During pregnancy, which blood pressure change is typical?

• A. Systolic blood pressure significantly increases
• B. Diastolic blood pressure decreases 10 to 15 mmHg overall
• C. Systolic and diastolic blood pressures both rise
• D. Blood pressure remains stable and unchanged

Answer: (B)

During pregnancy, hormonal changes lead to vasodilation and a drop in systemic vascular resistance, while plasma volume expands and cardiac output rises. The net effect is a fall in blood pressure, especially in the diastolic value, in the mid-pregnancy period. Diastolic blood pressure typically decreases about 10 to 15 mmHg overall, while systolic pressure stays about at pre-pregnancy levels or may decrease only slightly. By the late third trimester, pressures generally return toward baseline.

This pattern explains why a diastolic drop of 10–15 mmHg is the typical change. Rises in systolic pressure, simultaneous rises in both numbers, or no change are not characteristic of uncomplicated pregnancy.