Question

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

• 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 1

The correct option is B Mother is Rh -ve and father is Rh +ve.

Erythroblastosis fetalis also called hemolytic disease of the newborn, type of anemia in which the red blood cells (erythrocytes) of a fetus are destroyed in a maternal immune reaction resulting from a blood group incompatibility between the fetus and its mother. This happens during second pregnancy when the mother's immune system is already sensitized to Rh${}^{+}$ antigens present on the blood cells of the foetus during the first pregnancy. The Rh gene being dominant, the feotus will be Rh${}^{+}$ if anyone of the parent is Rh${}^{+}$.

So, the correct answer is "Mother is Rh-ve and father is Rh+ve."