Introduction: Oxytocin use in the management of TOLAC is controversial. Data assessing the relationship between oxytocin use and adverse outcomes is scant.
Methods: Chart review of 159 patients with one prior cesarean undergoing TOLAC divided into those who were: (1) induced with oxytocin (IND, n=44), (2) augmented with oxytocin (AUG, n=37) and (3) managed expectantly after presenting in labor (SPON, n=78). Following obtained: maternal baseline characteristics, amount administered and duration of oxytocin use if used, incidence of adverse outcomes. Chi-square and ANOVA were used for statistical analysis.
Results: Baseline characteristics between groups were similar. Two cases of uterine ruptures and one of hemorrhage occurred in the IND group. All three cases had an initial Bishop score less than 5. Average total amount of oxytocin administered and duration of oxytocin use in this subgroup were 4412 milliunits and 12.7 hours. Five patients underwent cervical ripening balloon placement followed by oxytocin for induction. In this subgroup, none experienced adverse outcomes and three of the five had a successful TOLAC. Average total amount of oxytocin administered and duration of oxytocin use were 1988 milliunits and 7.3 hours. One case of uterine dehiscence necessitating surgical intervention occurred in the SPON group. There were no complications in the AUG group. No significant differences were noted among the groups regarding other outcomes including cesarean delivery rate.
Conclusion: Induction of labor in the presence of an unfavorable cervix and prior cesarean is associated with adverse outcomes. Cervical ripening balloon has a role in achieving a successful TOLAC.