After 20 weeks of gestation or during labor, the placenta in its normal position is partially or completely detached from the uterine wall before the delivery of the fetus, which is called placental abruption. Placental abruption is a serious complication in late pregnancy, with rapid onset and progression, which can endanger the life of mother and child if not treated in time. The incidence of placental abruption is 4.6‰ to 21‰ in China and 5.1‰ to 23.3‰ in foreign countries. The incidence is related to whether the placenta is carefully examined after delivery. Some patients with mild placental abruption may have no obvious symptoms before delivery, and only during postpartum examination of the placenta, clot pressure is found at the abruptio, which is easily ignored. The abdominal examination shows that the uterus is hard like a plate on palpation and there is pressure pain, especially at the placenta attachment area. The examination of placenta abruptio caused by a hard, plate-like uterus: 1. Light: Mostly vaginal bleeding and mild abdominal pain, placenta abruptio usually does not exceed 1/3 of the placenta, mostly seen during labor. The main symptom is vaginal bleeding, the amount of bleeding is usually more, dark red, may be accompanied by mild abdominal pain or abdominal pain is not obvious, anemia signs are not significant. If the bleeding occurs during labor, the labor progresses more rapidly. Abdominal examination: soft uterus, intermittent contractions, uterine size in accordance with the number of weeks of gestation, clear fetal position, normal fetal heart rate, if there is a lot of bleeding, the fetal heart rate may change, pressure pain is not obvious or only mild local (placenta abruptio) pressure pain. After postpartum examination of the placenta, clots and pressure marks can be seen on the maternal surface of the placenta. Sometimes the symptoms and signs are not obvious, and the placenta abruptio is only found when there are clots and pressure marks on the maternal surface of the placenta during the postpartum examination. 2.Heavy: mainly internal bleeding and mixed bleeding, with placental abruption surface more than 1/3 of the placenta and large post-placental hematoma, mostly seen in severe hyperemesis. The main symptoms are sudden onset of persistent abdominal pain and/or lumbago and back pain, the degree of which varies according to the size of the abruptive surface and the amount of blood accumulated behind the placenta, the more blood accumulated the more intense the pain. In severe cases, nausea, vomiting, pale face, sweating, weak pulse and decreased blood pressure may occur. There may be no vaginal bleeding or only a small amount of vaginal bleeding, and the degree of anemia does not correspond to the amount of external bleeding. Abdominal examination: The uterus is hard like a plate on palpation and there is pressure pain, especially at the placenta. If the placenta is attached to the posterior wall of the uterus, the uterine tenderness is not obvious. The uterus is larger than the number of weeks of gestation, and with the increasing size of the post-placental hematoma, the uterine fundus rises and the pressure pain becomes more pronounced. Occasionally, contractions are seen and the uterus is in a state of hypertension and does not relax well during intervals, so the fetal position is not clearly palpable. If the placental detachment surface exceeds 1/2 or more of the placenta, the fetus mostly dies due to severe hypoxia, so the fetal heartbeat of heavy patients has mostly disappeared.