The leg cramps of pregnant women in the morning may be caused by the following reasons: 1, there may be the influence of insufficient exercise. There are many pregnant women who do not move often during pregnancy due to pregnancy reaction or weakness, and when they suddenly go down to the ground to carry weight, it may produce lower limb cramps. 2. There may be the influence of cold. The woman’s legs are covered with clothes and blankets at night, and when she gets up in the morning and goes down to the ground, it may lead to muscle cramps due to cold. 3. There may be electrolyte disorders in the body. Many pregnant women have morning sickness, and this vomiting, combined with loss of appetite, may lead to electrolyte disorders in the body, followed by leg cramps in the morning. 4, there may be osteoporosis. The rapid growth of the fetus may cause a lack of calcium in the mother’s body, leading to osteoporosis, which may lead to leg cramps in the morning.