Influence of Different Delivery Modes on Postpartum Hemorrhage in Low-risk Women

  Objective  To compare the blood loss between vaginal delivery and cesarean section in women at low-risk for postpartum hemorrhage, and to explore the risk factors of postpartum hemorrhage.

  Method  The clinical data of nulliparous women who delivered in Peking Union Medical College Hospital from November 2008 to October 2009 were retrospectively analyzed. Women at high risk for postpartum hemorrhage (including placenta previa, placental abruption, and severe preeclampsia) were excluded. Pre-and post-delivery hematocrit (HCT) and hemoglobin (HGB) were recorded and compared between the vaginal delivery group and cesarean section group. The risk factors associated with postpartum hemorrhage were analyzed.

  Result  After the delivery, the median decrease of HGB and HCT was-3 g/L (-10 g/L--3 g/L) and-1% (-3.1%--1.1%), respectively, in the elective cesarean section group, and was-8 g/L (-17 g/L-0 g/L) and-2.8% (-5.4%-0.1%) in the vaginal delivery group (both P < 0.05). The median decrease of HGB and HCT was-2.0 g/L (-12.7 g/L -4 g/L) and-1.0% (-3.98% -1.4%) in the no-episiotomy vaginal delivery group, which was not significantly different from that in the cesarean section group. Forceps, episiotomy, and postpartum curettage were risk factors for postpartum hemorrhage in vaginal delivery group.

  Conclusions  For pregnant women at low risk for postpartum hemorrhage, blood loss during Cesarean section is larger than in vaginal delivery. Forceps, episiotomy, and postpartum curettage are risk factors for postpartum hemorrhage in vaginal delivery group.