Effect of Pregnancy On The Venous System

Dan SteffesMar 7, '14

During pregnancy, many hormonal changes occur in the body that have a profound effect on the veins. Blood volume increases between 40% to 50%, while increased amounts of progesterone cause the vein walls to dilate and become less elastic. 

The pressure of the fetal head in the pelvis can compress the iliac veins and obstruct venous outflow from the legs. As the baby grows, the uterus enlarges and applies pressure on important veins that return blood to the heart. This pressure can cause a slowing of the blood flow and valve damage, resulting in swelling, leg discomfort, and even varicose veins. 

A pregnant woman's feet and legs may start to swell after sitting or standing for only a short time. In principle, this is a completely normal symptom. However, if your feet are already swollen when you get up in the morning, consult your doctor. While these symptoms may subside after delivery, with each subsequent pregnancy, they are less likely to completely disappear.