A severe backache at 39 weeks of pregnancy does not necessarily mean that labor is imminent. If it is a sudden severe back pain, accompanied by obvious regular contractions and vaginal fluid, it can be considered that there is a premonitory labor. However, if it is only persistent back pain, consider other reasons related to: First, pregnancy factors: 1, the uterus is larger: 39 weeks of pregnancy for the late pregnancy, due to the increased uterine compression of the lumbar vertebrae, which can easily lead to cause lumbar pain; 2, hormonal factors: the placenta will be released during pregnancy, relaxin, relaxin will make the skeletal muscle relaxation phenomenon, caused by the lower lumbar soreness. Second, disease factors: 1, urological diseases: such as pyelonephritis, ureteral stones, etc., will lead to lumbar kidney area pain, can be accompanied by urinary pain, urinary urgency and other manifestations; 2, gynecological diseases: such as chronic pelvic inflammatory disease, chronic appendicitis, etc., the patient, in addition to lumbosacral pain, usually accompanied by pain in the lower body, the secretion of the odor, etc.; 3, lumbar diseases: such as lumbar muscle strain, lumbar disc hyperplasia, etc., manifested in the Soreness and discomfort in the lumbar region, at this time should be in the gynecologist’s advice under the appropriate activities to ease the discomfort symptoms. Attention to pregnant women with back pain, should avoid exertion, pay attention to rest; reasonable diet, balanced nutrition, eat more fresh fruits and vegetables; smooth mentality, to avoid tension, panic and other bad emotions; if the symptoms of back pain has not been relieved and the symptoms worsened, you need to go to the hospital to do the appropriate examination, find out the reasons for it, and then according to the situation of the symptomatic treatment. If there is regular stomach pain, hardness and tightness, which may be accompanied by back pain, or redness or breaking of amniotic fluid, it means that labor is imminent and you need to go to the hospital as soon as possible.