There are several causes of cramps in late pregnancy: 1. In late pregnancy, as the size of the fetus increases, the mother and fetus have an increased demand for nutrients, especially protein, calcium and micronutrients. If the pregnant woman’s dietary intake is insufficient, this may lead to cramps due to calcium or other micronutrients deficiency.2. In late pregnancy, due to the increase in the pregnant woman’s weight, it leads to the muscles of the lower limbs being more prone to fatigue for the same amount of exercise time, thus inducing cramps.3. In late pregnancy, due to the increase in the size of the fetus, the inferior vena cava is compressed, leading to obstruction of venous return in both lower limbs, causing swelling in both lower limbs, thus This can cause muscle cramps. Therefore, when cramps occur, it is necessary to go to a gynecologist or obstetrician and ask a professional doctor for guidance on treatment, supplementation of micronutrients if necessary, resting in a flat position and elevating the affected limbs will help eliminate cramps.