This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'Maximum chances of ABO isoimmunization is seen in? \nSelect and explain. \nA. O+VE Mother to A+VE child, B. O+VE mother to B+VE child, C. A+VE mother to 0+VE child, D. B+VE mother to O+VE child', 'role': 'user'}, {'content': "Answer: A \nExplanation: TEXT BOOK OF PATHOLOGY HARSHMOHAN 6THEDITION PG NO 341 HDN due to ABO incompatibility. About 20% pregnancies with ABO incompatibility between the mother and the foetus develop the HDN. Naturally-occurring anti-A and anti-B antibodies' which are usually of IgM class do not cross the placenta, while immune anti-A and anti-B antibodies which are usually of IgG class may cross the placenta into foetal circulation and damage the foetal red cells. ABO HDN occurs most frequently in infants born to group O mothers who possess anti-A and/or anti-B IgG antibodies. ABO-HDN differs from Rh(D)-HDN, in that it occurs in first pregnancy, Coombs' (antiglobulin) test is generally negative, and is less severe than the latter. <\\p>", 'role': 'assistant'}]