What causes swollen feet during pregnancy?

It is quite common for pregnant women to experience edema after a period of pregnancy. This is mainly related to certain disorders in the body's water circulation. At this time, pregnant women are prone to swollen feet and hands. At this time, pregnant women should exercise more, pay attention to the body's blood circulation, massage appropriately, maintain adequate rest, and never stand for long periods of time.

1. Blood volume gradually increases

After pregnancy, the pregnant woman's blood volume begins to gradually increase from the 6th week of pregnancy, reaches a peak at 34 weeks, and remains at this level until two weeks after delivery, when it returns to the pre-pregnancy level. Blood volume can increase by about 40% compared to the non-pregnant period, so as blood volume increases, interstitial fluid will also increase.

2. Plasma osmotic pressure during pregnancy is lower than that during non-pregnancy

Because when blood increases, the increase in plasma is greater than the increase in blood cells, etc., the blood components will be relatively diluted and the relative concentration of plasma albumin will be lower than that in the non-pregnant period. Plasma albumin is the main component that maintains plasma osmotic pressure. Plasma osmolality is lower during pregnancy than during non-pregnancy. This makes it easy for water in the blood to penetrate into the interstitial fluid, causing lower limb edema.

3. The uterus enlarges after pregnancy, increasing the pressure in the pelvis

After pregnancy, the uterus enlarges, which increases the pressure in the pelvis, thereby affecting the venous blood flow in the lower limbs. This is also one of the important reasons for lower limb edema. If the swelling during pregnancy is relieved after rest or sleep, it is physiological and there is no need to worry.

In the first few days after delivery, excess water in the body can be discharged through frequent urination and heavy sweating, and the drainage rate is proportional to the severity of edema. Some expectant mothers' feet will return to their original size after giving birth, while others will grow larger than before. This is because the relaxin in the body not only relaxes the pelvic joints to facilitate the delivery of the fetus from the birth canal, but also expands the feet.