If oxyhemoglobin dissociation curves are drawn for maternal and fetal hemoglobin, which of the following is true ?

Options

A. Maternal curve will be on the right side
B. Fetal curve will be on the right side
C. Both will overlap each other
D. Maternal curve will be on left side

Answer

To solve the question regarding the oxyhemoglobin dissociation curves for maternal and fetal hemoglobin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Oxyhemoglobin Dissociation Curve**:
- The oxyhemoglobin dissociation curve plots the partial pressure of oxygen (x-axis) against the percent saturation of hemoglobin with oxygen (y-axis). It typically has a sigmoidal (S-shaped) curve.

2. **Identify the Curves for Maternal and Fetal Hemoglobin**:
- The curve for fetal hemoglobin (HbF) is generally positioned to the left of the curve for adult hemoglobin (HbA). This means that at any given partial pressure of oxygen, fetal hemoglobin will be more saturated with oxygen than maternal hemoglobin.

3. **Comparing Affinity for Oxygen**:
- Fetal hemoglobin has a higher affinity for oxygen compared to maternal hemoglobin. This is crucial for fetal development, allowing the fetus to extract oxygen from maternal blood efficiently.

4. **Positioning of the Curves**:
- Since fetal hemoglobin has a higher affinity for oxygen, its dissociation curve will be to the left of the maternal hemoglobin curve. Therefore, the maternal hemoglobin curve will be on the right side when compared to the fetal hemoglobin curve.

5. **Evaluating the Options**:
- Option 1 states that the maternal curve will be on the right side, which is true.
- Option 2 states that the fetal curve will be on the right side, which is false.
- Option 3 states that both curves will overlap, which is also false.
- Option 4 states that the maternal curve will be on the left side, which is incorrect.

6. **Conclusion**:
- The correct answer is Option 1: the maternal curve will be on the right side compared to the fetal hemoglobin curve.