患者24岁，初孕36周。1977年3月3日晨开始出现无诱因，无痛性阴道流血，出血量时多时少，在个体诊所肌注止血敏、维生素K12日，效果不佳，且阴道流血量增多，于1997年3月5日急诊入院。既往健康。体检：无异常体征。宫底剑突下4横指，右枕前位．船头浮，胎心140／min，阴道有大 Patients 24 years old, 36 weeks of first trimester. On the morning of March 3, 1977, there were no inducing and painless vaginal bleeding in the early morning of March 3, 1977, and the amount of bleeding was less than usual. In the individual clinics, intramuscular hemostasis and vitamin K12 were not effective and vaginal bleeding increased. On the 5th of the emergency room admission. Past health. Physical examination: no abnormal signs. Palace under the sword sudden horizontal 4 fingers, right anterior pillow. Bow float, fetal heart 140 / min, the vagina is large