Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Rh Incompatibility ?
    ### Response:
    A difference in blood type between a pregnant woman and her baby causes Rh incompatibility. The condition occurs if a woman is Rh-negative and her baby is Rh-positive.
                
When you're pregnant, blood from your baby can cross into your bloodstream, especially during delivery.
    