[Risk factors of postpartum hemorrhage during labor and clinical and pharmacological prevention]

Abstract

Prevention of postpartum hemorrhage (PPH) is a major concern in regards to its impact on maternal morbidity and mortality. While established risk factors can be identified among risk factors of PPH during labor after multivariate analysis: prolonged labor, oxytocin stimulation of labor, cesarean section, instrumental delivery, genital lacerations and episiotomy, prolonged third stage of labor, retained placenta; other risk factors are still uncertain: induction of labor, hyperthermia or chorioamniotitis, analgesia or anesthesia, macrosomia, various cesarean section techniques. Isolated identified risk factors have a moderate incidence on PPH, but their cumulation in one patient is a potential high risk. Among active management schemes of third stage of labor for PPH prevention, the most efficient technique seems to be direct injection of oxytocin when the baby's shoulders are delivered, associated with controlled cord traction. If this technique is a must for high-risk patients for PPH, and seems efficient for every patient, a correctly performed procedure requires the presence of a competent professional in addition to the midwife or obstetrician in charge of delivery, and a permanent attention so the length of third stage of labor is shortened. The alternative use of prophylactic misoprostol in the third stage of labor is less effective than injectable uterotonics in reducing PPH, and is associated with more side effects (severe shivering, pyrexia, diarrhea). None of other described prophylactic methods have proved efficiency: early suckling, umbilical blood drainage, oxytocin umbilical vein injection, among others. A decrease in PPH prevalence should be obtained by particular attention on data from the early postpartum period, active diffusion of effective prophylactic techniques, and an appropriate choice in regards to each delivery unit organization.