This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Complication of 3rd Stage of Labour, Subject name: Gynaecology & Obstetrics
Most common cause of post-partum haemorrhage is : 
Select and explain. 
A. Uterine atony, B. Retained products, C. Trauma, D. Bleeding disorders.
A: Uterine atony
Answer: A: Uterine atony 
Explanation: Ans. is 'a' Uterine atony Causes of Post mortem hemorrhageAtonic uterus (80%)*Grand multipara *Overdistension of uterus*Malnutrition and anemia *APH*Prolonged labour*AnaesthesiaDelivery with aid of oxytocinPersistent uterine distensionMalformation of uterusUterine fibroid*Mismanaged 3n^ stage of labourConstriction ringPrecipitate labourTraumatic Q MixedD) Blood coagulopathy