Postpartum hemorrhage is defined as blood loss of ≥500 mL for vaginal delivery or 1000 mL for abdominal (Caesarean) delivery after completion of the 3rd stage of labor.
Another proposed definition is a 10% fall in hematocrit value.
Since the clinical estimation of the amount of blood loss is typically inaccurate, the diagnosis of postpartum hemorrhage remains a subjective clinical assessment of the amount of blood loss that jeopardizes a woman's hemodynamic stability.
Postpartum hemorrhage may produce hemodynamic instability during the 1st 24 hours after delivery.
Immediate administration of the antifibrinolytic tranexamic acid increased the likelihood of survival in patients with acute severe haemorrhage, with efficacy reducing with every 15-minute delay in treatment, according to a large study.
Women given tranexamic acid within three hours of giving birth appear to have a reduced risk of death due to postpartum haemorrhage (PPH), according to findings of the large, multinational WOMAN* trial.