Why do swelling and varicose veins often develop in the legs during pregnancy?

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human fetus; prenatal development — prenatal development An ultrasound image of a human fetus.

During pregnancy, swelling and the development of varicose veins in the legs occur primarily due to changes in the circulatory system and mechanical pressure. As the uterus enlarges, it exerts pressure on the large blood vessels in the pelvis, which slows the rate of blood flow in the lower extremities and increases venous pressure. This leads to blood stasis, or stagnation, in the legs.1

These physiological changes are also influenced by the significant increase in circulating estrogen and progesterone hormones. Furthermore, the growing uterus compresses lymphatic vessels in the pelvis, impairing lymphatic drainage from the legs and contributing to the swelling and distention of the feet and lower limbs. While some fluid collection is common near the end of pregnancy, it is important to note that sudden or generalized swelling can be a sign of preeclampsia, a serious medical condition that requires professional evaluation.1