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

Options

A. Mother is Rh -ve and father is Rh -ve
B. Mother is Rh -ve and father is Rh + ve
C. Mother is Rh + ve and father is Rh + ve
D. Mother is Rh +ve and father is Rh - ve

Answer

B

Explanation

During first pregnancy, Rh antigens of the foetus do not get exposed to the Rh `-ve` blood of the mother as the two blood are well separated by placenta. However, at the time of delivery, there are chances of exposure of the materal blood to small amounts of Rh `+ve` blood of the foetus. The mother's body starts perparing antibodies against Rh antigens in her blood. In case of subsequent pergancies, the Rh antibodies from the mother can leak into the blood of the Rh `+ve` foetus and destory the foetal RBCs. This could be fatal for the foetus or could cause servere anaemia and jaundice. This condition is called erythroblastosis foetails.