Calculated blood loss in severe obstetric hemorrhage and its relation to body mass index

Objective To evaluate total calculated blood loss at the time of severe obstetric hemorrhage. Study Design This is a prospective observational study of women with obstetric hemorrhage. Women who received a blood transfusion for hypovolemia and those in which a body mass index (BMI) could be calculated were included. Total blood volume lost was calculated. Blood loss was analyzed in relation to maternal size as reflected in the BMI. Results Fourteen hundred forty-three women meeting inclusion criteria delivered at our hospital between March 2002 and June 2006. The median calculated volume of blood lost was 3529 mL, and 93% of women sustained losses 3000 mL. The blood loss sufficient to provoke signs and symptoms of hypovolemia was proportional to the woman's BMI. Conclusion Women who develop hypovolemia during childbirth have suffered very large losses of blood, and infusion of blood products is required to restore circulation and prevent further morbidity.