Leg cramps are very common during pregnancy, and there are several mechanisms that produce this condition: 1. They may be caused by osteoporosis. This condition is most common and tends to occur in the middle and late stages of pregnancy. The most common reason for this is the lack of calcium in the mother’s body due to the rapid growth of the fetus, which can lead to osteoporosis, which may produce some muscle twitching in the lower limbs. 2. It may be caused by peripheral nerve lesions. During pregnancy, the rapid increase in abdominal circumference can lead to very large changes in the physiological curvature of the patient’s lumbar spine. The company’s main business is to provide a wide range of products and services to its customers. Some patients are lazy during pregnancy, unwilling to exercise or doctor’s orders need to be bedridden for a long time. This is not enough exercise may lead to disuse atrophy of the muscles of the lower limbs, once the lower limbs in the force may produce the cramps due to lack of muscle strength. Finally, this condition may also be caused by cold in the lower limbs.