Aortocaval compression starts to become significant in a normal pregnancy at how many weeks EGA?

Aortocaval compression starts to become significant in a normal pregnancy at how many weeks EGA?

• A. 5 weeks
• B. 10 weeks
• C. 15 weeks
• D. 20 weeks

Answer: (D)

As the pregnancy progresses, the enlarging uterus begins to press on major abdominal vessels, especially when the mother is lying on her back. Significant aortocaval compression tends to begin around 20 weeks of gestation, when the uterus rises above the pelvic brim and starts to impinge on the inferior vena cava and aorta. Before about 20 weeks, the uterus is still mostly within the pelvis, so compression is minimal. After 20 weeks, the risk increases, particularly in the supine position, because venous return to the heart is reduced and uteroplacental blood flow can be affected. Placing the patient in the left lateral tilt helps relieve this compression.

As the pregnancy progresses, the enlarging uterus begins to press on major abdominal vessels, especially when the mother is lying on her back. Significant aortocaval compression tends to begin around 20 weeks of gestation, when the uterus rises above the pelvic brim and starts to impinge on the inferior vena cava and aorta. Before about 20 weeks, the uterus is still mostly within the pelvis, so compression is minimal. After 20 weeks, the risk increases, particularly in the supine position, because venous return to the heart is reduced and uteroplacental blood flow can be affected. Placing the patient in the left lateral tilt helps relieve this compression.