Comparison of intracervical Foley catheter used alone or combined with a single dose of dinoprostone gel for cervical ripening: a randomised study.

Prostaglandins and intracervical catheters are similarly effective for cervical ripening and for an induction of labour (IOL). Studies comparing the combined use with either method alone have administered repetitive doses of prostaglandins vaginally, which may increase the risk of tachysystole and chorioamnionitis. These disadvantages may be offset by co-administering a single dose of prostaglandin. Women (n=110) planned for IOL, 37weeks of gestation and with a Bishop Score of 6 were randomised into two groups: intracervical Foley catheter alone or combined with dinoprostone gel (0.5mg) for 12hours followed by oxytocin. The primary outcome was the IDI and the others were: change in Bishop Score, caesarean section (CS) requirement, any complications and neonatal outcome. The baseline Bishop was 4 in all and >80% were nulliparous. The post-ripening Bishop was significantly higher (6.67 vs. 5.98; p=.045) and the IDI was significantly lower in the combined group (16hours and 16minutes vs. 20hours 44minutes, p=.002). The CS rate was similar (29.1 vs. 25.5%; p=.669). No woman had hyperstimulation or chorioamnionitis and the neonatal outcomes were similar. Thus, co-administering one dose of an intracervical PGE2 gel with Foley was superior to Foley alone for cervical ripening and IOL.Impact statementWhat is already known on this subject? Prostaglandins and intracervical balloon catheters used individually are similarly effective for ripening an unfavourable cervix prior to the induction of labour (IOL). A few studies which have compared their found it to result in a shorter cervical ripening time and induction delivery interval (IDI) as compared to prostaglandins alone, though chorioamnionitis was a concern. When compared to balloon catheter used alone, combined use was either similarly or more effective. The studies comparing combined use with either method used alone have administered repetitive doses of prostaglandins vaginally, which may increase the risk of tachysystole, and possibly of chorioamnionitis. Co-administering a single dose of prostaglandin with a balloon catheter may offset these disadvantages.What do the results of this study add? A combined method for cervical ripening using a single dose of intracervical dinoprostone gel (PGE2, 0.5mg) coadministered with an intracervical Foley catheter was superior to Foley catheter alone. The combined method improved the Bishop score after 12hours and reduced the IDI significantly compared to the Foley catheter alone; while the caesarean rate and neonatal outcomes were similar. No woman had chorioamnionits or hyperstimulation.What are the implications of these findings for clinical practice and/or further research? The combined methods for cervical ripening should be compared to individual methods in more women, and the combinations may explore the use of other single use prostaglandins like the dinoprostone vaginal insert or misoprostol tablets.