The most common causes of placental abruption are uteroplacental vasculopathy, elevated uterine venous pressure, intrauterine infection, etc., as follows. 1. Uteroplacental vascular lesions: Placental abruption often occurs in pregnant women with preeclampsia, chronic kidney disease and chronic hypertension. 2. Elevated uterine venous pressure: Pregnant women in late pregnancy and on the verge of labor are lying on their backs for a long time, which results in the uterus pressing on the inferior vena cava, leading to elevated venous pressure, uterine venous stasis, reduced return blood volume, decreased blood pressure, and ultimately leading to the venous beds of the pregnant women to be stagnant and ruptured, resulting in placenta previa. 3. Intrauterine infection: Infection in the uterus of pregnant women leads to thrombosis, which can easily lead to placental abruption. Therefore, it is recommended that pregnant women should follow the doctor’s instructions during pregnancy and have regular checkups in order to prevent the phenomenon of placental abruption.