Rh incompatibility occurs mother and foetus when

Options

A. Both and Rh+ve
B. Both and Rh-ve
C. Mother in Rh+ve and factors in Rh-ve
D. Mother is Rh -ve and factors is Rh +ve

Answer

### Step-by-Step Solution:

1. **Understanding Rh Factor**: The Rh factor is a protein that can be present on the surface of red blood cells. Individuals who have this protein are considered Rh positive (Rh+), while those who do not are Rh negative (Rh-).

2. **Identifying the Condition**: Rh incompatibility occurs when an Rh- mother is carrying an Rh+ fetus. This situation arises when the mother has a different Rh factor than the fetus.

3. **Mechanism of Incompatibility**: If the fetus is Rh+ and the mother is Rh-, the mother's immune system may recognize the Rh+ blood cells from the fetus as foreign. This can lead to the mother producing antibodies against the Rh factor.

4. **Consequences of Rh Incompatibility**: The antibodies produced by the mother can cross the placenta and attack the fetal red blood cells, leading to hemolytic disease of the newborn. This condition can result in severe anemia, jaundice, and in extreme cases, miscarriage or stillbirth.

5. **Conclusion**: Therefore, Rh incompatibility occurs specifically when the mother is Rh negative and the fetus is Rh positive.

### Final Answer:
Rh incompatibility occurs when the mother is Rh negative and the fetus is Rh positive.

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