Question

If the mother is $R{h}^{-ve}$ and father is $R{h}^{+ve}$, which of the following $R{h}^{+ve}$ child is normally not affected?

• A. First
• B. Male child
• C. Female child
• D. Second

Answer 1

Answer: (A)

Rh incompatibility usually isn't a problem if it's the mother's first pregnancy because, unless there's some sort of abnormality, the fetus's blood does not normally enter the mother's circulatory system during the course of the pregnancy. However, during second child, the mother's and baby's blood can intermingle. If this happens, the mother's body recognizes the Rh protein as a foreign substance and might begin making antibodies (protein molecules in the immune system that recognize, and later work to destroy foreign substances) against the Rh proteins. Rh antibodies are harmless until the mother's second or later pregnancies. If she is ever carrying another Rh-positive child, her Rh antibodies will recognize the Rh proteins on the surface of the baby's blood cells as foreign, and pass into the baby's bloodstream and attack those cells. This can lead to swelling and rupture of the baby's RBCs. A baby's blood count can get dangerously low when this condition, known as a haemolytic or Rh disease of the newborn, happens.

Therefore, the correct answer is option B.