Neonatal Nurse Practitioner Practice Exam 2025 – Complete Prep Resource

The clinical manifestation that is consistent with ABO incompatibility is jaundice occurring in the first 24 hours of life. ABO incompatibility arises when an infant's blood type is A, B, or AB, and the mother is type O. The mother’s immune system may produce antibodies against the A or B antigens present in the infant's red blood cells, leading to hemolysis.

As a result of this hemolysis, free bilirubin is released into the circulation, leading to an increase in bilirubin levels and subsequently causing jaundice. The early onset of jaundice, particularly within the first day after birth, is a key indicator of ABO incompatibility. This early manifestation is distinct from other types of hemolytic disease, such as Rh incompatibility, which often leads to jaundice developing later due to more gradual hemolysis and is generally observed around the second or third day of life.

In contrast to the selected response, severe hepatosplenomegaly is less commonly associated with ABO incompatibility and would instead be more indicative of Rh incompatibility or other conditions causing significant anemia. Rapidly developing hemolysis can occur in both conditions but is more characteristic of Rh incompatibility, where the hemolysis is often more severe