Obstetric hemorrhage and blood utilization.

Patients on a busy obstetric service were prospectively evaluated to determine which ones required blood transfusion. During the period January-April 1990, 5,528 deliveries were performed. Fifty-five patients (0.99%) received blood transfusions during their pregnancy and puerperium. The most common conditions associated with transfusion were trauma due to instrumental delivery (16), uterine atony (15), placenta previa (12), retained products of conception (4), abruptio placentae (4) and coagulopathy secondary to the HELLP syndrome (1). Platelets, fresh frozen plasma, whole blood and cryoprecipitate were administered to 7, 6, 1 and 1 patients, respectively. The transfusion rates by procedure were emergency cesarean hysterectomy for bleeding placenta previa or atony, 7/7 (100%); vacuum extraction, 7/114 (6.1%); forceps delivery, 12/285 (4.2%); uncomplicated cesarean delivery, 10/704 (1.4%); and spontaneous vaginal birth, 19/4,425 (0.4%). The hemorrhage and subsequent need for a blood transfusion were not necessarily due to the procedure except in the case of trauma due to instrumental vaginal delivery. The rate of transfusion of red blood cells for patients undergoing vaginal instrumental delivery was significantly higher than the rate for those undergoing cesarean delivery (relative risk, 2.8; 95% confidence interval, 1.5-5.2). The need for transfusion can be anticipated on the basis of antepartum causes in only 23.7% of patients ultimately receiving blood products.