Placental abruption is a maternal emergency, the reasons mainly include the following: 1, vascular factors: such as patients with hypertension, patients with kidney disease, the blood vessels are more fragile; 2, mechanical factors: like trauma, direct external impact on the abdomen; external inversion when the fetal position is abnormal is also prone to placental abruption; the umbilical cord is too short or the umbilical cord is wrapped around the neck, the rapid descent of the fetal dew during delivery may also lead to placental abruption; 3 When the fetal membranes rupture prematurely, a large amount of amniotic fluid suddenly gushes out, which will also lead to a smaller uterine cavity and cause placental abruption; 4, some patients are used to smoking and drug use, such as cocaine, which will also affect the vascular fragility; 5, it is related to the age of the pregnant woman and the number of births, the older the chance of placental abruption; in addition, it is more important that the more the number of births, the risk of placental abruption increases geometrically, so the more the number of births and the older the mother, the more the risk of placental abruption increases geometrically. The higher the number of deliveries and the older the mother is, the higher the risk of delivery.