An Rh-positive male gets married to an Rh-negative female. During their second pregnancy, which of the following events would be observed ?

Options

A. Rh incompatibility disease
B. Erythroblastosis foetalis
C. Muscular dystrophy
D. Both ( A) and (B)

Answer

To solve the question regarding the events observed during the second pregnancy of an Rh-positive male and an Rh-negative female, we can follow these steps:

### 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 with this protein are classified as Rh-positive, while those without it are Rh-negative.

2. **First Pregnancy**:
- In the first pregnancy, the Rh-negative mother carries an Rh-positive fetus. The blood of the mother and fetus is separated by the placenta, preventing the mixing of blood. Therefore, the mother does not develop antibodies against the Rh factor during this pregnancy.

3. **Potential Exposure During Delivery**:
- At the time of delivery, there is a possibility that a small amount of Rh-positive fetal blood may enter the mother's bloodstream. This exposure can lead to the mother’s immune system recognizing the Rh-positive cells as foreign and producing antibodies against the Rh factor.

4. **Second Pregnancy**:
- In the second pregnancy, if the fetus is again Rh-positive, the mother, now having developed antibodies against the Rh factor from the first pregnancy, can pass these antibodies through the placenta to the fetus.

5. **Consequences of Antibody Transfer**:
- The Rh antibodies from the mother can attack the red blood cells of the Rh-positive fetus, leading to a condition known as **Erythroblastosis Fetalis**. This condition can cause severe anemia and jaundice in the fetus, as the antibodies destroy the fetal red blood cells.

6. **Conclusion**:
- Therefore, during the second pregnancy, the events that would be observed include both Rh incompatibility disease and erythroblastosis fetalis. Thus, the correct answer is **both A and B**.

### Final Answer:
The observed events during the second pregnancy would be **both A (Rh incompatibility disease) and B (erythroblastosis fetalis)**.

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