The causes of low back pain during pregnancy are as follows: 1. Some pregnant women have symptoms of miscarriage and prolonged bed rest due to tension may also lead to low back pain, such pregnant women can moderate activities; 4, some pathological conditions may also be manifested as low back pain, such as preterm miscarriage, preterm labor, placental abruption, urinary system diseases, lumbar muscle sprain, disc protrusion, etc. can also be manifested as low back pain, so if the low back pain is obvious, you should promptly go to the hospital to find the cause of the cause for treatment.