Hemolytic disease of the newborn (HDN) occurs when a mother's immune system produces antibodies that attack the red blood cells of her baby. This often happens when the mother has a different blood type than the baby, particularly in cases involving the Rh factor. The condition can lead to anemia, jaundice, and other serious health issues for the newborn. Treatment for HDN may include blood transfusions or phototherapy to reduce bilirubin levels. Early detection through prenatal care is essential, as it can help manage the risks associated with this condition and improve outcomes for affected infants.