In the third trimester, placing a pregnant patient in a supine position may have what effect on venous return to the heart?

In the third trimester, placing a pregnant patient in a supine position may have what effect on venous return to the heart?

• A. May increase the amount of blood returned to the heart
• B. No effect on venous return
• C. May decrease the amount of blood that returns to the heart
• D. May cause tachycardia

Answer: (C)

When a pregnant patient is in the third trimester, lying on the back can allow the enlarged uterus to press on the inferior vena cava. That compression reduces the amount of venous blood returning to the heart (lower preload), which decreases cardiac output and can lower blood pressure or cause dizziness. To improve venous return, place the patient on her left side or tilt the uterus off the IVC. Tachycardia might occur as the body tries to compensate for lower blood pressure, but the direct effect of the supine position is a decrease in venous return.

When a pregnant patient is in the third trimester, lying on the back can allow the enlarged uterus to press on the inferior vena cava. That compression reduces the amount of venous blood returning to the heart (lower preload), which decreases cardiac output and can lower blood pressure or cause dizziness. To improve venous return, place the patient on her left side or tilt the uterus off the IVC. Tachycardia might occur as the body tries to compensate for lower blood pressure, but the direct effect of the supine position is a decrease in venous return.