Low back pain is a very common clinical symptom in women during pregnancy, and the possible causes of low back pain in pregnant women at different weeks of pregnancy are not exactly the same. When a pregnant woman is 37 weeks pregnant, it is already a full-term pregnancy, and the possible reasons for the symptoms of lumbago at this time include: 1. Pregnancy aura symptoms, many pregnant women start to pelvis before delivery, and the fetal head will stimulate the back wall of the pelvic cavity after pelvic entry, causing the symptoms of lumbago. This symptom is often accompanied by a feeling of falling abdomen, when this symptom occurs, pregnant women should go to the hospital as soon as possible, prenatal examination, to further clarify the diagnosis, to prepare for admission to hospital for delivery at any time. 2, osteoporosis, insufficient calcium supplementation during pregnancy, so that the loss of bone calcium causes osteoporosis, is also the main cause of symptoms of lumbago during pregnancy, this symptom usually starts from 7-8 months of pregnancy This symptom usually starts from the 7th to 8th month of pregnancy and lasts until the full term of pregnancy.