A 26-year old primigravida at 32 weeks of gestation experienced faintness and nausea in lying down and recovers after turning on her side or getting up. These symptoms can be attributed to which of the following?
**Core Concept**
The underlying principle in this question is related to the physiological changes that occur during pregnancy, particularly those affecting the cardiovascular and autonomic nervous systems. The symptoms described, such as faintness and nausea in a recumbent position, suggest a condition that worsens with increased venous pooling and improves with positional changes.
**Why the Correct Answer is Right**
The symptoms described are characteristic of supine hypotension syndrome, a condition that occurs when the pregnant uterus compresses the inferior vena cava, leading to decreased venous return to the heart and subsequent hypotension. This condition is more likely to occur in the supine position due to the weight of the pregnant uterus compressing the vena cava. The autonomic nervous system's response to this compression leads to peripheral vasodilation, which exacerbates the hypotension.
**Why Each Wrong Option is Incorrect**
* **Option A:** Orthostatic hypotension is a condition characterized by a sudden drop in blood pressure upon standing, which can be exacerbated by pregnancy. However, the symptoms described in the question are more specific to the supine position.
* **Option B:** Preeclampsia is a condition characterized by high blood pressure and proteinuria during pregnancy. While it can cause symptoms such as nausea and faintness, it is not directly related to positional changes.
* **Option C:** Anemia is a condition characterized by a decrease in red blood cells or hemoglobin. While it can cause fatigue and weakness, it is not directly related to positional changes or the specific symptoms described in the question.
**Clinical Pearl / High-Yield Fact**
It is essential for healthcare providers to be aware of the potential for supine hypotension syndrome, particularly in pregnant patients at 28-36 weeks of gestation. Turning the patient onto her side or using a wedge pillow can help alleviate symptoms and prevent complications.
**Correct Answer: C. Anemia is a condition characterized by a decrease in red blood cells or hemoglobin. While it can cause fatigue and weakness, it is not directly related to positional changes or the specific symptoms described in the question.