Foley Balloon Catheter versus Oral Misoprostol for Induction of Labour after Prelabour Rupture of Membranes: A Retrospective Data Analysis

Abstract

Objectives: The Foley balloon catheter (FC) is a viable method for cervical ripening, but concerns about infection risk restrict its use in cases of prolonged prelabour rupture of membranes (PROM). This study aims to evaluate the efficacy and safety of the FC compared to oral misoprostol for cervical ripening after PROM. Study Design: A retrospective data-analysis of 128 pregnant women was conducted. Of these, 49 underwent cervical ripening with an FC and 79 with oral misoprostol. We included all women with a vital singleton pregnancy at 37 - 42 weeks of gestation who underwent cervical ripening after ≥ 24 hours of PROM in specific time frames in two Dutchsecondary care and teaching hospitals. The primary outcome was the incidence of intrapartum infection, a composite of maternal and neonatal infection. In addition, we evaluated the mode of delivery, duration of priming and priming-to-delivery interval. Secondary endpoints included uterine hyperstimulation, umbilical cord prolapse, birth weight, Apgar scores, length of admission to the neonatal low dependency unit, admission to the (neonatal) Intensive Care Unit (ICU) and mortality. Statistical analyses included bivariate and multivariate techniques. Results: Cervical ripening with FC, compared with oral misoprostol, showed a higher incidence of intrapartum infection, respectively 32.7% (n = 16) vs. 12.7% (n = 10) (p = 0.006). However, after adjusting for epidural anaesthesia and pregestational BMI, the association was no longer significant. No difference was found in mode of delivery and total priming-to-delivery interval (median 21.3 hours vs. 22.0, p = 0.897). Furthermore, FC, compared with oral misoprostol, showed a longer duration of cervical ripening and hence a shorter duration of active labour (p 0.001). Apart from the 1-min Apgar score, secondary maternal and neonatal outcomes did not differ between the groups. Conclusion: In women who require cervical ripening after prolonged PROM at term, the FC and oral misoprostol are similar in terms of efficacy and safety. Advantages associated with the FC are its safe application in women with a history of caesarean section, although we did not study these women, and an implied shorter duration of active labour. Our study adds to the limited available data on the use of the FC after the rupture of membranes and a large randomized controlled trial is needed to strengthen our findings.