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

Interval between balloon removal and oxytocin administration in cervical ripening with double-balloon in singleton pregnancies: An observational study

OBJECTIVE

To analyze the influence of the resting interval after removal of a double-balloon for cervical ripening and oxytocin administration on the time to onset of active labor in singleton pregnancies.

METHODS

A retrospective cohort study of women who required a cervical ripening with double-balloon was conducted between January 2019 and December 2022. We collected data for cervical ripening balloon insertion and removal, oxytocin administration, suspicious or pathological cardiotocographic trace, mode of delivery, maternal and neonatal complications, neonatal outcomes. Proportional hazards model comparing resting interval between double-balloon cervical ripening removal and oxytocin administration.

RESULTS

A total of 403 singleton pregnancies were recruited and 213 pregnant women experienced a rest of 12 h between cervical balloon removal and oxytocin administration (resting group). Oxytocin was administered immediately after balloon removal in 190 women (non-resting group). Median insertion-to-active labor interval and insertion-to-delivery interval were significantly shorter in the non-resting group: 18.5 versus 24.0 h, HR 2.59 (CI 95%: 1.97-3.41) and 24.0 versus 29.0 h, HR 2.38 (CI 95%: 1.85-3.05) respectively. Bishop score change and mode of delivery between were similar in both groups. No differences in maternal nor neonatal complications between both groups were found.

CONCLUSIONS

Oxytocin administration immediately after removal of a double-balloon for cervical ripening compared with 12 h delayed interval resulted in a shortened time from insertion to active labor onset and to delivery interval without increasing maternal or neonatal adverse outcomes.

An Externally Validated Model to Predict Prolonged Induction of Labor with an Unfavorable Cervix

OBJECTIVE

 To develop and externally validate a prediction model to calculate the likelihood of prolonged induction of labor (induction start to delivery time > 36 hours).

STUDY DESIGN

 This was a retrospective cohort study of all nulliparous women with singleton pregnancies and vertex presentation at term who underwent induction of labor and had a vaginal delivery at a single academic center. Women with contraindications for vaginal delivery were excluded. Analyses were limited to women with unfavorable cervix (both simplified Bishop score [dilation, station, and effacement: range 0-9] <6 and cervical dilation <3 cm). Prolonged induction of labor was defined as the duration of induction (induction start time to delivery) longer than 36 hours. A backward stepwise logistic regression analysis was used to identify the factors associated with prolonged induction of labor by considering maternal characteristics and comorbidities as well as fetal conditions. The final model was validated using an external dataset of the Consortium on Safe Labor after applying the same inclusion and exclusion criteria. We developed a receiver observer characteristic curve with area under the curve (AUC) in validation cohorts.

RESULTS

 Of 2,118 women, 364 (17%) had prolonged induction of labor. Factors associated with prolonged induction of labor included body mass index at admission, hypertension, fetal conditions, and epidural. Factors including younger maternal age, prelabor rupture of membranes, and a more favorable simplified Bishop score were associated with a decreased likelihood of prolonged induction of labor. In the external validation cohort, 4,418 women were analyzed, of whom 188 (4%) had prolonged induction of labor. The AUC of the final model was 0.76 (95% confidence interval: 0.73-0.80) for the external validation cohort. The online calculator was created and is available at: https://medstarapps.org/obstetricriskcalculator.

CONCLUSION

 Our externally validated model was efficient in predicting prolonged induction of labor with an unfavorable cervix.

KEY POINTS

· The number of inductions of labor at 39 weeks' gestation and beyond has been increasing.. · Our model had a good prediction of prolonged induction of labor.. · An online calculator has been created and available..

Methods for the induction of labor: efficacy and safety

This review assessed the efficacy and safety of pharmacologic agents (prostaglandins, oxytocin, mifepristone, hyaluronidase, and nitric oxide donors) and mechanical methods (single- and double-balloon catheters, laminaria, membrane stripping, and amniotomy) and those generally considered under the rubric of complementary medicine (castor oil, nipple stimulation, sexual intercourse, herbal medicine, and acupuncture). A substantial body of published reports, including 2 large network meta-analyses, support the safety and efficacy of misoprostol (PGE1) when used for cervical ripening and labor induction. Misoprostol administered vaginally at doses of 50 μg has the highest probability of achieving vaginal delivery within 24 hours. Regardless of dosing, route, and schedule of administration, when used for cervical ripening and labor induction, prostaglandin E2 seems to have similar efficacy in decreasing cesarean delivery rates. Globally, although oxytocin represents the most widely used pharmacologic agent for labor induction, its effectiveness is highly dependent on parity and cervical status. Oxytocin is more effective than expectant management in inducing labor, and the efficacy of oxytocin is enhanced when combined with amniotomy. However, prostaglandins administered vaginally or intracervically are more effective in inducing labor than oxytocin. A single 200-mg oral tablet of mifepristone seems to represent the lowest effective dose for cervical ripening. The bulk of the literature assessing relaxin suggests this agent has limited benefit when used for this indication. Although intracervical injection of hyaluronidase may cause cervical ripening, the need for intracervical administration has limited the use of this agent. Concerning the vaginal administration of nitric oxide donors, including isosorbide mononitrate, isosorbide, nitroglycerin, and sodium nitroprusside, the higher incidence of side effects with these agents has limited their use. A synthetic hygroscopic cervical dilator has been found to be effective for preinduction cervical ripening. Although a pharmacologic agent may be administered after the use of the synthetic hygroscopic dilator, in an attempt to reduce the interval to vaginal delivery, concomitant use of mechanical and pharmacologic methods is being explored. Combining the use of a single-balloon catheter with dinoprostone, misoprostol, or oxytocin enhances the efficacy of these pharmacologic agents in cervical ripening and labor induction. The efficacy of single- and double-balloon catheters in cervical ripening and labor induction seems similar. To date, the combination of misoprostol with an intracervical catheter seems to be the best approach when balancing delivery times with safety. Although complementary methods are occasionally used by patients, given the lack of data documenting their efficacy and safety, these methods are rarely used in hospital settings.

Time from insertion to expulsion of cervical ripening balloon in preterm versus term inductions of labor

OBJECTIVE

Preterm induction of labor can be necessary for maternal and fetal wellbeing. Duration of cervical ripening balloon (CRB) use has been studied in only term inductions. Our study investigated duration of time in hours for CRB expulsion and vaginal delivery in preterm inductions of labor.

METHODS

This was a single-institution retrospective cohort study of preterm (< 37 weeks) and term (≥ 37 weeks) inductions with CRB between 2010 and 2021. Cesarean deliveries were excluded. Primary outcome was insertion to expulsion time of CRB. Secondary outcomes included induction to delivery time, cervical dilation after expulsion, misoprostol, and Pitocin use. Institutional review board (IRB) approval was obtained prior to the study.

RESULTS

Ninety-eight patients with vaginal delivery after preterm CRB use were identified and matched 1:1 on baseline characteristics (p > 0.05) to term patients with vaginal delivery after CRB use. Mean insertion to expulsion time was significantly shorter for term than preterm inductions (mean 7.2 ± 3.09 h versus 8.5 ± 3.38 h; p < 0.01). Mean induction to delivery time was significantly shorter for term than preterm inductions (18.4 ± 7.6 h versus 22.5 ± 9.01 h; p < 0.01). Increased use of misoprostol, Pitocin, and second CRB were noted among the preterm cohort. Among term patients, more CRB placement at start of induction and greater cervical dilation post-balloon were found in comparison to preterm patients.

CONCLUSION

Among patients undergoing preterm induction, longer insertion to expulsion time of CRB, longer induction to delivery time, and increased interventions should be expected. Different standards for labor management should be considered for achieving vaginal delivery in preterm inductions.

Accidental rupture of membranes and neonatal infection after labor induction with silicone or latex balloon catheters: A retrospective cohort study

OBJECTIVE(S)

Accidental rupture of membranes (acROM), an insertion-related complication of the balloon catheter for labor induction, may prolong the duration of ruptured membranes. Prolonged rupture of membranes is associated with an increased risk of intra-uterine infection with possibly neonatal infection as result. Little is known about safety profiles of different catheters regarding the occurrence of these complications. This study compares the incidence of neonatal early-onset sepsis (EOS) and acROM in women receiving either silicone or latex balloon catheters.

STUDY DESIGN

A retrospective cohort study was performed including 2200 women (silicone balloon catheter, n = 1100 vs. latex balloon catheter, n = 1100). The primary outcomes were the incidence of acROM, and suspected and proven neonatal EOS. Secondary outcomes were: prolonged rupture of membranes, intrapartum fever, pre- or postnatal neonatal exposure to antibiotics, and perinatal outcomes. A subgroup analysis was performed between women with and without acROM.

RESULTS

No statistically significant difference with regard to suspected or proven EOS was seen between the silicone and latex groups. The acROM rate was significantly higher in the silicone group compared to the latex group (2.9 % and 0.3 %, p < 0.01). Prolonged rupture of membranes was significantly more common in the silicone group compared to the latex group (5.0 % and 2.4 %, p < 0.01), as was the use of intrapartum antibiotics (12.7 % and 9.6 %, p = 0.02). Neonates were significantly more often exposed to pre- or postnatal antibiotics in the silicone group compared to the latex group (17.6 % and 13.6 %, p = 0.01). Subgroup analysis showed significantly more suspected and proven neonatal EOS when catheter-insertion was complicated with acROM (11.4 % and 20.0 %), compared to cases without acROM (3.8 % and 2.5 %), irrespective of the type of catheter used.

CONCLUSION(S)

The use of silicone balloon catheters for labor induction results in higher rates of acROM, prolonged rupture of membranes and use of intrapartum antibiotics, compared to latex balloon catheters. No statistically significant differences were found in the occurrence of suspected or proven neonatal EOS, however neonates from the silicone group were more often exposed to pre- or postnatal antibiotics. When acROM occurs, irrespective of type of catheter used, suspected and proven neonatal EOS was seen more often.

Double-vs single-balloon catheter for induction of labor: Systematic review and individual participant data meta-analysis

INTRODUCTION

Evidence comparing double-balloon vs single-balloon catheter for induction of labor is divided. We aim to compare the efficacy and safety of double-vs single-balloon catheters using individual participant data.

MATERIAL AND METHODS

A search of Ovid MEDLINE, Embase, Ovid Emcare, CINAHL Plus, Scopus, and clinicaltrials.gov was conducted for randomized controlled trials published from March 2019 until April 13, 2021. Earlier trials were identified from the Cochrane Review on Mechanical Methods for Induction of Labour. Randomized controlled trials that compared double-balloon with single-balloon catheters for induction of labor in singleton gestations were eligible. Participant-level data were sought from trial investigators and an individual participant data meta-analysis was performed. The primary outcomes were rates of vaginal birth achieved, a composite measure of adverse maternal outcomes and a composite measure of adverse perinatal outcomes. We used a two-stage random-effects model. Data were analyzed from the intention-to-treat perspective.

RESULTS

Of the eight eligible randomized controlled trials, three shared individual-level data with a total of 689 participants, 344 women in the double-balloon catheter group and 345 women in the single-balloon catheter group. The difference in the rate of vaginal birth between double-balloon catheter and single-balloon catheter was not statistically significant (relative risk [RR] 0.93, 95% confidence interval [CI] 0.86-1.00, p = 0.050; I2 0%; moderate-certainty evidence). Both perinatal outcomes (RR 0.81, 95% CI 0.54-1.21, p = 0.691; I2 0%; moderate-certainty evidence) and maternal composite outcomes (RR 0.65, 95% CI 0.15-2.87, p = 0.571; I2 55.46%; low-certainty evidence) were not significantly different between the two groups.

CONCLUSIONS

Single-balloon catheter is at least comparable to double-balloon catheter in terms of vaginal birth rate and maternal and perinatal safety outcomes.

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 reduction in side effects that could improve neonatal outcomes. This is an update of a review first published in 2001, last updated in 2012.

OBJECTIVES

To determine the effectiveness and safety of mechanical methods for third trimester (> 24 weeks' gestation) induction of labour in comparison with prostaglandin E2 (PGE2) (vaginal and intracervical), low-dose misoprostol (oral and vaginal), amniotomy or oxytocin.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies (9 January 2018). We updated the search in March 2019 and added the search 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 pharmacological methods. Mechanical methods include: (1) the introduction of a catheter through the cervix into the extra-amniotic space with balloon insufflation; (2) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (3) use of a catheter to inject fluid into the extra-amniotic space (EASI). This review includes the following comparisons: (1) specific mechanical methods (balloon catheter, laminaria tents or EASI) compared with prostaglandins (different types, different routes) or with oxytocin; (2) single balloon compared to a double balloon; (3) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins or oxytocin alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

This review includes a total of 112 trials, with 104 studies contributing data (22,055 women; 21 comparisons). Risk of bias of trials varied. Overall, the evidence was graded from very-low to moderate quality. All evidence was downgraded for lack of blinding and, for many comparisons, the effect estimates were too imprecise to make a valid judgement.   Balloon versus vaginal PGE2: there may be little or no difference in vaginal deliveries not achieved within 24 hours (risk ratio (RR) 1.01, 95% confidence interval (CI) 0.82 to 1.26; 7 studies; 1685 women; low-quality evidence) and there probably is little or no difference in caesarean sections (RR 1.00, 95% CI 0.92 to 1.09; 28 studies; 6619 women; moderate-quality evidence) between induction of labour with a balloon catheter and vaginal PGE2. A balloon catheter probably reduces the risk of uterine hyperstimulation with fetal heart rate (FHR) changes (RR 0.35, 95% CI 0.18 to 0.67; 6 studies; 1966 women; moderate-quality evidence), serious neonatal morbidity or perinatal death (RR 0.48, 95% CI 0.25 to 0.93; 8 studies; 2757 women; moderate-quality evidence) and may slightly reduce the risk of aneonatal intensive care unit (NICU) admission (RR 0.82, 95% CI 0.65 to 1.04; 3647 women; 12 studies; low-quality evidence). It is uncertain whether there is a difference in serious maternal morbidity or death (RR 0.20, 95% CI 0.01 to 4.12; 4 studies; 1481 women) or five-minute Apgar score < 7 (RR 0.74, 95% CI 0.49 to 1.14; 4271 women; 14 studies) because the quality of the evidence was found to be very low and low, respectively. Balloon versus low-dose vaginal misoprostol: it is uncertain whether there is a difference in vaginal deliveries not achieved within 24 hours between induction of labour with a balloon catheter and vaginal misoprostol (RR 1.09, 95% CI 0.85 to 1.39; 340 women; 2 studies; low-quality evidence). A balloon catheter probably reduces the risk of uterine hyperstimulation with FHR changes (RR 0.39, 95% CI 0.18 to 0.85; 1322 women; 8 studies; moderate-quality evidence) but may increase the risk of a caesarean section (RR 1.28, 95% CI 1.02 to 1.60; 1756 women; 12 studies; low-quality evidence). It is uncertain whether there is a difference in serious neonatal morbidity or perinatal death (RR 0.58, 95% CI 0.12 to 2.66; 381 women; 3 studies), serious maternal morbidity or death (no events; 4 studies, 464 women), both very low-quality evidence, and five-minute Apgar score < 7 (RR 1.00, 95% CI 0.50 to 1.97; 941 women; 7 studies) and NICU admissions (RR 1.00, 95% CI 0.61 to 1.63; 1302 women; 9 studies) both low-quality evidence. Balloon versus low-dose oral misoprostol: a balloon catheter probably increases the risk of a vaginal delivery not achieved within 24 hours (RR 1.28, 95% CI 1.13 to 1.46; 782 women, 2 studies, and probably slightly increases the risk of a caesarean section (RR 1.17, 95% CI 1.04 to 1.32; 3178 women; 7 studies; both moderate-quality evidence) when compared to oral misoprostol. It is uncertain whether there is a difference in uterine hyperstimulation with FHR changes (RR 0.81, 95% CI 0.48 to 1.38; 2033 women; 2 studies), serious neonatal morbidity or perinatal death (RR 1.11, 95% CI 0.60 to 2.06; 2627 women; 3 studies), both low-quality evidence, serious maternal morbidity or death (RR 0.50, 95% CI 0.05 to 5.52; 2627 women; 3 studies), very low-quality evidence, five-minute Apgar scores < 7 (RR 0.71, 95% CI 0.38 to 1.32; 2693 women; 4 studies) and NICU admissions (RR 0.82, 95% CI 0.58 to 1.17; 2873 women; 5 studies) both low-quality evidence.

AUTHORS' CONCLUSIONS

Low- to moderate-quality evidence shows mechanical induction with a balloon is probably as effective as induction of labour with vaginal PGE2. However, a balloon seems to have a more favourable safety profile. More research on this comparison does not seem warranted. Moderate-quality evidence shows a balloon catheter may be slightly less effective as oral misoprostol, but it remains unclear if there is a difference in safety outcomes for the neonate. When compared to low-dose vaginal misoprostol, low-quality evidence shows a balloon may be less effective, but probably has a better safety profile. Future research could be focused more on safety aspects for the neonate and maternal satisfaction.

Safety and efficacy of double-balloon catheter for cervical ripening: a Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

Various methods are used for cervical ripening during the induction of labor. Mechanical and pharmacological methods are commonly used for cervical ripening. A double-balloon catheter was specifically developed to ripen the cervix and induce labor; however, the efficacy of the double-balloon catheter in cervical ripening compared to other methods is unknown.

METHODS

We searched five databases and performed a Bayesian network meta-analysis. Six interventions (double-balloon catheter, Foley catheter, oral misoprostol, vaginal misoprostol, dinoprostone, and double-balloon catheter combined with oral misoprostol) were included in the search. The primary outcomes were cesarean delivery rate and time from intervention-to-birth. The secondary outcomes were as follows: Bishop score increment; achieving a vaginal delivery within 24 h; uterine hyperstimulation with fetal heart rate changes; need for oxytocin augmentation; instrumental delivery; meconium staining; chorioamnionitis; postpartum hemorrhage; low Apgar score; neonatal intensive care unit admission; and arterial pH.

RESULTS

Forty-eight randomized controlled trials involving 11,482 pregnant women were identified. The cesarean delivery rates of the cervical ripening with a double-balloon catheter and oral misoprostol, oral misoprostol, and vaginal misoprostol were significantly lower than cervical ripening with a Foley catheter (OR = 0.48, 95% CI: 0.23-0.96; OR = 0.74, 95% CI: 0.58-0.93; and OR = 0.79, 95% CI: 0.64-0.97, respectively; all P < 0.05). The time from intervention-to-birth of vaginal misoprostol was significantly shorter than the other five cervical ripening methods. Vaginal misoprostol and oral misoprostol increased the risk of uterine hyperstimulation with fetal heart rate changes compared to a Foley catheter. A double-balloon catheter with or without oral misoprostol had similar outcomes, including uterine hyperstimulation with fetal heart rate changes compared to a Foley catheter.

CONCLUSION

Double-balloon catheter did not show superiority when compared with other single method in primary and secondary outcomes of labor induction. The combination of double-balloon catheter with oral misoprostol was significantly reduced the rate of cesarean section compared to Foley catheter without increased risk of uterine hyperstimulation with fetal heart rate changes, which was shown in oral or vaginal misoprostol.

Towards an evidence-based approach to optimize the success of labour induction

Induction of labour is a two-step process involving cervical ripening and the initiation of uterine contractions, with the goal of achieving vaginal birth. To optimize the chance of a safe and timely vaginal birth, the process of induction of labour should be evidence based and individualized to the given person and situation. In this study, we lay out a framework for how this should be done, emphasizing on careful clinical assessment and planning, flexibility in the strategy of induction, patience during the ripening and latent phases of labour, and thoughtful consideration regarding changing the strategy if active labour is not initially achieved. The goal of this review is to present the current evidence on this topic in the form of a user-friendly protocol that can be easily adapted to institutional practice.

Double Foley catheter for labor induction: An alternative method

OBJECTIVE

To introduce a new handmade device, the double Foley catheter (DFC), and compare it with the Foley catheter (FC) and Cook cervical ripening balloon for its effectiveness in labor induction.

METHODS

This prospective randomized controlled trial included 222 patients with unfavorable cervices. The patients were randomly allocated to the DFC, FC, and Cook cervical ripening balloon groups (n = 74 patients per group). The outcomes were evaluated using SPSS v. 23.

RESULTS

Bishop scores successfully increased with all three methods (P = 0.000 for all groups), and the rates of vaginal delivery within 24 and 48 h were similar (P = 0.101 and P = 0.390, respectively). The pain scores of the DFC and Cook cervical ripening balloon groups were similar, but were lower than those of the FC group (P = 0.011). The overall maternal satisfaction scores of the DFC and Cook cervical ripening balloon groups were not significantly different but were higher than those of the FC group (P = 0.014).

CONCLUSION

The maternal safety and success rate of labor induction were comparable between groups. However, the FC group had a higher pain score during catheter insertion and a lower maternal satisfaction rate. Moreover, considering the high cost of the Cook cervical ripening balloon, the DFC has an advantage, especially in low-resource countries.

Multicentre randomised controlled trial comparing the safety in the first 12 h, efficacy and maternal satisfaction of a double balloon catheter and prostaglandin pessary for induction of labour

OBJECTIVE

To evaluate the safety in the first 12 h, efficacy and maternal satisfaction of a double balloon catheter (DBC) with vaginal prostaglandin (PGE) for induction of labour (IOL).

METHODS

We conducted a multicentre randomised controlled study of 420 patients from 1st January 2016 to 31st December 2017 to evaluate the use of DBC in IOL in an Asian population looking at the adverse effects in the first 12 h after insertion. Women were assigned randomly to cervical ripening with either a DBC or a prostaglandin pessary. The adverse events in the 12 h after DBC or first prostaglandin inserted, the efficacy of a DBC to a prostaglandin in labour induction and maternal satisfaction were evaluated.

RESULTS

There were significantly less women with uterine hyperstimulation in the DBC (2 vs 24, p ≤ 0.0001) compared to the prostaglandin group. There were no women with uterine hyperstimulation and non-reassuring foetal status in the DBC while there were 5 women with uterine hyperstimulation and foetal distress in the prostaglandin group. Use of entonox was significantly less in the DBC group (p = 0.009). There were no significant differences in both groups in caesarean section, vaginal deliveries and time to delivery, although significant less time was needed to achieve cervical os dilation more than 4 cm in the DBC group (p ≤ 0.0001). Neonatal birth outcomes were similar. Women's pain scores were similar for both methods. 80.1% of women allocated the DBC and 76.8% of women allocated the PGE were keen to recommend their method of induction.

CONCLUSION

Double balloon catheter remains a good alternative method for inducing women in view of a good safety profile with low risk of hyperstimulation and high maternal satisfaction.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02620215.

Massive antepartum haemorrhage at insertion of Foley balloon catheter for induction of labour

Induction of labour using a balloon catheter is common practice throughout the world, often used in high-risk pregnancies due to the improved safety profile for the fetus compared with pharmacological methods. This report outlines the case of a 2500 mL antepartum haemorrhage on placement of a Foley catheter through the cervix at a secondary obstetric unit in New Zealand. An emergency caesarean section was carried out 20 min after the bleeding onset. No obvious cause for the bleeding was identified at caesarean. The mother required a blood transfusion, but otherwise, did well clinically; the infant required resuscitation at birth and went on to suffer a left middle cerebral artery stroke. At 6 months, he is assumed to have recovered with no long-term sequelae. A literature review has highlighted this was an unprecedented event. We hope to raise awareness of this rare catastrophic adverse outcome given the prevalence of balloon catheter induction.

Induction of labor in continuing pregnancies

This chapter aims to provide an evidence-based approach to cervical-ripening methods and induction of labor in high-, middle-, and low-income countries. We will review the epidemiology of induction and will also review pharmacological and mechanical methods of cervical-ripening as well as oxytocin for induction. Lastly, we will review current guidelines of when to determine an induction to be failed.

Cervical ripening: Why we do what we do

More than 20% of pregnant women have their labor induced and at least half of them will require cervical ripening due to an unfavorable starting cervical exam. The use of cervical ripening methods has been shown to decrease the risk of cesarean delivery when compared to initiating an induction with oxytocin in women with an unfavorable cervix. However, among the different cervical ripening methods themselves, while there may be differences in time to delivery and differences in the safety profile of different cervical ripening methods, there is no clear evidence that any one cervical ripening method reduces the risk of cesarean compared to another method. The objectives of this manuscript are to discuss the pathophysiology of cervical ripening including the biochemical processes that lead to cervical ripening; to review the different methods of cervical ripening including both mechanical and pharmacologic methods, and to evaluate the evidence and efficacy for different doses, routes, and techniques employed when using various cervical ripening methods.

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 reduction in side effects that could improve neonatal outcomes. This is an update of a review first published in 2001, last updated in 2012.

OBJECTIVES

To determine the effectiveness and safety of mechanical methods for third trimester (> 24 weeks' gestation) induction of labour in comparison with prostaglandin E2 (PGE2) (vaginal and intracervical), low-dose misoprostol (oral and vaginal), amniotomy or oxytocin.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies (9 January 2018). We updated the search in March 2019 and added the search 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 pharmacological methods.Mechanical methods include: (1) the introduction of a catheter through the cervix into the extra-amniotic space with balloon insufflation; (2) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (3) use of a catheter to inject fluid into the extra-amniotic space (EASI).This review includes the following comparisons: (1) specific mechanical methods (balloon catheter, laminaria tents or EASI) compared with prostaglandins (different types, different routes) or with oxytocin; (2) single balloon compared to a double balloon; (3) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins or oxytocin alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

This review update includes a total of 113 trials (22,373 women) contributing data to 21 comparisons. Risk of bias of trials varied. Overall, the evidence was graded from very-low to moderate quality. All evidence was downgraded for lack of blinding and, for many comparisons, the effect estimates were too imprecise to make a valid judgement.Balloon versus vaginal PGE2: there may be little or no difference in vaginal deliveries not achieved within 24 hours (average risk ratio (RR) 1.01, 95% confidence interval (CI) 0.82 to 1.26; 7 studies; 1685 women; I² = 79%; low-quality evidence) and there probably is little or no difference in caesarean sections (RR 1.00, 95% CI 0.92 to 1.09; 28 studies; 6619 women; moderate-quality evidence) between induction of labour with a balloon catheter and vaginal PGE2. A balloon catheter probably reduces the risk of uterine hyperstimulation with fetal heart rate (FHR) changes (RR 0.35, 95% CI 0.18 to 0.67; 6 studies; 1966 women; moderate-quality evidence), serious neonatal morbidity or perinatal death (RR 0.48, 95% CI 0.25 to 0.93; 8 studies; 2757 women; moderate-quality evidence) and may slightly reduce the risk of aneonatal intensive care unit (NICU) admission (RR 0.82, 95% CI 0.65 to 1.04; 3647 women; 12 studies; low-quality evidence). It is uncertain whether there is a difference in serious maternal morbidity or death (RR 0.20, 95% CI 0.01 to 4.12; 4 studies; 1481 women) or five-minute Apgar score < 7 (RR 0.74, 95% CI 0.49 to 1.14; 4271 women; 14 studies) because the quality of the evidence was found to be very low and low, respectively.Balloon versus low-dose vaginal misoprostol: it is uncertain whether there is a difference in vaginal deliveries not achieved within 24 hours between induction of labour with a balloon catheter and vaginal misoprostol (RR 1.09, 95% CI 0.85 to 1.39; 340 women; 2 studies; low-quality evidence). A balloon catheter probably reduces the risk of uterine hyperstimulation with FHR changes (RR 0.39, 95% CI 0.18 to 0.85; 1322 women; 8 studies; moderate-quality evidence) but may increase the risk of a caesarean section (average RR 1.28, 95% CI 1.02 to 1.60; 1756 women; 12 studies; I² = 45%; low-quality evidence). It is uncertain whether there is a difference in serious neonatal morbidity or perinatal death (RR 0.58, 95% CI 0.12 to 2.66; 381 women; 3 studies), serious maternal morbidity or death (no events; 4 studies, 464 women), both very low-quality evidence, and five-minute Apgar score < 7 (RR 1.00, 95% CI 0.50 to 1.97; 941 women; 7 studies) and NICU admissions (RR 1.00, 95% CI 0.61 to 1.63; 1302 women; 9 studies) both low-quality evidence.Balloon versus low-dose oral misoprostol: a balloon catheter probably increases the risk of a vaginal delivery not achieved within 24 hours (RR 1.28, 95% CI 1.13 to 1.46; 782 women, 2 studies, and probably slightly increases the risk of a caesarean section (RR 1.17, 95% CI 1.04 to 1.32; 3178 women; 7 studies; both moderate-quality evidence) when compared to oral misoprostol. It is uncertain whether there is a difference in uterine hyperstimulation with FHR changes (RR 0.81, 95% CI 0.48 to 1.38; 2033 women; 2 studies), serious neonatal morbidity or perinatal death (RR 1.11, 95% CI 0.60 to 2.06; 2627 women; 3 studies), both low-quality evidence, serious maternal morbidity or death (RR 0.50, 95% CI 0.05 to 5.52; 2627 women; 3 studies), very low-quality evidence, five-minute Apgar scores < 7 (RR 0.71, 95% CI 0.38 to 1.32; 2693 women; 4 studies) and NICU admissions (RR 0.82, 95% CI 0.58 to 1.17; 2873 women; 5 studies) both low-quality evidence.

AUTHORS' CONCLUSIONS

Low- to moderate-quality evidence shows mechanical induction with a balloon is probably as effective as induction of labour with vaginal PGE2. However, a balloon seems to have a more favourable safety profile. More research on this comparison does not seem warranted.Moderate-quality evidence shows a balloon catheter may be slightly less effective as oral misoprostol, but it remains unclear if there is a difference in safety outcomes for the neonate. When compared to low-dose vaginal misoprostol, low-quality evidence shows a balloon may be less effective, but probably has a better safety profile.Future research could be focused more on safety aspects for the neonate and maternal satisfaction.

Double- versus single-balloon catheters for labour induction and cervical ripening: a meta-analysis

Background

The induction of labour is an increasingly common procedure in the obstetrics field. Various methods have been used to induce labour, among which balloon catheters play an important role. Whether the specifically designed double-balloon catheter is better than the single-balloon device in terms of efficacy, efficiency, safety and patient satisfaction remains controversial. Identifying even small differences between these two devices could be useful to guide clinical practices, to further explore their mechanisms, and to promote a better understanding of the optimal methods for inducing labour.

Methods

Using the population, intervention, comparison, outcomes and study designs (PICOS) principle, we searched the PubMed, EMBASE, OVID, SCI, CENTRAL, ClinicalTrial.gov, and CDSR databases to identify relevant randomised controlled trials (RCTs) from inception through February 14, 2018. The primary outcome was the caesarean delivery rate, and the secondary outcomes focused on efficacy, efficiency, safety, and patient satisfaction. The relative risks or mean differences, including their 95% confidence intervals, were calculated using fixed-effects or random-effects models. All statistical analyses were completed with RevMan version 5.3.

Results

From a total of 1326 articles, 7 RCTs involving 1159 women were included. There were no significant differences in primary outcomes (RR, 0.88 [0.65, 1.2]; p-value, 0.43) or secondary outcomes identified between single- and double-balloon catheters. However, heterogeneity existed for some aspects.

Conclusion

Both kinds of balloon catheter have similar levels of efficacy, efficiency, safety and patient satisfaction; however, the single-balloon method is considered to be more cost-effective.

Single versus multiple cervical dilation by osmotic dilator before induction of labor for second-trimester abortion

AIM

In this study, we aimed to investigate whether there was a significant prognostic difference between single and multiple cervical dilations when inducing second-trimester abortion.

METHODS

We conducted a retrospective review of 238 pregnant women who underwent termination of pregnancy at 12-21 weeks of gestation at Osaka University Hospital in Osaka, Japan, between January 2010 and May 2018. Termination of pregnancy was performed by vaginal administration of 1 mg gemeprost every 3 h for up to five doses per day after uterine cervical dilation using lamicel.

RESULTS

The women were categorized into two groups: 191 women had a delivery time of <24 h, whereas 47 had delivery times >24 h. Contrasting the groups, there were significant differences with regard to numbers of primiparas (88 [46.1%] and 32 [68.1%], respectively) and lamicel exchanges ± SD (1.9 ± 0.67 for <24 h and 2.4 ± 0.87 for >24 h, respectively). Additionally, we compared the prognosis of primiparas that received just a single lamicel with that of primiparas that had ≥2 exchanged, but no significant differences were noted in the number of patients with a delivery time of >24 h and the number of used gemeprost.

CONCLUSION

Primipara is a risk factor for delayed delivery time of induced abortion. However, increasing the number of exchanged lamicel did not significantly reduce the delivery time; therefore, it should be performed as minimally as possible.

Double-balloon catheter versus dinoprostone insert for labour induction: a meta-analysis

OBJECTIVE

To assess the efficacy and safety of a double-balloon catheter versus dinoprostone insert for labour induction.

STUDY DESIGN

PubMed, MEDLINE, Embase, ClinicalTrials.gov, and the Cochrane Central Register of Clinical Trials databases were searched from 1985 to April 2018. Randomized controlled trials that compared a double-balloon catheter and dinoprostone insert for cervical ripening were identified. Eligible study populations consisted of women with singleton pregnancies that had any indication for labour induction and were randomly assigned to undergo induction with a double-balloon catheter or dinoprostone insert. The main outcomes were incidence of vaginal delivery within 24 h and caesarean section, and neonatal outcomes.

RESULTS

Five randomized trials (603 women; 305 with a double-balloon catheter and 298 with a dinoprostone insert) were eligible for inclusion. No differences were observed between the two groups in terms of vaginal delivery within 24 h [relative risk (RR) 1.21, 95% confidence interval (CI) 0.93-1.59] and incidence of caesarean section (RR 0.99, 95% CI 0.77-1.27). Compared with the double-balloon catheter, the dinoprostone insert was associated with a reduced need for oxytocin administration in the process of labour induction (RR 1.95, 95% CI 1.45-2.62). However, there was a higher incidence of excessive uterine activity (RR 0.17, 95% CI 0.06-0.54) and neonatal umbilical cord arterial blood pH < 7.1 (RR 0.36, 95% CI 0.15-0.84) in the dinoprostone insert group.

CONCLUSION

This review showed that the efficacy of labour induction using both the double-balloon catheter and dinoprostone insert was similar. However, the double-balloon catheter seemed to be a safer method.

Challenges and Limitations of Clinical Trials on Labor Induction: A Review of the Literature

Induction of labor is a common obstetric procedure performed in nearly a quarter of all deliveries in the United States. Pharmacological (prostaglandins, oxytocin) and/or mechanical methods (balloon catheters) are commonly used for labor induction; however, there is ongoing debate as to which method is the safest and most effective. This narrative review discusses key limitations of published trials on labor induction, including the lack of well-designed randomized controlled trials directly comparing specific methods of induction, heterogeneous trial populations, and wide variation in the protocols used and outcomes reported. Furthermore, the majority of published trials were underpowered to detect significant differences in the most clinically relevant efficacy and safety outcomes (e.g., cesarean delivery, neonatal mortality). By identifying the limitations of labor induction trials, we hope to highlight the importance of quality published data to better inform guidelines and drive evidence-based treatment decisions.

Efficiency of the Foley catheter versus the double balloon catheter during the induction of second trimester pregnancy terminations: a randomized controlled trial

PURPOSE

To compare induction-to-delivery intervals of Foley catheters and double balloon catheters in second trimester pregnancy terminations.

METHODS

This randomized parallel study was conducted on women who underwent second trimester terminations between December 2016 and December 2017. Pregnant women in the second trimester with a Bishop score < 6 were included in the study. Participants were randomized into two groups, the first being the Foley catheter group and the second being the double balloon catheter group. The time frames from insertion of catheters to the delivery were recorded in each group. A multiple regression analysis was carried out to examine the contribution of factors to the induction-to-delivery interval. A survival analysis was conducted to compare the Foley method and the double balloon method.

RESULTS

A total of 91 pregnant women were included in the final analysis. The induction-to-delivery interval was shorter in the Foley catheter group than in the double balloon catheter group (38 h 54 min ± 21 h 6 min versus 58 h 17 min ± 25 h 56 min). We also found that women with intrauterine fetal death (IUFD) had a shorter time to delivery compared to women with live fetuses (39 h 12 min ± 18 h 46 min vs 51 h 30 min ± 26 h 42 min, p = 0.04). Women with a history of vaginal delivery also had a shorter induction-to-delivery time compared to women who never delivered vaginally before (38 h 12 min ± 17 h 42 min vs 53 h 54 min ± 27 h 18 min, p = 0.004). In the multiple regression analysis, the most significant contributor to the induction-to-delivery time was the method used for induction of labor and followed by other factors including the viability of the fetus (live/IUFD), history of vaginal delivery and PPROM. The survival analysis showed that the induction-to-delivery interval was significantly shorter in the Foley catheter group than in the double balloon catheter group (HR 2.51, 95% CI 1.57-4.00, p = 0.001).

CONCLUSION

During the termination of second trimester pregnancies time from induction of labor to delivery is shorter with the Foley catheter compared to double balloon catheter.

Patient satisfaction with the cervical ripening balloon as a method for induction of labour: a randomised controlled trial

INTRODUCTION

Evidence has shown that balloon catheters are as effective as prostaglandins (PGE) in achieving vaginal delivery within 24 hours of the start of induction of labour (IOL), with lower rates of uterine hyperstimulation, and similar Caesarean section and infection rates. International guidelines recommend mechanical methods as a method of IOL. We designed a prospective randomised controlled study to evaluate patient acceptance of the cervical ripening balloon (CRB) for IOL.

METHODS

Suitable women with a singleton term pregnancy without major fetal anomaly suitable for vaginal delivery were recruited and randomised to receive the CRB or PGE on the day of IOL. Characteristics of the women, labour and birth outcomes were obtained from case notes. Pain and satisfaction scores were obtained by interviewing the women at IOL and after delivery. The main outcome measures were participant characteristics, labour and birth outcomes, pain score, satisfaction scores, and whether the participant would recommend the mode of IOL.

RESULTS

There was no difference in the pain score between the two groups at the start of IOL, but thereafter, pain scores were lower in the CRB group compared to the PGE group (4.5 ± 2.3 vs. 5.6 ± 2.4, p = 0.044). Women were equally satisfied with both methods and equally likely to recommend their method for IOL.

CONCLUSION

Patient experience of IOL with CRB or PGE was equally satisfactory, although pain during induction was lower in the CRB group. We found that both methods of IOL are acceptable to women and should be made available to provide more options.

[Cervical ripening and labor induction: Evaluation of single balloon catheter compared to double balloon catheter and dinoprostone insert]

OBJECTIVE

To compare the effectiveness of single balloon catheter with double balloon catheter and dinoprostone insert for cervical ripening and labor induction on unfavourable cervix.

METHODS

this is a comparative, retrospective, one-center trial. Were included singleton pregnancy in cephalic presentation. Were excluded cicatricial uterus. The outcomes were vaginal delivery rate, caesarean section rate, modification in Bishop score, time from induction to delivery, second time prostaglandin E2 resort, oxytocin administration resort, maternal or neonatal adverse events.

RESULTS

Were included 108 patients: 45 in single balloon catheter group, 32 in double balloon catheter group, 31 in dinoprostone insert group. Vaginal delivery rate was similar in single balloon catheter group (78 %) compared with others groups (75 % in double balloon catheter and 71 % in dinoprostone insert group respectively). Oxytocin administration resort was superior in single balloon catheter group. There was no significant difference on others outcomes. Labor induction costs were 9euros in single balloon catheter group, versus 55 and 81 euros in double balloon catheter group and dinoprostone insert group respectively.

CONCLUSIONS

Single balloon catheter seems just as effective as double balloon catheter and dinoprostone insert with its major asset the low cost for labor induction.

Comparison of single- and double-balloon catheters for labor induction: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

There is a paucity of head-to-head randomized trials that compare single- and double-balloon catheters, and the results of the available data in terms of time from catheter insertion to delivery and delivery mode are mixed. This meta-analysis of randomized controlled trials compares the efficacy of single- and double-balloon catheters in women undergoing labor induction.

STUDY DESIGN

Searches were made in MEDLINE, EMBASE, PubMed, ClinicalTrials.gov, and the Cochrane Library from inception through June 2016. Peer-reviewed randomized and quasi-randomized trials that compared single- and double-balloon catheters head-to-head for cervical ripening or labor induction were identified. Eligible study populations consisted of women with singleton pregnancies that had any indication for labor induction and were randomly assigned to undergo induction with a single- or a double-balloon catheter. The primary outcome was time from catheter insertion to delivery and delivery mode. The secondary outcomes were intrapartum fever or chorioamnionitis, woman's satisfaction, and neonatal Apgar score.

RESULTS

Of the 520 records identified, five randomized trials (996 women; 491 with single-balloon and 505 with double-balloon catheters) were considered eligible and included in the meta-analysis. Time from catheter insertion to delivery did not differ between the two types of catheter (p = 0.527; WMD -0.87; 95% CI: -3.55, 1.82). The incidence of cesarean delivery also did not differ (p = 0.844; RR 0.97; 95% CI: 0.69, 1.35). Delivery within 24 h, delivery mode, incidences of intrapartum fever or chorioamnionitis, and neonatal Apgar score <7 at 5 min did not differ between the two types of catheter as well. Women who were induced with the single-balloon catheter were more satisfied (p = 0.029; WMD 0.56; 95% CI: 0.06, 1.06).

CONCLUSION

Time from catheter insertion to delivery and delivery mode were comparable between the two types of catheter.

Single versus double-balloon catheters for the induction of labor of singleton pregnancies: a meta-analysis of randomized and quasi-randomized controlled trials

OBJECTIVE

To compare the efficacy of single- versus double-balloon catheter (SBC vs. DBC) for cervical ripening and labor induction with an unfavorable cervix.

METHODS

Systematic review and meta-analysis of randomized controlled trials (RCTs) or quasi-RCTs (qRCT) regarding the use of SBC or DBC for labor induction of live singleton cephalic pregnancies (≥ 35 weeks) of any parity with an unripe cervix (Bishop score ≤ 6). Nine research databases were searched for original articles published in all languages up to November 2017 comparing both devices for labor induction. Five RCTs and one qRCT were included. Primary outcome measures were time from intervention (device placement) to birth time, vaginal delivery and cesarean section rates, and maternal satisfaction with the procedure. Risk of bias was evaluated with the Cochrane tool. Random effects models were used to combine data for meta-analyses. Summary measures were reported as mean differences and risk ratios (RR) with 95% confidence intervals.

RESULTS

Regardless of parity, pooled analyses of the six trials (n = 1060 women) found that mean intervention to birth time, vaginal delivery and cesarean section rates, and maternal satisfaction to the procedure were similar for both studied groups (SBC vs. DBC).

CONCLUSION

Measured primary outcome measures were similar regardless of the type of device used for labor induction of singleton pregnancies.

Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour.

OBJECTIVE

To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups.

METHODS

We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group's Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012-13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves.

RESULTS

We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed 'best'. Few studies collected information on women's views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective.

LIMITATIONS

There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses.

CONCLUSIONS

Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention.

FUTURE WORK

Future trials should be powered to detect a method that is more cost-effective than misoprostol solution and report outcomes included in this NMA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Application effect of single balloon catheters in labor induction of pregnant women in late-term pregnancy and their influences on stress and inflammatory responses

This study was designed to evaluate the application effect of single balloon catheters and dinoprostone on promoting cervical ripening of pregnant women in late-term pregnancy and their influences on stress and inflammatory responses. A total of 160 pregnant women with indications of labor induction were included and randomly divided into the control (n=80) and observation (n=80) groups. Patients in the control group received labor induction by administration of dinoprostone at the vaginal vault, while those in the observation group received labor induction by domestic single balloon catheters. Cervical ripening (Bishop score), means of pregnancy, the total stage of labor, maternal and child complications, and Apgar scores of newborn infants at 1 min after delivery between the two groups were compared. At the prenatal and postpartum 12, 24 and 48 h, the levels of cortisol (COR), norepinephrine (NE) and β-endorphin (β-EP), were detected using radioimmunoassay, and those of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured using enzyme-linked immunosorbent assay (ELISA). Cervical Bishop scores in the two groups after intervention were significantly higher than those before intervention, and the score of the observation group was significantly higher than that of the control group. The difference was statistically significant (P<0.05). In the observation group, the total stage of labor was significantly shortened, the Apgar score of the newborn infant at 1 min after delivery was increased compared with those in the control group, and the differences were statistically significant (P<0.05). The delivery rate of cesarean section in the observation group was lower than that in the control group, the overall incidence rate of perinatal complications was decreased, and the differences were statistically significant (P<0.05). The levels of stress and inflammatory response markers at 12 h after delivery in the two groups reached the peak, and then declined (P<0.05). The levels of stress and inflammatory response markers at each time-point after delivery in the observation group were significantly lower than those in the control group, and the difference was statistically significant (P<0.05). The results showed that the single balloon catheter promotes cervical ripening, improves pregnancy outcomes and reduces the stress and inflammatory responses of pregnant women in late-term pregnancy, and is better than dinoprostone and has better application and promotion values.

Hygroscopic dilators vs balloon catheter ripening of the cervix for induction of labor in nulliparous women at term: Retrospective study

Objective

To compare the efficacy and safety of hygroscopic dilators and balloon catheters for ripening of the cervix in induction of labor.

Study design

This retrospective, observational study used data from the Successive Pregnancy Birth Registry System of the Japan Society of Obstetrics and Gynecology from 2012 to 2014. Nulliparous women in whom labor was induced by mechanical methods of cervical ripening at term were enrolled. The eligible women were divided into dilator, balloon <40 mL, balloon ≧40 mL, and overlapping groups.

Results

The groups included 4645, 4100, 6615, and 1992 women, respectively. In the overlapping group, which included the women in whom delivery was most difficult, the vaginal delivery rate was lower and the intrauterine infection and neonatal mortality rates were higher than those in the dilator group. No difference in the vaginal delivery rate was observed among the dilator, balloon <40 mL, and balloon ≧40 mL groups (74.6%, 72.3%, and 73.8%, respectively; p>0.05). The vaginal instrumental delivery rate was higher in the two-balloon groups than in the dilator group. The volume of intrapartum hemorrhage was lowest in the dilator group. No significant difference in the frequencies of uterine rupture and intrauterine infection were observed among the dilator and two-balloon groups. With regard to neonatal outcomes, the frequency of a low Apgar score was statistically significantly lower in the dilator group than in the two-balloon groups. Moreover, the frequency of neonatal death tended to be lower in the dilator group than in the two-balloon groups.

Conclusion

With regard to cervical ripening for labor induction in nulliparous women at term, the vaginal delivery rate on using a dilator and on using a balloon seems to be equivalent. Concerning maternal complications and neonatal outcomes, cervical ripening with hygroscopic dilators in labor induction might be safer.

Misoprostol Vaginal Insert in Labor Induction: A Cost-Consequences Model for 5 European Countries-An Economic Evaluation Supported with Literature Review and Retrospective Data Collection

Introduction

The present study aimed to assess the costs and consequences of using an innovative medical technology, misoprostol vaginal insert (MVI), for the induction of labor (IOL), in place of alternative technologies used as a standard of care.

Methods

This was a retrospective study on cost and resource utilization connected with economic model development. Target population were women with an unfavorable cervix, from 36 weeks of gestation, for whom IOL is clinically indicated. Data on costs and resources was gathered via a dedicated questionnaire, delivered to clinical experts in five EU countries. The five countries participating in the project and providing completed questionnaires were Austria, Poland, Romania, Russia and Slovakia. A targeted literature review in Medline and Cochrane was conducted to identify randomized clinical trials meeting inclusion criteria and to obtain relative effectiveness data on MVI and the alternative technologies. A hospital perspective was considered as most relevant for the study. The economic model was developed to connect data on clinical effectiveness and safety from randomized clinical trials with real life data from local clinical practice.

Results

The use of MVI in most scenarios was related to a reduced consumption of hospital staff time and reduced length of patients’ stay in hospital wards, leading to lower total costs with MVI when compared to local comparators.

Conclusions

IOL with the use of MVI generated savings from a hospital perspective in most countries and scenarios, in comparison to alternative technologies.

Funding

Sponsorship, article processing charges, and the open access charge for this study were funded by Ferring Pharmaceuticals Poland.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-016-0397-3) contains supplementary material, which is available to authorized users.

Double-balloon catheter versus prostaglandin E2 for cervical ripening and labour induction: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Induction of labour has become an increasingly common procedure. Ripening methods, including mechanical devices and pharmacological agents, improve the success rate of labour induction.

OBJECTIVE

To compare the efficacy and safety of the double-balloon catheter with prostaglandin E2 agents used for labour induction.

SEARCH STRATEGY

We searched electronic sources from MEDLINE, Embase and Web of Science, the Cochrane Library Database of Systematic Reviews, and ClinicalTrials.gov website.

SELECTION CRITERIA

Only randomised controlled trials comparing the PGE2 agents with the double-balloon catheter for cervical ripening and labour induction in women with unfavourable cervices were included in the analysis.

DATA COLLECTION AND ANALYSIS

The main outcomes included the vaginal delivery rate within 24 hours and risk of caesarean section. We calculated relative risks and mean differences using fixed- and random-effects models.

MAIN RESULTS

Nine studies (1866 patients) were included in this systematic review. Both the double-balloon catheter and PGE2 agents were comparable with regard to rate of caesarean section (RR 0.92; 95% CI 0.79, 1.07), vaginal delivery within 24 hours (RR 0.95; 95% CI 0.78, 1.16) and maternal adverse events, but the risk of excessive uterine activity (RR 10.02; 95% CI 3.99, 25.17) and need for neonatal intensive care unit admissions (RR 1.31; 95% CI 1.01, 1.69) were significantly increased in women who received PGE2 agents.

CONCLUSIONS

The double-balloon catheter demonstrated greater safety and cost-effectiveness than PGE2 agents for cervical ripening and labour induction. The efficacy profiles of both methods were similar.

TWEETABLE ABSTRACT

Double-balloon catheter versus prostaglandin E2 for cervical ripening and labour induction.

The Renaissance of Transcervical Balloon Catheters for Cervical Ripening and Labour Induction

Due to rising rates of labour induction in industrialised countries, safe and effective methods of induction have once again become a focus of interest and research. Prostaglandins are effective for cervical ripening and induction of uterine contractions. They do, however, cause overstimulation of the uterus in up to 20 % of cases, sometimes causing changes in fetal heart rate. Transcervical balloon catheters provide an alternative to prostaglandins for labour induction and have been used for this purpose for almost 50 years. This induction method has experienced a recent renaissance in clinical practice that is reflected in an annually rising number of publications on its use. Balloon catheters allow gentle ripening of the cervix without causing uterine overstimulation. The two catheters available are the Foley catheter (off-label use) and the double balloon catheter, which is licensed for use in induction of labour. Both are as effective as prostaglandins, and do not increase the risk of infection to mother or child. Catheter induction also requires less monitoring compared to prostaglandins resulting in improved patient satisfaction. Balloon catheters provide a useful and promising option to achieve vaginal delivery despite failed prostaglandin induction. Intravenous oxytocin is nevertheless required in up to 85 % of cases for adequate induction/augmentation of contractions. Balloon catheters, vaginal PGE₂ and misoprostol are equally effective in the context of an unripe/unfavourable cervix, the rate of uterine hyperstimulation being significantly lower, and the need for oxytocin significantly higher for catheters. Balloon catheters are increasingly being used in combination or sequentially with oral/vaginal misoprostol, although there is currently inadequate published data on the subject. International guidelines recommend the use of balloon catheters for labour induction with an unripe cervix (also following previous caesarean section) as an alternative to prostaglandins, particularly when these are not available or are contraindicated.

Other mechanical methods for pre-induction cervical ripening

Pre-induction cervical ripening is an important part of the labor induction process in women with an unfavorable cervix. This can be achieved either by pharmacologic or mechanical methods of cervical ripening. While the Foley catheter is the most commonly used mechanical method for labor induction, other mechanical methods are also available. This article reviews the safety profiles of osmotic dilators, extra-amniotic saline infusion, double-balloon catheters, and also compares their efficacy to that of other mechanical and pharmacologic cervical ripening methods. While mechanical methods have been shown to be safe and effective for cervical ripening, none of these alternatives has been shown to be superior to the Foley catheter.

Cervical ripening with the balloon catheter and the risk of subsequent preterm birth

OBJECTIVE

To examine the risk of subsequent preterm birth after cervical ripening using a balloon catheter.

STUDY DESIGN

A retrospective study was held at a university teaching hospital between January 2007 and June 2013. The study group included women who underwent cervical ripening using a balloon (single or double) catheter in the previous pregnancy followed by a subsequent singleton delivery (balloon catheter group). Two control groups were included. The first was similar to the study group except that ripening was achieved in the previous pregnancy with vaginal prostaglandin E2 (PGE2 group). The second control group had a previous pregnancy that resulted in spontaneous onset of labor at term (unexposed group). The primary outcome was the incidence of spontaneous preterm birth (before 37 weeks) in the index pregnancy.

RESULT

Overall, 558 women were included; each group consisted of 186 women. The incidence of spontaneous preterm birth in the index pregnancy did not differ between the groups (0.5, 1.6 and 2.7% in the balloon catheter, PGE2 and in the unexposed groups, respectively, P=0.31). Among the balloon catheter group, 58 (31.2%) women had the ripening performed with a single-balloon catheter and 128 (68.8%) women with a double-balloon catheter. The rate of the spontaneous preterm birth in the index pregnancy did not differ between the two groups (P=1.0).

CONCLUSION

Cervical ripening with a balloon catheter does not increase the rate of subsequent spontaneous preterm birth.

Controlled-release dinoprostone insert versus Foley catheter for labor induction: a meta-analysis

OBJECTIVE

To compare the effectiveness and safety of controlled-release dinoprostone insert with Foley catheter balloon for cervical ripening and labor induction.

METHODS

PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and China Knowledge Resource Integrated Database were searched. Only randomized controlled trials comparing controlled-release dinoprostone insert with Foley catheter balloon were included. Risk ratio (RR) or mean difference (MD) with 95% confidence interval (CI) was calculated.

RESULTS

Six studies were included with 731 women received dinoprostone insert and 722 Foley catheter. Time from induction to delivery was significantly shortened in dinoprostone insert group compared to Foley catheter group (MD 5.73 h, 95% CI 1.26-10.20). There were no significant differences in vaginal delivery within 24 h (RR 0.75, 95% CI 0.43-1.30) or cesarean section (RR 0.94, 95% CI 0.80-1.12) between two ripening methods. Dinoprostone insert was related with increased rate of excessive uterine contraction (RR 0.07, 95% CI 0.03-0.19), but less oxytocin use (RR 1.86, 95% CI 1.25-2.77) when compared with Foley catheter.

CONCLUSIONS

Induction of labor with controlled-release dinoprostone insert seems to be more effective than Foley catheter. However, the former method causes excessive uterine contraction more frequently.

Direct electrical stimulation softens the cervix in pregnant and nonpregnant rats

OBJECTIVE

The objective of the study was to determine the effects of electrical stimulation (ES) on cervical ripening in pregnant and nonpregnant rats.

STUDY DESIGN

Timed pregnant and nonpregnant Sprague-Dawley rats (n = 6-7/group) were used. Cervical ES for pregnant rats was performed in vivo on day 15 of gestation by inserting an electrical probe into the vagina in contact with the cervix. Parameters of ES varied from 0.1 to 0.2 mA, 10 pulses per second, 20 milliseconds pulse duration, and repeating pulses for 15, 30, 60, and 120 minutes for pregnant ES groups and similar times for sham control groups with electrode but without ES. Nonpregnant ES groups were stimulated with only 0.2 mA for 30 minutes. Cervical collagen was measured in controls and following ES at various times using light-induced fluorescence (LIF) of collagen. Photographs were taken following ES, and some rats were killed, the cervices were isolated, and cervical extensibility was estimated.

RESULTS

LIF values of pregnant rats are significantly lower (P < .001) and extensibility greater (P < .05) in the ES treatment groups compared with the control groups on days 16 and 17 of pregnancy. Similarly LIF is lower (P < .05) and extensibility values greater (P < .05) in nonpregnant rats treated with ES. No adverse effects, including altered delivery time, pup weights, or damage to cervix, were produced by low current levels of ES needed to soften the cervix.

CONCLUSION

The following conclusions were reached: (1) application of ES rapidly produces softening and ripening of the cervix in pregnant and nonpregnant rats; (2) ES treatment does not produce early delivery; (3) the exact mechanism for ES ripening is not yet known; and (4) ES might be used clinically to ripen the cervix when needed.

[Cervical ripening: is there an advantage for a double-balloon device in labor induction?]

OBJECTIVES

To compare efficiency of a double-balloon to vaginal prostaglandins for cervical ripening in patients with unfavourable cervix.

PATIENTS AND METHODS

Fifty patients induced with a double-balloon were compared to 50 patients receiving vaginal prostaglandins. Matching criteria were age, parity, history of uterine scar, gestational age and Bishop score. The primary outcome was failure induction. Secondary outcomes included improvement in Bishop score, ripening-to-delivery interval, caesarean section rate, maternal and neonatal morbidity.

RESULTS

Risk of failed induction (16% in the double-balloon group vs. 14% in the prostaglandins group) and caesarean section rate (28% vs. 36%) were similar in the two groups. The proportion of favourable cervix and the time to obtain a better Bishop score were similar with the two methods. Maximal pain score during cervical ripening was significantly lower in the double-balloon group (P<0.001). Ripening-to-delivery interval (30.4 h ± 15.6h vs. 28.9 h ± 20.5h) was not different between the two groups. There was no difference about maternal and neonatal outcomes.

DISCUSSION AND CONCLUSION

The double-balloon was as efficient as vaginal prostaglandins. The ripening-to-delivery interval was not different between the two groups. The main advantage of this device could be a better tolerance favourishing patient satisfaction.

Trans-cervical double balloon catheter with and without extra-amniotic saline infusion for cervical ripening: a prospective quasi-randomized trial

OBJECTIVE

To compare the efficacy and safety of the trans-cervical double balloon catheter with and without extra-amniotic saline infusion (EASI) for cervical ripening.

METHODS

This is a secondary analysis of a prospective randomized study conducted between November 2007 and January 2011 evaluating different ripening methods. Women presenting for labor induction were assigned to receive the double balloon catheter with (study group) or without EASI (control group). Outcomes included time from device insertion to delivery, cesarean section rates, and adverse events.

RESULTS

One hundred and sixty women completed the study. Cesarean section rate (8.3% in study group, versus 20% in controls p = 0.07) and ripening success were comparable between the groups. Catheter insertion to delivery interval was significantly shorter and spontaneous catheter expulsion rate was significantly higher in the study group (14:19 hours versus 20:45 hours, p < 0.001, and 68.5% versus 51%, p = 0.04, respectively). Hospitalization length was significantly shorter in the study arm. There were no differences in other outcomes evaluated. A multivariable analysis found the EASI to be an independent predictor of a shorter insertion to delivery interval.

CONCLUSIONS

The addition of EASI to the double balloon catheter for cervical ripening results in a shorter labor induction process without compromising its safety.