Which of the following parameters are not increased during pregnancy :
**Core Concept**
During pregnancy, various physiological changes occur to accommodate the growing fetus and prepare the mother's body for childbirth. These changes involve alterations in maternal cardiovascular, respiratory, and renal systems, among others.
**Why the Correct Answer is Right**
One of the key changes during pregnancy is an increase in cardiac output, which is essential for meeting the increased metabolic demands of the mother and the fetus. This is achieved through an increase in heart rate and stroke volume. Additionally, plasma volume increases by approximately 40-50% above non-pregnant levels, which helps to maintain blood pressure. However, total blood volume increases by only 40-50%, resulting in a relative decrease in hematocrit levels. This decrease in hematocrit levels is due to the increase in plasma volume and is a normal finding in pregnancy.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not necessarily increased - actually, serum levels of albumin decrease during pregnancy due to the increase in plasma volume.
* **Option B:** Increased - the cardiac output increases by approximately 30-50% above non-pregnant levels.
* **Option C:** Increased - the plasma volume increases by approximately 40-50% above non-pregnant levels.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that a decrease in hematocrit levels is a normal finding in pregnancy, and it's not a cause for concern unless it's accompanied by symptoms of anemia.
**Correct Answer: A. Serum albumin levels are not necessarily increased during pregnancy.