Question

After examining the blood group of husband and wife, the doctor advised them not to have more
than one child. The blood groups of the couple are likely to be
A. Male Rh and female Rh-
B. Female Rh and male Rh-
C. Male Rh- and female Rh-
D. Male Rh and female Rh.

Answer 1

People having Rh factor ( Rh stands for the rhesus monkey, in which these antigens were first discovered ) on RBC are said to be Rh-positive. Rh incompatibility (mismatch) has been observed between the Rh-negative blood of a pregnant mother with Rh-positive blood of the foetus.

Complete step by step answer: An Rh-negative person, if exposed to Rh-positive blood, will form specific antibodies against the Rh antigen.
The Rh-negative mother is not usually exposed to the Rh-positive antigen of the foetus during the first pregnancy as the foetal and maternal blood are normally kept well separated by the placental barriers. However, at the time of the birth of a first child, there is a possibility of exposure of the maternal blood to small amounts of the Rh-positive blood from the foetus. In such cases, the mother prepares antibodies against the Rh antigens in her blood.
These antibodies could cross the placental barriers in subsequent pregnancies and cause hemolysis of the Rh-positive red blood cells of the foetus. This Condition is called erythroblastosis fetalis.
So, the correct answer to the given question is option A. Male Rh and female Rh-negative.

Note: The condition of the newborn which is suffering from anaemia and jaundice is called HDN that means haemolytic disease of newly born. Erythroblastosis fetalis can be prevented by injecting the Rh-negative mother with an antibody preparation (anti-Rh antibodies) against the Rh factor immediately after the birth of each Rh-positive baby.