北京积水潭医院精品课件——产前出血

产前出血Р妊娠20周后,胎儿娩出前,阴道有明显出血为~。? 产前出血的原因? 前置胎盘? 胎盘早剥? 帆状胎盘血管前置破裂? 胎盘边缘血窦破裂? 宫颈息肉? 宫颈糜烂? 宫颈癌变? 静脉曲张等Р第一节前置胎盘?Placenta PraeviaР【定义】? 孕20周后,胎盘附着于子宫下段,胎盘边缘达到或覆盖子宫颈内口,其位置低于胎儿先露部者。? 发病率国内0.24~1.75%,国外0.3~0.9%。Р正常位置子宫胎盘胎儿的关系Р【病因】不清Р1.子宫体部内膜病变与损伤?2.胎盘面积过大或胎盘其他异常?3.受精卵发育迟缓?4.宫腔形态异常? 5 . 其他:缺氧导致胎盘代偿性增大Р【分类】取决于胎盘边缘与宫颈内口的关系Р中央型前置胎盘: the internal cervical os is pletely by placenta.?部分性前置胎盘: the internal os is partially covered by placenta.?边缘性前置胎盘: the edge of the placenta is at the margin of the internal os.?低置胎盘: the placenta is implanted in the lower uterine segment such that the placenta edge actually does not reach the internal os but is in close proximity to it. Р¤ 以处理前最后一次检查来决定其分类Р临床表现—出血Р妊娠晚期或临产时发生无诱因的、无痛性、反复的阴道流血是前置胎盘的主要症状Р 阴道出血发作的? 早晚、次数、出血量? 与前置胎盘的类型密切相关Р产后止血的机制Р子宫收缩Р内外交错的子宫肌纤维Р生理性结扎作用