The quality control criteria for postpartum hemorrhage rate are based on the amount and rate of bleeding. Postpartum hemorrhage is defined as bleeding greater than or equal to 500 milliliters for vaginal deliveries and 1,000 milliliters for cesarean deliveries within 24 hours after delivery of the fetus. Postpartum hemorrhage of more than 1500 ml within 24 hours is called severe hemorrhage. The patient may have pre-shock manifestations such as a drop in blood pressure and increased heart rate. In the case of dangerous placenta previa, bleeding can be up to 200 ml in one minute and 1,000 ml in a few minutes, and hypovolemic shock may occur in a short period of time if blood transfusion and hemostasis are not provided in a timely manner. Severe postpartum hemorrhage that cannot be stopped by conservative measures such as contractions, continuous uterine massage or compression requires surgery, intervention, or even hysterectomy. Weak contractions, placental factors, soft birth tears and coagulation disorders are the main causes of postpartum hemorrhage. These causes can co-exist, interact or be causal to each other. If you have any other questions, it is advisable to consult a medical professional for guidance.