The MFMU cesarean registry: trial of labor after prior cesarean delivery: maternal and perinatal outcome


      To evaluate whether trial of labor (TOL) is associated with increased maternal or perinatal risk in women with a prior cesarean delivery (CD).

      Study design

      A prospective four-year (1999-2002) observational study at 19 academic centers of all women with singleton gestation and prior CD. All charts were reviewed by trained research nurses. Women attempting vaginal birth after cesarean (VBAC) were compared to women with elective repeat cesarean delivery (ERCD) without labor and no other indication for CD.


      Of 45,981 women with a prior CD, 15,800 underwent ERCD and 17,931 attempted VBAC. 12,250 women had other maternal or fetal indications for a repeat CD. The TOL rate was 39% and the VBAC success rate was 73%. Symptomatic uterine rupture occurred in 140 (0.78%) of TOL cases. Maternal complications (endometritis, transfusion) as well as the frequency of term infants with hypoxic ischemic encephalopathy (HIE) were increased in TOL versus ERCD (see table).


      When compared to elective repeat cesarean delivery, women attempting VBAC are at increased risk for maternal morbidity (uterine rupture, endometritis, transfusion) and newborn HIE. Trial of labor remains an option as the absolute risk for these complications is small.
      Tabled 1Maternal and Perinatal Outcome
      TOL N(%)ERCD N(%)RR (95% CI)P
      Uterine rupture140/17929 (0.78)0/15793 (0.0)<0.0001
      Hysterectomy41/17929 (0.23)47/15793 (0.30)0.77 (0.51-1.17)0.2158
      DVT/PE7/17898 (0.04)10/15773 (0.06)0.62 (0.23-1.62)0.3222
      Transfusion307/17930 (1.7)158/15794 (1.0)1.71 (1.41-2.07)<0.0001
      Endometritis518/17930 (2.9)284/15793 (1.8)1.61 (1.39-1.85)<0.0001
      Maternal death3/17929 (0.02)7/15793 (0.04)0.38 (0.10-1.46)0.2055
      Term intrapartum stillbirth7/15336 (0.05)3/15014 (0.02)2.28 (0.59-8.83)0.3439
      Term neonatal death12/15293 (0.08)6/14997 (0.04)1.96 (0.74-5.22)0.1697
      Term HIE14/15288 (0.09)1/14993 (0.01)13.73 (1.81-104.40)<0.001