PIP: The causes, risk factors, prevention, and clinical management of primary postpartum hemorrhage--a major cause of maternal mortality--are outlined in this report for clinicians. The major causes of primary postpartum hemorrhage include uterine atony, retained placenta, lower genital tract lacerations and hematomas, uterine rupture, consumptive coagulopathy, and acute inversion of the uterus. Detailed, step-by-step clinical management guidelines are presented for hemorrhage associated with each of these causes. Immediate and late complications of primary postpartum hemorrhage include hypovolemic shock, cerebral anoxia, renal failure, anemia, puerperal sepsis, and Sheehan's syndrome. The antepartum hemoglobin status and the rate of blood loss influence hemorrhage outcome.