Induction of labor at second delivery subsequent to a primary cesarean: is stage of labor at previous cesarean a factor?

Parturients with a history of a cesarean delivery (CD) in the first delivery (P1), undergoing induction of labor (IOL) in the subsequent delivery (P2) are at increased risk for obstetric complications. The primary aim was to study if "the stage of labor" at previous cesarean (elective/latent/first/second) is associated with a successful IOL. The secondary aim was to search for other obstetric characteristics associated with a successful IOL. A retrospective longitudinal follow-up study in a large tertiary medical center. All parturients at term who underwent IOL at P2 with a singleton fetus in cephalic presentation, with a prior CD, between the years 2006 and 2014 were included. A univariate analysis was performed including the stage of labor at previous cesarean, birth weight of newborn at P1 and P2, gestational week of delivery at P2, time of interpregnancy interval, indication and mode of IOL, epidural analgesia and augmentation of labor at P2. Significant factors were incorporated in a multivariate logistic regression model. During the study period, 150 parturients underwent IOL (P2) subsequent to a previous CD (P1). VBAC was achieved in 78 (52%). We found no association between the stages of labor in which the previous CD was performed to a successful IOL. Applying the multivariate logistic regression revealed that augmentation of labor with oxytocin, OR 4.17, [1.73-10.05], epidural analgesia OR 3.30 [1.12-9.73] and birth weight (P2) < 4000 g, OR 5.88, [1.11-33.33] were associated with a successful IOL. The stage of labor at previous CD should not be incorporated among the variables found to be associated with a successful IOL. As a result of our findings, clinician's will be able to adjust a personalized consult prior to initiating IOL.