Results Uterine atony, placenta factor, obstetric trauma and coagulation defects are the main causes.The related factors include delivery way, labor stage factors and Psychological factors.

• 结果产后出血原因主要为子宫收缩乏力、胎盘因素、软产道损伤、凝血功能障碍等，影响产后出血的因素：分娩方式、产程胎盘因素、心理因素等。