In the United Kingdom, half of maternal deaths from hemorrhage are due to postpartum events(superscript [1]) Uterine atony, degrees of retained placenta and genital tract lacerations account for most cases of postpartum hemorrhage.

• 造成产后大出血的原因包括产道裂伤、胎盘滞留、子宫收缩无力及孕妇本身凝血功能异常。