If you have thigh pain in the fifth month of pregnancy, consider that the enlarged uterus is pressing on the inferior vena cava reflux, resulting in obstruction of the reflux and causing thigh pain, or the fetus is pressing on the nerves during the fetal process, resulting in neuropathic pain, or in the middle and late stages of pregnancy, due to the rapid growth of the fetus, the pregnant woman is prone to bone or thigh pain due to calcium deficiency. These causes are divided into several kinds. During this period, try to pay attention to bed rest, do not overexert yourself, do not stand for a long time, it is best to take rest in the left side of the bed, which is conducive to blood circulation and reduce the pain caused by obstructed reflux. During this period should also be appropriate to supplement calcium, eat more food with high calcium content, can eat more kelp, seaweed, shrimp, usually should also be more sunshine to promote the absorption of calcium.