Effect of induction on maternal and neonatal outcomes of vaginal birth after cesarean

Abstract

Objective: To investigate the effect of induction on maternal and neonatal outcomes of vaginal birth after cesarean section (VBAC). Methods: Retrospective cohort study. A total of 452 pregnant women who underwent trail of labor after cesarean section (TOLAC) from January 2015 to March 2019 of Beijing Obstetrics and Gynecology Hospital, Capital Medical University were enrolled. According to the mode of the onset of labor, those 331 women who underwent VBAC were divided into spontaneous labor group (n=280) and induction group(n=51). According to induction methods, the pregnant women in the induction group was divided into the low-dose oxytocin subgroup (n=35) and other method subgroup (n=16, 9 cases with cervical ripening by balloon and 7 cases combined with oxytocin). The effect of induction on labor duration and maternal and neonatal outcome in VBAC were analyzed. Results: No maternal and neonatal death occurred. There were 23.0% (76/331) with forceps, 15.1% (50/331) of postpartum hemorrhage, and 24.5% (81/331) of fetal distress. The gravidity, birth weight and the gestational weeks of delivery in the induction group were significantly higher than those in the spontaneous onset group [2.0 (2.0-3.0) vs 2.0(1.0-2.0) times, 39.0(38.0-40.0) vs 38.0(37.0-39.0) weeks, (3 467±372) vs (3 168±538) g, Z=-3.548,-3.892,-3.813, all P<0.01]. The duration of the second stage of labor was significantly longer than that of the spontaneous onset group [43(26-60) vs 30(17-49) min, Z=-2.145,P<0.05], but the duration of the first stage, the total duration of labor, the rate of forceps, the incidence of postpartum hemorrhage, the rate of perineal incision and the incidence of fetal distress were not obvious different (all P>0.05). The duration of the first stage and total duration in oxytocin group were significantly shorter than those other method group [260(210-435) vs 325(250-490) min, 450(355-620) vs 523(370-668) min, Z=-2.001,-1.913, all P<0.05]. There were not significantly different in the duration of second stage, mode of delivery, perineal injury, the rate of postpartum hemorrhage, and fetal distress in the two groups (all P>0.05). Conclusion: Pregnant women who have undergone TOLAC after caesarean section can be induced after fully evaluation. Although induction prolongs the labor duration, it does not affect the maternal and neonatal complication rate.