Knee pain during pregnancy may be caused by calcium deficiency, higher body weight of pregnant women, and cold knee joints. 1. Calcium deficiency: Because the fetus in the abdomen during pregnancy also needs a certain amount of calcium to promote the development of bones and teeth, and at the same time due to the human body’s ability to absorb calcium can not be supplied to the fetus in a timely manner, and pregnant women’s body blood flow, there may be a dilution of calcium caused by osteoporosis, which leads to a reduction in the toughness of the tissues of the knee joints, which causes the symptoms of knee pain. 2. Pregnant women weigh more: as pregnancy continues to increase, the fetus continues to develop pregnant women’s weight gradually increased, may increase the burden on the lower extremities of the knee joints, resulting in lower extremities of the knee joints around the tissues of the injury, causing knee pain. 3. Knee cold: due to the pregnancy of pregnant women less activity, and often feel the body heat, easy to pay no attention to keep warm so that the knee joints cold, causing the blood vessels around the knee joint contraction, poor blood circulation caused by knee pain. Women with knee pain during pregnancy should go to the hospital in time to clarify the cause of the problem and then under the guidance of the doctor to carry out targeted treatment.