Poster session V Clinical obstetrics, epidemiology, infectious disease, intrapartum fetal, operative obstetrics, medical-surgical-diseases-complications, obstetric quality and safety, public health/global health: Abstracts 687 - 836| Volume 208, ISSUE 1, SUPPLEMENT , S335-S336, January 01, 2013

799: Is vaginal delivery of a macrosomic infant after cesarean section really so dangerous?


      To determine whether women with a previous uterine scar and a macrosomic fetus have a higher risk of uterine rupture.

      Study Design

      A retrospective comparison of all singleton vaginal births after a cesarean delivery (VBAC) of a macrosomic infant (birthweight above 4000 gr) to those of normal weighing infants (<4000 gr) during the years 1988-2011 was conducted. Receiver operating characteristic (ROC) curves were used to determine an association between birthweight and the risk for uterine rupture.


      Of 31,310 VBAC that occurred during the study period, 5.3% (n=1644) were of macrosomic infants. No significant association was found between VBAC of a macrosomic infant and uterine rupture (Table). Likewise the rates of post partum hemorrhage, and peripartum hysterectomy were comparable between the groups. The ROC curve did not demonstrate a significant association between birthweight and the risk for uterine rupture among patients with a previous cesarean delivery (area under the curve: 0.46, 95% confidence interval [CI]: 0.40-0.52, P = 0.19).
      Tabled 1Selected pregnancy outcomes of patients with a macrosomic and a normal weight infant during VBAC
      Table thumbnail grr96


      A VBAC of a macrosomic infant is not associated with an increased risk for uterine rupture.