Low back pain in pregnant women may be caused by physiological factors, osteoporosis, lumbar muscle strain, lumbar intervertebral disc herniation and other factors. 1. Physiological factors: with the growth of the fetus, the uterus gradually increases in size, and the weight of the pregnant woman will also increase, which will increase the load on the waist, standing or walking for a long time, physiological lumbar pain will occur, and the symptoms of the pain can be alleviated after reasonable rest. 2. Osteoporosis: In the middle and late stages of pregnancy, the fetus absorbs more calcium, and the lack of calcium in the pregnant woman’s body can easily induce osteoporosis, which can cause lumbar soreness and lumbago. 3. Lumbar muscle strain: During pregnancy, catching a cold in the lumbar area or excessive bending may induce lumbar muscle strain, which may lead to lumbar pain, and there will be localized pressure points when pressed. 4. Herniated lumbar intervertebral discs: Pregnant women with underlying diseases such as herniated lumbar intervertebral discs may be aggravated by herniated lumbar intervertebral discs after pregnancy, resulting in lumbar pain, accompanied by lower extremity pain and numbness of the lower extremities and other symptoms. Pregnant women with prolonged symptoms of lumbar pain are advised to consult a doctor for examination, to clarify the causative factors, and to carry out reasonable treatment under the guidance of the doctor.