585: Trial of labor after cesarean (TOLAC) in women with Premature rapture of membranes

Abstract

Reducing the rate of cesarean section by increase in the rate of TOLAC is important to address since repeat cesarean section is associated with increased maternal morbidity and mortality. There is limited data regarding risks and benefits of TOLAC after premature rapture of membranes (PROM). We investigated the success rate of TOLAC after PROM between those receiving conservative management and those receiving labor induction. This was a retrospective cohort study conducted in a single tertiary care center between 01/2011-03/2017. All women with singleton pregnancy and a previous cesarean section who presented with PROM after 34 0/7 weeks of gestation and underwent TOLAC were included. To minimize labor induction, women were offered conservative management until spontaneous labor commenced. Labor induction was performed if spontaneous onset of labor did not take place within 48 hours or if there were signs of maternal or fetal distress. Operative complications were defined as: laceration of the uterus, bladder injury, urethral injury, bowel injury or hysterectomy. Postpartum complications were defined as: fever, endometritis, need for blood transfusion and wound complications. Outcomes and rate of successful vaginal delivery after induction of labor were compared to spontaneous onset of labor using univariable and multivariable analysis. Among 830 women who met the inclusion criteria, 723 (87.1%) had a spontaneous delivery and 107 (12.9%) had an induction of labor. The rate of successful TOLAC was similar between the groups (75.7% vs 81.6%, respectively, P=0.22). However, induction of labor was associated with an increased risk of uterine rupture (1.87% vs 0.96%, P <0.001), operative complications (30.76% vs 12.03%, P<0.001) and composite maternal postpartum complications (21.4% vs 12.1%, respectively, P= 0.014) compared to spontaneous vaginal delivery. There was no difference in neonatal outcome between the groups. In women attempting TOLAC who present with PROM and fail to progress spontaneously into active labor, Induction of labor is associated with high successful vaginal delivery rate. However, the risk for uterine rupture and operative and maternal complications is significantly increased compared to spontaneous delivery.