It does not matter if a woman has back pain in the almost third trimester of pregnancy, if the pain is mild and there is no vaginal bleeding. The main reason is that after pregnancy, due to the growth and development of the embryo in the uterine cavity, the uterus will also increase in size, which will compress the nerves in the lower back, and the woman will experience back pain. The back pain can be relieved gradually by appropriate bed rest and massage of the lower back. If there is a small amount of vaginal bleeding, most of the cases are combined with pre-eclampsia, women need to go to the hospital for gynecological ultrasound, blood chorionic gonadotropin and progesterone measurement, progesterone value is low, progesterone drugs can be actively given for fetal preservation. If the embryo develops well after the examination and there is no abnormality, the woman’s back pain will be properly relieved after the third trimester.