Low back pain in early pregnancy may be caused by physiological factors such as fluctuating hormone levels and sedentary lifestyle. If accompanied by other physical discomfort, it should be considered as a result of ectopic pregnancy, preeclampsia and other diseases. 1. Physiological factors: pregnant women in early pregnancy, due to the body of estrogen and progesterone levels abnormally high, may lead to lumbosacral ligament laxity or edema, will lead to patients with back pain. If pregnant women sit for a long time, stand for a long time, or overwork, they may also suffer from back pain. 2. Ectopic pregnancy: Ectopic pregnancy may be caused by tubal inflammation, tubal dysplasia, contraceptive failure, smoking, multiple sexual partners and other factors. Patients may have abdominal pain, vaginal bleeding, anal swelling, and some patients may have back pain. 3. Pre-eclampsia: The causes of pre-eclampsia include chromosomal abnormality of embryo, genital abnormality, endocrine abnormality, surgery, chemical stimulation and so on. Symptoms are lower abdominal pain, vaginal bleeding, low back pain, etc. If the amount of vaginal blood gradually increases, it may develop into inevitable miscarriage. Clinical causes of back pain in early pregnancy are many, it is recommended that patients seek medical attention to identify the cause of the disease in a timely manner, when the exclusion of physiological factors, you need to actively cooperate with the doctor to take relevant therapeutic measures.