Postpartum hemorrhage after vaginal birth: an analysis of risk factors

To determine, in a single tertiary obstetric hospital, the incidence of and risk factors for postpartum hemorrhage (PPH) after a vaginal birth.

PPH was defined as measured blood loss greater than 1,000 mL and/or need for a transfusion.

Over a 4-year period, 13,868 of 19,476 women delivered vaginally, with a PPH rate of 5.15%. Identified risk factors for PPH were Asian race, maternal blood disorders, prior PPH, history of retained placenta, multiple pregnancy, antepartum hemorrhage, genital tract lacerations, macrosomia (>4 kg), and induction of labor, as well as chorioamnionitis, intrapartum hemorrhage, still birth, compound fetal presentation, epidural anesthesia, prolonged first/second stage of labor, and forceps delivery after a failed vacuum.

Identification of risk factors for PPH after a vaginal delivery may afford prophylactic treatment of such women with reduction of morbidity.