Commonest cause of the Postpartum haemorrhage is

(Atonic uterus): Ref: 411-DPost partum haemorrhage the amount of blood loss in excess of 500 ml following birth of the babyCAUSES1. Atonic uterus: (80%) commonest cause of PPHGrand multipara, overdistension of the uterus, Malnutrition and anaemia, APH, prolong labour, Anaesthesia,Initiation or augmentation of delivery by oxytocin, Persistent uterine distensionMalformation of the uterus, uterine fibroids, Mismanaged third stage labour, constriction ring, Precipitate labour,2. Traumatic (20%), similarly blood loss in C.S. amounting to 800 - 1000 ml is most often ignored, episiotomy and lacerations3. Combination of atonic and traumatic causes4. Blood coagulation disorders, acquired or congenital: may be due to diminished procagulants (washout phenomenon) or increased fibrinolytic activity.The conditions where such disorders may occur are abruptioplacentae, jaundice in pregnancy, thrombocytopenia purpura, HELLP syndrome or in IVD