Calf pain during pregnancy may be caused by calcium deficiency, prolonged standing and poor blood circulation. 1. Calcium deficiency: with the increase of pregnancy time, especially in the middle and late stages of pregnancy, the fetus grows and develops faster and needs more nutrient intake, while the pregnant woman’s intake of nutrients is insufficient, which may lead to calcium deficiency, triggering the symptoms of calf pain, and in severe cases, leg cramps may also occur. 2. Standing for a long time: some pregnant women stand for a long time, due to the body is too heavy, the leg force is more serious, may also lead to calf pain symptoms. 3. Poor blood circulation: With the increase of pregnancy time, the uterus will press the inferior vena cava to block the blood return, which will lead to poor blood circulation and cause calf pain symptoms. Clinical causes of calf pain during pregnancy are many, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease, and then under the guidance of the doctor for the cause of the treatment.