Predictors for outcome of induction of labour with double balloon catheter as second-line method after dinoprostone

Abstract

Objectives: To determine the predictors for outcome of induction of labour (IOL) with double balloon catheter (DBC) as the second-line method after dinoprostone.
Methods: Medical records of patients who underwent IOL with DBC as the second-line method after dinoprostone between October 2016 and December 2019 at Pamela Youde Nethersole Eastern Hospital in Hong Kong were retrospectively reviewed. Inclusion criteria were singleton pregnancy, vertex presentation, gestational age of ≥36 weeks, unfavourable cervix (Bishop score <6) after initial priming by dinoprostone, intact membranes, and no contraindication for vaginal delivery. The primary outcomes were the success and failure rates of IOL, which were defined as the rates of vaginal delivery and caesarean delivery, respectively.
Results: 88 patients were included for analysis. The most common indications for IOL were gestational diabetes (23.86%) and past term pregnancy (19.32%). 79 (91.86%) patients had successful cervical ripening after DBC insertion, with a median improvement in Bishop score of 3. However, only 32 (36.36%) patients achieved vaginal birth, whereas 56 patients had caesarean birth. The most common indication for caesarean birth was failed IOL (40.91%). An occiput-anterior position of the fetal head at delivery was predictive of a vaginal birth/successful IOL
(odds ratio=0.211, p=0.036), whereas a heavier birth weight was a risk factor for a caesarean birth/failed IOL (odds ratio=1.002, p=0.027).
Conclusion: The success rate of IOL with DBC as a second-line method was only 36.36%. The Bishop score before DBC insertion was not predictive of a successful IOL. Earlier consideration of caesarean section is suggested in patients with unsatisfactory response to dinoprostone as well as non-occiput-anterior position of the fetal head and heavier fetal weight.