the infant’s red blood cells and subsequent 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, in severe hemolysis complicated by 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 may cause late-onset anemia at 3–6 weeks of age.

③ Complications

Excessively elevated serum bilirubin levels can 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, including lethargy, poor feeding, fixed gaze, and seizures. Without prompt treatment, it may lead to death or long-term sequelae such as motor dysfunction and intellectual disability. Although ABO and Rh incompatibility produce similar clinical manifestations of hemolysis, their severity differs: ABO hemolytic disease tends to be milder and progresses more slowly, whereas Rh hemolytic disease is typically more severe and progresses rapidly.