The causes of placental abruption may be related to diseases, external factors, and sudden decrease in intrauterine pressure, but the pathogenesis has not yet been clarified. The patient usually suffers from vaginal bleeding, abdominal pain and other symptoms. 1. Disease: when pregnant women suffer from hypertension, severe pre-eclampsia, chronic kidney disease, etc., due to disease causes can cause arterial spasm or hardening, resulting in capillary rupture bleeding, so that the placenta and uterine wall separation. 2. External factors: Placental abruption may be induced when the pregnant woman’s abdomen is impacted, when she has a violent sexual life movement, or when the fetal position is corrected. 3. Sudden decrease of intrauterine pressure: it often occurs when there is too much amniotic fluid, when the uterus contracts suddenly; in twin pregnancies, when the first baby is delivered too quickly; when the membranes rupture prematurely before the full term of the fetus. Placental abruption is usually characterized by vaginal bleeding, sudden onset of persistent abdominal pain, which may be accompanied by increased uterine tone and uterine pressure. It is important to go to the hospital for treatment when these symptoms occur. The onset of placental abruption is rapid, and if not treated in time, it may put the life of the mother and the fetus at risk.