Abstract
Introduction: Mechanical cervical ripening methods are considered safer than prostaglandins. Many centers choose this method for pre-induction in pregnant patients with a previous cesarean section. Our objective was to compare efficacy and safety of two different mechanical ripening methods in prolonged pregnancies with a Bishop score ≤ 6 and a previous cesarean section. Methods: Non-randomized study during 6 years in which patients were divided in two cohorts: a first period of time (from November 2014 to November 2018) in which Foley catheter was used and a second period of time (from November 2018 to November 2020) in which double-balloon catheter (Cook® balloon) was the method employed. The same protocol was followed in both groups. Efficacy was defined by the achievement of active labor. Ripening success (changes in Bishop score and achievement of active labor), vaginal delivery rate and maternal and neonatal safety were recorded. Results: The double-balloon was placed in 43 patients and the Foley catheter was inserted in 129 patients. Cook catheter showed better Bishop score difference than Foley but with no statistically significance (3.09 vs 2.76, p=0.271). Active labor was achieved similarly in both groups (81.4% double-balloon vs 78.2% Foley catheter, p=0.726). Although there was a higher vaginal delivery rate in the double-balloon group (62.8%) compared with the Foley group (49.6%), the difference was not statistically significant (p=0.065). Time from catheter insertion to delivery was significantly shorter in the Foley group compared with Cook group (1704 vs 1903 minutes, p<0.05). Newborn weight, umbilical-cord pH, Apgar index and maternal complications were similar in both groups. Conclusion: Mechanical cervical ripening is a safe and effective method in pregnancies with a previous cesarean section. Double-balloon ripening associated higher vaginal delivery rate compared to Foley catheter, but without statistically significant differences.