796: Induction decreases success rates in vaginal birth after cesarean: Does indication matter?

Abstract

Labor induction occurs in over 20% of pregnancies in the United States. There is evidence that induction reduces the chances of successful VBAC. What is unknown however is whether the induction indication has a specific influence on success. We sought to evaluate the association between specific induction indication on TOLAC success. This was a retrospective cohort study of all patients undergoing TOLAC at a single academic tertiary care center between January 2011 and May 2018. Data were collected via individual chart review and analyzed by indication for induction. Comparison groups included elective, post-dates (≥41 weeks), fetal indication (non- reassuring testing, growth restriction, or oligohydramnios), maternal indication (hypertension or diabetes mellitus), and other indication. The primary outcome was VBAC success. Secondary outcomes included maternal composite morbidity and mortality (uterine rupture, hemorrhage, transfusion, ICU admission, cesarean hysterectomy, or death) and neonatal composite morbidity and mortality (5 minute APGAR < 7, arterial cord pH < 7, NICU admission, hypoxic ischemic encephalopathy, and death). Of the 1397 patients studied, 520 underwent labor induction. There was a significant difference in BMI and black race between induction indications; otherwise, there were no differences in demographic characteristics between the groups. VBAC success rate ranged from 60.0 - 70.1%, p=.062. There were no significant differences in the rates of VBAC success between groups (p=0.602). Maternal and neonatal composite morbidity and mortality were not significantly different amongst the groups. We did not observe any significant associations between induction indication and VBAC success in our cohort.View Large Image Figure ViewerDownload Hi-res image Download (PPT)