Mechanisms, Equipment, HazardsRisk Factors for Retained PlacentaCoviello, E.M.; Grantz, K.L.; Huang, C.C.; Kelly, T.E.; Landy, H.J.Author Information Department of Obstetrics and Gynecology, MedStar Washington Hospital Center, Washington, DC Obstetric Anesthesia Digest: December 2016 - Volume 36 - Issue 4 - p 202-203 doi: 10.1097/01.aoa.0000504730.26655.a7 Buy Metrics Abstract (Am J Obstet Gynecol. 2015;213:864.e1–e.11) According to the World Health Organization, in developing countries, postpartum hemorrhage is the primary cause of maternal mortality, responsible for 25% of maternal fatalities. About 2% to 3% of vaginal deliveries are complicated by postpartum hemorrhage for which the treatment includes manual or operative placental extraction and this often results in increased risks of hemorrhage, infection, and prolonged hospital stays. The objective of this study was to evaluate the risk factors for retained placenta (defined as >30 min between the delivery of the fetus and placenta). Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.