Question

In which of the following situations, is there a risk factor for children of incurring erythroblastosis foetalis?

• A. Mother is ${Rh}^{+}$ and father is ${Rh}^{+}$
• B. Mother is ${Rh}^{+}$ and father is ${Rh}^{-}$
• C. Mother is ${Rh}^{-}$ and father is ${Rh}^{-}$
• D. Mother is ${Rh}^{-}$ and father is ${Rh}^{+}$

Answer 1

Answer: (D)

Mother is ${Rh}^{-}$ and father is ${Rh}^{+}$

The Rh- factor has great significance in child birth. An Rh-ve woman married with Rh+ve man becomes sensitized by carrying a Rh+ve cchild with in her body. This is because an Rh-ve person, if exposed to Rh+ve blood, will form specific antibodies against the Rh antigens. This is observed in case of Rh-ve blood of a pregnant mother with Rh+ve blood of the foetus. Rh antigens of the foetus do not get exposed to the Rh-ve blood of the mother in the first pregnancy as the two bloods are well separated by placenta. However, during the delivery of second child, there is a possibility of the exposure of material blood to the small amounts of the Rh+ve blood from the foetus. In such cases, mother starts preparing antibodies against Rh antigen in her blood. In case of subsequent pregnancies, the Rh antibodies from the mother (Rh-ve) can leak into the blood of foetus (Rh+ve) and destroy foetal RBCs. This could be fatal to the foetus or could cause severe anemia and jaundice to the body. This condition is known as erythroblastosis foetalis.

Hence, correct answer is option D.