 Introduction/Background Postpartum hemorrhage (PPH) is among the top three causes of maternal death in the United States and accounts for 27% of all maternal deaths worldwide [1,2]. PPH affects 1% to 5% of all deliveries and may be life-threatening. PPH in the first 24 hours after delivery is termed primary or early PPH, whereas after 24 hours to 6 weeks it is termed secondary, late, or delayed PPH. Although classically, PPH has referred to pregnancies delivered beyond 20 weeks of gestation, the definition may be expanded to include hemorrhage post terminations or early pregnancy loss [3]. PPH is defined as any hemorrhage associated with signs or symptoms of hypovolemia within 24 hours of delivery, regardless of the type of delivery [4]. Conservative measures such as uterine tamponade with either packing or balloon catheter and massage, uterotonic medications, and correction of coagulopathies are the first line of treatment. Once a specific diagnosis has been identified, tailored intervention such as curettage for RPOC, embolization for VUA, antibiotics for infection, evacuation of large bladder hematoma, or surgical repair for uterine rupture can be performed. Uterine artery embolization, surgical ligation of uterine/internal iliac arteries, or hysterectomy may be necessary if these measures fail. Of special note is the evolving diagnosis and management of VUA. Myometrial VUA are believed to represent subinvolution of the placental bed, may be associated with RPOC, and will resolve either with removal of RPOC or expectant management in most patients. Timmerman et al [7] has reported an increased risk of significant PPH in those areas of intense myometrial vascularity with peak systolic velocity >83 cm/s. A subsequent report by the same group indicated surgical removal of RPOC would also result in almost immediate resolution of these areas of intense myometrial vascularity [8,9].
Postpartum Hemorrhage.  Introduction/Background Postpartum hemorrhage (PPH) is among the top three causes of maternal death in the United States and accounts for 27% of all maternal deaths worldwide [1,2]. PPH affects 1% to 5% of all deliveries and may be life-threatening. PPH in the first 24 hours after delivery is termed primary or early PPH, whereas after 24 hours to 6 weeks it is termed secondary, late, or delayed PPH. Although classically, PPH has referred to pregnancies delivered beyond 20 weeks of gestation, the definition may be expanded to include hemorrhage post terminations or early pregnancy loss [3]. PPH is defined as any hemorrhage associated with signs or symptoms of hypovolemia within 24 hours of delivery, regardless of the type of delivery [4]. Conservative measures such as uterine tamponade with either packing or balloon catheter and massage, uterotonic medications, and correction of coagulopathies are the first line of treatment. Once a specific diagnosis has been identified, tailored intervention such as curettage for RPOC, embolization for VUA, antibiotics for infection, evacuation of large bladder hematoma, or surgical repair for uterine rupture can be performed. Uterine artery embolization, surgical ligation of uterine/internal iliac arteries, or hysterectomy may be necessary if these measures fail. Of special note is the evolving diagnosis and management of VUA. Myometrial VUA are believed to represent subinvolution of the placental bed, may be associated with RPOC, and will resolve either with removal of RPOC or expectant management in most patients. Timmerman et al [7] has reported an increased risk of significant PPH in those areas of intense myometrial vascularity with peak systolic velocity >83 cm/s. A subsequent report by the same group indicated surgical removal of RPOC would also result in almost immediate resolution of these areas of intense myometrial vascularity [8,9].