The mechanism of low back pain during pregnancy is not completely clear, and the possible causes include miscarriage with aura; hormonal changes and relaxin affecting the pelvic ring laxity, sacroiliac joints, pubic symphysis instability; fetal growth makes the spinal extensor muscles to be pulled, lumbar vertebrae anterior convexity, lumbar muscle strain resulting in low back pain; fetal and uterine nerve compression resulting in low back pain. 1. Pre-eclampsia: During pregnancy, when a pregnant woman has a pre-eclampsia, she may experience lumbago, which is manifested as soreness and pain in the lumbosacral region, accompanied by vaginal bleeding and pain in the lower abdomen and other symptoms. 2. Hormone levels rise during pregnancy, while relaxin levels increase, ligamentous joints, especially the pelvic ligaments will be relatively loose, joint pain symptoms may occur, manifested as low back pain. 3. When the uterus enlarges during pregnancy, the spine and lumbar muscles are pulled, the lumbar vertebrae are convex, and the lumbar muscles are strained, which may cause low back pain; in addition, the enlarged uterus compresses the sciatic nerve, which may also cause symptoms of low back pain. During pregnancy, prolonged low back pain is recommended to seek medical attention if it is not relieved on its own.