Pregnancy leg cramps may be caused by physiological phenomena, calcium deficiency during pregnancy and other reasons. 1. Physiological phenomenon: with the increase of pregnancy weeks, pregnant women bearing weight will also increase, when pregnant women are in a state of exertion, such as standing for a long time, too much walking, will increase the metabolism of lactic acid in the muscles of the legs, which can trigger leg muscle soreness, spasm, causing leg cramps in pregnant women. Some pregnant women sleep in an improper posture, can also cause pregnant women leg cramps, and then when the legs are cold, may also cause leg muscle spasm, and the phenomenon of leg cramps. 2. Calcium deficiency during pregnancy: Calcium needed for fetal growth and development during pregnancy is absorbed from the mother’s body, and with the increase in the number of weeks of pregnancy and the demand will increase, which can lead to a lack of calcium in the mother’s body, and the phenomenon of leg cramps. Therefore, since the middle of pregnancy, it is recommended that pregnant women should take calcium supplements under the guidance of the doctor and increase the intake of calcium-containing foods, such as dairy products. Pregnant leg cramps need to go to the hospital and actively deal with under the guidance of the doctor.