Cause of ‘Erythroblastosis fetalis' may be

Options

A. destruction of RBC
B. Bleeding
C. Diapedesis
D. Haemophilia

Explanation

### Step-by-Step Solution:

1. **Understanding Erythroblastosis Fetalis**:
- Erythroblastosis fetalis is a condition that occurs in a fetus when there is an incompatibility between the blood types of the mother and the fetus.

2. **Identifying the Blood Types**:
- The condition typically arises when the mother is Rh-negative (lacking the Rh factor) and the fetus is Rh-positive (having the Rh factor).

3. **Mechanism During Delivery**:
- During childbirth (parturition), the maternal blood and fetal blood can come into contact. This exposure can occur when the placenta separates from the uterine wall.

4. **Antibody Production**:
- When the Rh-negative mother’s blood comes into contact with the Rh-positive fetal blood, her immune system recognizes the Rh factor as foreign and starts producing antibodies against it.

5. **Subsequent Pregnancies**:
- If the mother becomes pregnant again with another Rh-positive fetus, the antibodies produced during the first pregnancy can cross the placenta and attack the fetal red blood cells (RBCs).

6. **Destruction of Fetal RBCs**:
- The maternal antibodies lead to the destruction of the fetal RBCs, which can cause severe anemia and other complications in the fetus, hence the name erythroblastosis fetalis.

7. **Conclusion**:
- Therefore, the cause of erythroblastosis fetalis is the incompatibility between Rh-negative maternal blood and Rh-positive fetal blood, leading to the destruction of fetal red blood cells due to maternal antibodies.