Single-Balloon Compared With Double-Balloon Catheters for Induction of Labor: A Randomized Controlled Trial

Labor induction in nulliparous women with an unfavorable cervix: double balloon catheter versus dinoprostone

OBJECTIVE

We sought to compare the efficacy of the double-balloon catheter and dinoprostone for induction of labor among nulliparous women with an unfavorable cervix.

STUDY DESIGN

Nulliparous women with a Bishop score <6 were randomized to receive a 10-mg intra-vaginal dinoprostone insert or a double-balloon catheter. Primary outcome was time to delivery. Statistical analyses were performed by intention to treat using the chi-square, Fisher's exact, and Student's t-test, as appropriate.

RESULTS

The mean induction-to-delivery time was shorter in the double-balloon group as compared to the dinoprostone group (17.9±5.8 vs. 26.3±9.7 h) as was the time from induction to vaginal delivery (19.13±5 vs. 24.45±8.7 h, respectively). More women in the catheter group were delivered within 24 h compared to the dinoprostone group (87.1% vs. 47.4%). Approximately 50% of women in both groups delivered by cesarean section.

CONCLUSION

Induction of labor with the double-balloon catheter in nulliparous women with an unfavorable cervix is associated with a shorter time to delivery compared to dinoprostone.

Making cervical ripening EASI: a prospective controlled comparison of single versus double balloon catheters

OBJECTIVE

To compare the efficacy of two mechanical devices for cervical ripening: double versus single balloon catheters, both with extra-amniotic saline infusion (EASI).

METHODS

Women at term with a singleton pregnancy presenting for labor induction were assigned to receive the double balloon catheter (with EASI) or the single balloon catheter (with EASI). Outcomes included time from device insertion to delivery, rates of successful vaginal delivery and occurrence of adverse events.

RESULTS

One hundred and eighty-six women completed the study. Ripening success was comparable between the double and single balloon arms (96.4% versus 92.7%, p = 0.55, respectively). Balloon insertion to delivery interval was significantly shorter, and cesarean section rate was significantly lower in the double balloon arm compared with the single balloon arm (14.3 versus 15.8 h, p = 0.04 and 8.3% versus 20%, p = 0.05, respectively). There were no significant differences in maternal characteristics, satisfaction or adverse outcomes.

CONCLUSIONS

This study is the first documented assessment of the double balloon catheter combined with EASI. Our findings suggest that the double balloon catheter results in reduced time to delivery and higher vaginal delivery rates, compared with the single balloon catheter with EASI, without compromising maternal or fetal safety.

Foley catheter or prostaglandin E2 inserts for induction of labour at term: an open-label randomized controlled trial (PROBAAT-P trial) and systematic review of literature

OBJECTIVE

To assess the safety and effectiveness of a transcervical Foley catheter compared to vaginal prostaglandin E2 inserts for term induction of labour.

STUDY DESIGN

We conducted an open-label randomized controlled trial in five hospitals in the Netherlands. Women with a singleton term pregnancy in cephalic presentation, intact membranes, unfavourable cervix, and no prior caesarean section were enrolled. Participants were randomly allocated by a web-based randomization system to induction of labour with a 30 ml Foley catheter or 10mg slow-release vaginal prostaglandin E2 inserts in a 1:1 ratio. Due to the nature of the intervention this study was not blinded. The primary outcome was the caesarean section rate. Secondary outcomes were maternal and neonatal morbidity and time from intervention to birth. Additionally, we carried out a systematic review and meta-analysis of similar studies.

RESULTS

We analyzed 226 women: 107 received a Foley catheter and 119 inserts. Caesarean section rates were comparable (20% versus 22%, RR 0.90, 95% CI 0.54-1.50). Secondary outcomes showed no differences. We observed no serious maternal or neonatal morbidity. Meta-analysis showed comparable caesarean section rates, but significantly fewer cases of hyperstimulation during the ripening phase when a Foley catheter was used.

CONCLUSIONS

We found, in this relatively small study, no differences in effectiveness and safety of induction of labour with a Foley catheter and 10mg slow release vaginal prostaglandin E2 inserts. Meta-analysis confirmed a comparable caesarean section rate, and showed fewer cases of hyperstimulation when a Foley catheter was used.

Current methods of labor induction

In 2009, approximately 23% of all pregnant women in the United States underwent induction of labor, which is more than double the incidence of 9.5% in 1990. The ultimate goal of labor induction is to achieve vaginal delivery by stimulating uterine contractions before the spontaneous onset of labor. Labor induction is clearly indicated when the benefits outweigh the maternal and fetal risks of continued gestation, as well as potential risks associated with the procedure. Many women undergoing labor induction require cervical ripening--a method to facilitate softening, thinning, and dilation of an unfavorable cervix--because it reduces the time to delivery and incidence of failed induction. This article summarizes currently available methods for labor induction and cervical ripening, advantages and disadvantages of various methods, and the safety and effectiveness of each method based on well-conducted clinical trials.

A randomized trial of preinduction cervical ripening: dinoprostone vaginal insert versus double-balloon catheter

OBJECTIVE

We sought to compare the efficacy of a double-balloon transcervical catheter to that of a prostaglandin (PG) vaginal insert among women undergoing labor induction.

STUDY DESIGN

In all, 210 women with a Bishop score ≤6 were assigned randomly to cervical ripening with either a double-balloon device or a PGE2 sustained-release vaginal insert. Primary outcome was vaginal delivery within 24 hours.

RESULTS

The proportion of women who achieved vaginal delivery in 24 hours was higher in the double-balloon group than in the PGE2 group (68.6% vs 49.5%; odds ratio, 2.22; 95% confidence interval, 1.26-3.91). There was no difference in cesarean delivery rates (23.8% vs 26.2%; odds ratio, 0.88; 95% confidence interval, 0.47-1.65). Oxytocin and epidural analgesia were administered more frequently when a double-balloon device was used. Uterine tachysystole or hypertonus occurred more frequently in the PGE2 arm (9.7% vs 0%, P = .0007).

CONCLUSION

The use of a double-balloon catheter for cervical ripening is associated with a higher rate of vaginal birth within 24 hours compared with a PGE2 vaginal insert.

Mechanical methods for induction of labour

BACKGROUND

Mechanical methods were the first methods developed to ripen the cervix and induce labour. During recent decades they have been substituted by pharmacological methods. Potential advantages of mechanical methods, compared with pharmacological methods, may include simplicity of preservation, lower cost and reduction of the side effects.

OBJECTIVES

To determine the effects of mechanical methods for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment, prostaglandins (vaginal and intracervical prostaglandin E2 (PGE2), misoprostol) and oxytocin.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and bibliographies of relevant papers. We updated this search on 16 January 2012 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

Clinical trials comparing mechanical methods used for third trimester cervical ripening or labour induction with methods listed above it on a predefined list of methods of labour. A comparison with amniotomy will be added, should this comparison be made in future trials.Different types of intervention have been considered as mechanical methods: (1) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (2) the introduction of a catheter through the cervix into the extra-amniotic space, with or without traction; (3) use of a catheter to inject fluidsin the extra-amniotic spaceIn addition, we made other comparisons: (1) specific mechanical methods (balloon catheter and laminaria tents) compared with any prostaglandins or with oxytocin; (2) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data.

MAIN RESULTS

For this update we have included a further 27 studies. The review includes 71 randomised controlled trials (total of 9722 women), ranging from 39 to 588 women per study. Most studies reported on caesarean section, all other outcomes are based on substantially fewer women. Four additional studies are ongoing.Mechanical methods versus no treatment: one study (48 woman) reported on women who did not achieve vaginal delivery within 24 hours (risk ratio (RR) 0.90; 95% confidence interval (CI) 0.64 to 1.26). The risk of caesarean section was similar between groups (six studies; 416 women, RR 1.00; 95% CI 0.76 to 1.30). There were no cases of severe neonatal and maternal morbidity.Mechanical methods versus vaginal PGE2 (17 studies;1894 woman): The proportion of women who did not achieve vaginal delivery within 24 hours was not significantly different (three studies; 586 women RR 1.72; 95% CI 0.90 to 3.27); however, for the subgroup of multiparous women the risk of not achieving delivery within 24 hours was higher (one study; 147 women RR 4.38, 95% CI 1.74 to 10.98), with no increase in caesarean sections (RR 1.19, 95% CI 0.62-2.29). Compared with intracervical PGE2 (14 studies;1784 women and misoprostol there was no significant difference in the proportion of women not achieving vaginal delivery within 24 hours.Mechanical methods reduced the risk of hyperstimulation with fetal heart rate changes when compared with vaginal prostaglandins: vaginal PGE2 (eight studies; 1203 women, RR 0.16; 95% CI 0.06 to 0.39) and misoprostol (3% versus 9%) (nine studies; 1615 women, RR 0.37; 95% CI 0.25 to 0.54). Risk of caesarean section between mechanical methods and prostaglandins was comparable. Serious neonatal and maternal morbidity were infrequently reported and did not differ between the groups.Mechanical methods compared with induction with oxytocin (reduced the risk of caesarean section (five studies; 398 women, RR 0.62; 95% CI 0.42 to 0.90). The likelihood of vaginal delivery within 24 hours was not reported. Hyperstimulation with fetal heart rate changes was reported in one study (200 participants), and did not differ. There were no reported cases of severe maternal or neonatal morbidity.

AUTHORS' CONCLUSIONS

Induction of labour using mechanical methods results in similar caesarean section rates as prostaglandins, for a lower risk of hyperstimulation. Mechanical methods do not increase the overall number of women not delivered within 24 hours, however the proportion of multiparous women who did not achieve vaginal delivery within 24 hours was higher when compared with vaginal PGE2. Compared with oxytocin, mechanical methods reduce the risk of caesarean section.