产后24 h出血超过500 ml称为产后出血,是孕产妇死亡的首位原因。根据2005年WHO的统计,平均每分钟就有一位孕产妇死亡[1]。产后出血的四大原因包括宫缩乏力、胎盘因素、软产道裂伤及凝血功能障碍。而最近几年很多新因素或以往未被重视的因素导致产后出血的发生,已成为产后出血不容忽视的一个重要的原因。下面笔者就这些新因素的产生原因及防治措施,综述如下。 24 h postpartum bleeding more than 500 ml called postpartum hemorrhage, maternal mortality is the first reason. According to 2005 WHO statistics, there is an average of one maternal death every minute [1]. Four main causes of postpartum hemorrhage include uterine inertia, placental factors, soft birth canal laceration and coagulation disorders. In recent years, many new factors or factors that have not been valued in the past lead to postpartum hemorrhage, has become an important reason for postpartum hemorrhage can not be ignored. The following author on the causes of these new factors and prevention measures, summarized as follows.