The associated factors of postpartum haemorrhage in placenta previa were history of multiple abortions (more than twice) , previous cesa rean section, elder age, type of placenta previa, no prenatal check, prenatal bleeding and other complications.

• ( 2 )与前置胎盘产后出血量有关的因素有高龄产妇、2次以上流产史、剖宫产史、前壁的前置胎盘、完全性前置胎盘、有产前出血史、无产前检查、存在妊娠合并症或并发症 ;