Postpartum Hemorrhage Resulting From Uterine Atony After Vaginal Delivery

OBJECTIVE: To identify factors associated with severity of postpartum hemorrhage among characteristics of women and their delivery, the components of initial postpartum hemorrhage management, and the organizational characteristics of maternity units. METHODS: This population-based cohort study included women with postpartum hemorrhage due to uterine atony after vaginal delivery in 106 French hospitals between December 2004 and November 2006 (N=4,550). Severe postpartum hemorrhage was defined by a peripartum change in hemoglobin of 4 g/dL or more. A multivariable logistic model was used to identify factors independently associated with postpartum hemorrhage severity. RESULTS: Severe postpartum hemorrhage occurred in 952 women (20.9%). In women with postpartum hemorrhage, factors independently associated with severity were: primiparity; previous postpartum hemorrhage; previous cesarean delivery; cervical ripening; prolonged labor; and episiotomy; and delay in initial care for postpartum hemorrhage. Also associated with severity was 1) administration of oxytocin more than 10 minutes after postpartum hemorrhage diagnosis: 10-20 minutes after, proportion with severe postpartum hemorrhage 24.6% compared with 20.5%, adjusted OR 1.38, 95% CI 1.03-1.85; more than 20 minutes after, 31.8% compared with 20.5%, adjusted OR 1.86, CI 1.45-2.38; 2) manual examination of the uterine cavity more than 20 minutes after (proportion with severe postpartum hemorrhage 28.2% versus 20.7%, adjusted OR 1.83, 95% CI 1.42-2.35); 3) call for additional assistance more than 10 minutes after (proportion with severe postpartum hemorrhage 29.8% versus 24.8%, adjusted OR 1.61, 95% CI 1.23-2.12 for an obstetrician, and 35.1% compared with 29.9%, adjusted OR 1.51, 95% CI 1.14-2.00 for an anesthesiologist); 4) and delivery in a public non-university hospital. Epidural analgesia was found to be a protective factor against severe blood loss in women with postpartum hemorrhage. CONCLUSION: Aspects of labor, delivery, and their management; delay in initial care; and place of delivery are independent risk factors for severe blood loss in women with postpartum hemorrhage caused by atony. LEVEL OF EVIDENCE: II.