Back pain in late pregnancy is not necessarily a precursor to labor. It may also be related to certain physiological factors, disease factors and lack of nutritional elements, which need to be combined with the specific situation of the pregnant woman. 1, labor precursors: if after entering the prenatal period lumbar pain, accompanied by lumbar acidity, the feeling of wanting to relieve stool, during which there may be increased leucorrhea secretions, blood or amniotic fluid outflow, and over time, combined with abdominal tightness, hardness, and regularity, generally about 3 paroxysms in 10 minutes, is a more accurate signs of labor. In addition, it should also be noted that premature back pain is a signal that the fetus has entered the pelvis in advance; 2, physiological factors: in late pregnancy, women’s weight will increase significantly, intensifying the load on the lumbar spine, coupled with the increase in the size of the uterus, the forward protrusion, the body’s center of gravity will also increase the rear support tissues and lumbar intervertebral disc weight bearing, thus leading to back pain is obvious, this situation is not a harbinger of imminent delivery; 3, disease factors: pregnant women themselves suffer from herniated disc, scoliosis, degenerative spinal disease, chronic back pain, etc., will aggravate the symptoms of back pain during pregnancy, which is also not an omen of birth; 4, lack of nutrients: in late pregnancy, due to the rapid development of the fetus, pregnant women are prone to lack of various nutrients and minerals, especially calcium, vitamins and iron. Once lacking, it is easy to cause back pain, back pain, need to timely supplement the corresponding nutrients, but this back pain has nothing to do with the imminent birth, can not be used as a sign of imminent birth.