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

In most cases of Rh hemolytic disease, jaundice appears within 24 hours after birth and rapidly worsens; in contrast, jaundice in most ABO hemolytic disease cases typically emerges on days 2–3. Serum bilirubin is predominantly unconjugated; however, in severe hemolysis complicated by cholestasis, conjugated bilirubin levels may also rise.

② Anemia

Anemia severity varies. In severe Rh hemolytic disease, profound anemia—or even heart failure—may be present at birth. Additionally, because maternal antibodies persist in some infants, late-onset anemia may develop between weeks 3 and 6 postnatally.

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 such as lethargy, poor feeding, fixed gaze, and seizures. Without prompt treatment, it may lead to death or cause long-term sequelae, including motor dysfunction and intellectual disability. Although clinical manifestations of ABO and Rh incompatibility are largely similar, 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.