This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
The consequences of Rh incompatibility are not serious during first pregnancy because 
Select and explain. 
A. Antibodies are not able to cross placenta, B. Antibody titre is very low during primary response, C. IgG generated is ineffective against fetal red ceell, D. None
A: Antibodies are not able to cross placenta
Answer: A: Antibodies are not able to cross placenta 
Explanation: Initially in mother IgM antibodies are formed that does not cross placenta and subsequently during next exposure IgG antibody are formed which can cross placenta and hemolysis will occur.