The exact pathogenesis of placental abruption is unclear, and may be related to vascular lesions, mechanical factors, and sudden decrease in intrauterine pressure. 1. Vascular lesions: pregnant women with hypertensive disorders of pregnancy, chronic kidney disease or systemic vascular lesions are susceptible to capillary rupture and hemorrhage, and the blood pressure builds up between the uterus and the placenta, leading to separation of the placenta from the uterine wall. 2. Mechanical factors: impact on the abdomen or external inversion surgery can induce placental abruption. 3. Sudden decrease of pressure in the uterine cavity: amniotic fluid flows out too fast when the membranes rupture, and in the case of a twin pregnancy, the first child is delivered too fast, which leads to a sudden decrease of pressure in the uterine cavity, sudden contraction of the uterus, and abrupt abruption of the placenta. Placental abruption is a serious complication of pregnancy that develops rapidly and can jeopardize the safety of the mother and child if not treated in time. Pregnant women who experience symptoms such as abdominal pain and vaginal bleeding in the middle to late stages of pregnancy need to seek prompt medical attention.