Grouping parturients by parity, previous-cesarean, and mode of delivery (P-C-MoD classification) better identifies groups at risk for postpartum hemorrhage

Objective We aimed to create a clinical classification to better identify parturients at risk for postpartum hemorrhage (PPH). Method A retrospective cohort, including all women who delivered at a single tertiary care medical center, between 2006 and 2014. Parturients were grouped by parity and history of cesarean delivery (CD): primiparas, multipara, and multipara with previous CD. Each were further subgrouped by mode of delivery (spontaneous vaginal delivery [SVD], operative vaginal delivery [OVD], emergency or elective CD). In all, 12 subgroups, based on parity, previous cesarean, and mode of delivery, formed the P-C-MoD classification. PPH was defined as a decrease of ≥3 gram% hemoglobin from admission and/or transfusion of blood products. Univariate analysis followed by multivariate analysis was performed to assess risk for PPH, controlling for confounders. Results The crude rate of PPH among 126,693 parturients was 7%. The prevalence differed significantly among independent risk factors: primiparity, 14%; multiparity, 4%; OVD, 22%; and CD, 15%. The P-C-MoD classification, segregated better between parturients at risk for PPH. The prevalence of PPH was highest for primiparous undergoing OVD (27%) compared with multiparous with SVD (3%), odds ratio [OR] = 12.8 (95% confidence interval [CI],11.9-13.9). These finding were consistent in the multivariate analysis OR = 13.1 (95% CI,12.1-14.3). Conclusion Employing the P-C-MoD classification more readily identifies parturients at risk for PPH and is superior to estimations based on single risk factors.