During mid-pregnancy, which cardiovascular change is typically observed in the mother?

• A. Decrease in pulse rate.
• B. Increase in pulse rate.
• C. Increase in blood pressure.
• D. Decrease in red blood cell production.

Answer: (A)

During mid-pregnancy, the mother's cardiovascular system adapts to support the growing fetus. Cardiac output rises because both the heart rate and stroke volume increase, while systemic vascular resistance falls due to vasodilation. This means the pulse rate tends to rise, producing mild tachycardia, rather than decreasing. Blood pressure often drops in the second trimester because of the lower vascular resistance, not because the heart is beating more slowly. Additionally, red blood cell production increases to accompany the expanded blood volume, though plasma volume increases more, leading to physiologic anemia of pregnancy. So, the typical change you’d expect is an increase in pulse rate.