Effect of a Collector Bag for Measurement of Postpartum Blood Loss After Vaginal Delivery: Cluster Randomised Trial in 13 European Countries

Abstract

Delay in the diagnosis and initial treatment of postpartum hemorrhage may occur as result of visual underestimation of blood loss. A number of studies have reported that visual estimates of postpartum blood loss are often inaccurate. To address this problem, the use of a collector bag has been proposed to provide an objective and more accurate measurement of blood loss than visual assessment. If effective, when excessive blood loss is observed, a more rapid response by a caregiver would be triggered. Currently, the bag is used routinely in many maternity wards in European countries despite lack of evidence for its efficacy. This cluster randomized controlled trial investigated the effectiveness of a transparent plastic collector bag in reducing the incidence of severe postpartum hemorrhage after vaginal delivery by providing an accurate measurement of postpartum blood loss. The trial was conducted at 78 maternity units in 13 European countries between 2006 and 2007. The participants—25,381 women who had a vaginal delivery—were randomized to systematic use of a collector bag (intervention group, n = 11,037) or to continued visual assessment of postpartum blood loss (control group, n = 14,344). The primary study outcome was the incidence of severe postpartum hemorrhage defined as a composite of all women who experienced one or more of the following: blood transfusion, intravenous plasma expansion, surgical procedure or arterial embolization, treatment with recombinant factor VII, or death. There was no statistical difference between the groups in the incidence of severe postpartum hemorrhage (intervention group: 1.71%, 189/11,037 vs. control group: 2.06%, 295/14, 344) using either individual level analysis or cluster level analysis. In individual level analysis (with data adjusted for maternal age, prophylactic uterotonics used in the third stage, mode of delivery, and birth weight), the adjusted odds ratio was 0.82, with a 95% confidence interval of 0.26 to 2.53, P = 0.7. In cluster level analysis, following adjustment for the baseline rate of severe postpartum hemorrhage, the adjusted weighted mean difference was 0.16%, with a 95% confidence interval of −0.69% to 1.02%, P = 0.7. These findings indicate that the systematic use of a collector bag after vaginal delivery does not reduce the rate of severe postpartum hemorrhage compared to visual estimation.