Subsequent Pregnancy Outcomes after Failed Vacuum-Assisted Delivery

OBJECTIVE: To examine trial of labor after cesarean delivery (TOLAC) success rates and its associated factors among women with a previous failed vacuum-assisted vaginal delivery. METHODS: We conducted a retrospective cohort study. The study group comprised all women with a prior failed vacuum-assisted vaginal delivery who subsequently delivered from 2008 to 2017 at a university hospital. RESULTS: Overall, 166 women with prior history of failed vacuum-assisted vaginal delivery delivered during the study period, with a median interdelivery interval of 28 (21-36) months. Of them, 53 (32%) had an elective repeat cesarean delivery, and 113 (68%) had a TOLAC. Although there were small statistical differences in the predelivery characteristics of the two groups, there were not clinically significant differences. Of the 113 women who underwent TOLAC in the subsequent pregnancy, the overall success rate was 67%. Neonatal 1- and 5-minute Apgar scores were lower among neonates born to women who experienced a failed TOLAC attempt compared with those who underwent successful TOLAC: 1-minute Apgar score less than 7 (6 [16%] vs 2 [3%], odds ratio [OR] 7.16, 95% CI 1.36-37.45, P=.01), 5-minute Apgar score less than 8 (3 [8%] vs 0 [0%], OR 15.5, 95% CI 1.78-308.7, P=.03). No events of obstetric anal sphincter injury, postpartum hemorrhage and uterine rupture were encountered among women who underwent TOLAC. CONCLUSION: Trial of labor after cesarean delivery in women with a previous failed vacuum-assisted vaginal delivery appears to be associated with an acceptable success rate. These data should improve patient counseling and provide reassurance for those who wish to deliver vaginally after a previous failed vacuum-assisted vaginal delivery.