A woman's first pregnancy is normal but her second pregnancy results in hemolytic disease of the newborn (HDN).The second child needed a transfusion to completely replace the agglutinating blood.The mother is most likely type __________ and both children are most likely __________.

Question

Quizplus · Accepted Answer

EThe mother is most likely AB, Rh-positive, and both children are most likely O, Rh-positive. Hemolytic disease of the newborn (HDN) occurs when there is an incompatibility between the blood types of the mother and fetus, most commonly involving the Rh factor. If the mother is Rh-negative and the fetus is Rh-positive, the mother can produce antibodies against the Rh-positive blood. However, in this scenario, since the first pregnancy was normal and the issue arose during the second pregnancy, it suggests that the mother is Rh-positive (as Rh-negative mothers would have been sensitized during the first pregnancy if the child was Rh-positive). The children being O, Rh-positive, explains why the second child would experience HDN due to the ABO incompatibility, as O blood type individuals can donate to any blood type, but they can only receive O type blood. Since the mother is AB, Rh-positive, she can receive blood from any group, but her antibodies can still react to the Rh or ABO antigens present in the child's blood if they are different from hers. However, the explanation provided does not perfectly align with the typical understanding of HDN, which primarily concerns Rh incompatibility. The correct explanation should focus on Rh factors, but the given choices and explanations suggest a mix-up in understanding.

A Woman's First Pregnancy Is Normal but Her Second Pregnancy