To evaluate changes in maternal & neonatal morbidity for women attempting vaginal birth after cesarean (VBAC), following changes in clinical practice based upon ACOG's 2010 VBAC practice bulletin.METHODS:
Four-year retrospective cohort analysis around implementation of an academic hospital guideline in women who attempted VBAC at ≥24 weeks with a live, cephalic, singleton without a lethal anomaly and ≥1 prior cesarean. Maternal & neonatal outcomes pre- & post-guideline implementation were compared. Primary outcome was composite maternal morbidity (uterine rupture, uterine dehiscence, hysterectomy, transfusion, thromboembolism, operative/delivery injury, chorioamnionitis/endometritis, shoulder dystocia, maternal death).RESULTS:
VBAC was attempted by 450 women before & 781 women after guideline implementation. Post-guideline, there was a significant increase in the age, body mass index & length of labor in women attempting VBAC as well as the number of women with >1 cesarean, a comorbid medical condition & induced labor. On univariate analysis, composite maternal morbidity was significantly higher after the guideline (13.78% vs 18.82%, P=.02), possibly due to an increased rate of chorioamnionitis/endometritis. This association was no longer significant after control for potential confounders in multivariable analysis nor were there any differences in neonatal outcomes. VBAC success rates were unchanged (78.89% before vs 78.10% after, P=.75), however hospital VBAC rates increased after the guideline (26% vs 33%, P<.0001).CONCLUSION:
Adoption of VBAC practice changes proposed by ACOG can allow for an increase in the VBAC rate without a concomitant increase in maternal or neonatal morbidity.