Intracervical Foley catheter balloon vs. prostaglandin in preinduction cervical ripening

Which approach is better for labor induction: simultaneous or sequential administration of oxytocin and intrauterine balloon-a systematic review and a meta-analysis

OBJECTIVE

To compare the efficacy of simultaneous and sequential administration of oxytocin and intrauterine balloons in labor induction.

METHODS

The databases of Cochrane Library, Web of Science, PubMed, ClinicalTrials.gov, and Embase were thoroughly searched from their inception to November 2023. Randomized controlled trials (RCTs) investigating the simultaneous and sequential use of oxytocin and intrauterine balloons for labor induction in pregnancy were included. The meta-analysis was performed using RevMan 5.3 statistical software. Heterogeneity among the selected studies was evaluated using the I2 statistic. Dichotomous outcomes were estimated using relative risk (RR) with corresponding 95% confidence intervals (CI), while continuous outcomes were measured as the mean difference (MD).

RESULTS

A total of eight studies, involving a total of 1,315 nulliparous and multiparous women with an unfavorable cervix, were included in the systematic review. Moreover, a subgroup analysis was conducted, separately evaluating nulliparous and multiparous women. Compared with the sequential groups, simultaneous use of oxytocin and intrauterine balloons resulted in a significantly higher rate of delivery within 24h in nulliparas (RR = 1.30, 95%CI:1.04, 1.63, p = 0.02), a higher rate of vaginal delivery within 24h in multiparas (RR = 1.32, 95%CI:1.15,1.51, p < 0.00001), a superior rate of delivery within 12h and a shorter time to delivery in both nulliparas and multiparas. No statistically significant differences were observed in cesarean delivery and maternal and neonatal adverse outcomes between the sequential and simultaneous groups.

CONCLUSIONS

These findings provide support for the simultaneous use of intrauterine balloons and oxytocin during labor induction in nulliparous women. Additionally, this approach may also prove beneficial for multiparas.

Outpatient cervical ripening with balloon catheters: A Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

One in four labors are induced. The process of cervical ripening can be lengthy and pre-labor hospitalization is required. Outpatient cervical ripening can be an attractive alternative.

OBJECTIVES

To evaluate the efficacy and safety of outpatient cervical ripening with a balloon catheter compared with inpatient balloon catheter or prostaglandin E2 (PGE2).

SEARCH STRATEGY

The PubMed, MEDLINE, Embase, ClinicalTrials.gov, and Cochrane Library databases were searched from their inception to October 15, 2022.

SELECTION CRITERIA

Randomized controlled trials comparing the outpatient balloon catheter with inpatient balloon catheter or inpatient PGE2 for term cervical ripening.

DATA COLLECTION AND ANALYSIS

Bayesian network meta-analysis was performed. The primary outcome was the cesarean delivery rate. The secondary outcomes included instrumental delivery, the time from intervention-to-birth, oxytocin augmentation, total hospital duration, and maternal/neonatal adverse events.

MAIN RESULTS

Twenty-nine randomized controlled trials with a total of 6004 participants were identified. No difference in the cesarean delivery rate was revealed among the three interventions. Compared with inpatient balloon catheter, outpatient balloon catheter had shorter total hospital duration (mean difference -8.58, 95% confidence interval -17.02 to -1.10). No differences were revealed in the time from intervention-to-birth, instrumental delivery, postpartum hemorrhage, 5-min Apgar score less than 7, umbilical cord arterial pH less than 7.1, and neonatal intensive care unit admission among the three interventions.

CONCLUSIONS

Outpatient balloon catheter in low-risk term pregnancies is an available option that could be considered for cervical ripening. The safety and effectiveness are comparable to inpatient cervical ripening methods.

[Prostaglandins or cervical balloon for the induction of labor for cervical ripening: A literature review]

OBJECTIVE

Induction of labor in France concerns one birth out of four with 70% of induction starting by cervical ripening, either with a pharmacological (prostaglandins) or a mechanical (balloon) method. This review aims to compare these two methods within current knowledge, using the PRISMA methodology.

METHODS

Trials comparing these two methods, published or unpublished up to July 2023, in French or English were searched for in the PubMed, Cochrane Library and ClinicalTrial.govs datasets. Fifty articles including 10,689 women were selected. The outcomes of interest were those from the Core Outcome Set for trails on Induction of Labour (COSIOL) list: mode of delivery, time from induction-to-birth, maternal and neonatal morbidity, and maternal satisfaction.

RESULT

No differences were observed between the two methods for the mode of delivery or neonatal and maternal morbidity. The time from induction-to-birth was longer for mechanical methods. Those were also associated with a greater need for oxytocin, less uterine hyperstimulation and less instrumental deliveries. Maternal satisfaction was assessed in only nine trials using various scales which made the interpretation of maternal satisfaction.

CONCLUSION

The efficacy of these two induction methods is similar for vaginal delivery, but it remains to be seen which one best meets women's satisfaction criteria.

Efficacy of pharmacological and mechanical cervical priming methods for induction of labour and their applicability for outpatient management: A systematic review of randomised controlled trials

BACKGROUND

A systematic review to determine the efficacy and safety of prostaglandins (PG) and Foley catheter (FC) for cervical priming in the outpatient setting. Various methods are available to achieve cervical ripening prior to induction of labour (IOL). In this systematic review, we will report the literature to date, and investigate the efficacy and safety of using the Foley catheter balloon or prostaglandins for cervical ripening, comparing both methods with each other, and discuss the implications of these findings for midwifery led units.

METHODS

English peer-reviewed journals were systematically searched in the databases PubMed, MEDLINE, EMCARE, EMBASE and CINAHL, for studies investigating cervical ripening using the FC or PGs. Additional randomised controlled trials (RCTs) and non-RCTs were identified by a manual search. Search terms included: cervix dilatation effacement, cervix ripening, outpatient, ambulatory care, obstetric patients, pharmacological preparations, and Foley catheter. Only RCTs of FC versus PG or either intervention versus placebo or intervention in the in-patient Vs. outpatient setting were included. 15 RCTs were included.

RESULTS

The results of this review show that both FC and PG analogues are equally effective cervical ripening agents. When compared to FC, PGs lead to a reduced requirement for oxytocin augmentation and a shorter intervention to delivery interval. However, PG use is also associated with an increased risk of hyperstimulation, cardiotocographic monitoring abnormalities and negative neonatal outcomes.

CONCLUSIONS

FC cervical ripening is an effective method of outpatient cervical priming, which is safe, acceptable, and cost-effective and thus has a potential role in both resource-rich and resource-poor countries. With appropriate dosing, some PG analogues also appear to offer similar 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.

[Retrospective comparison of effectiveness of balloon catheter versus dinoprostone for cervical ripening]

OBJECTIVE

To compare the effectiveness and the safety of cervical ripening between two methods: the Cook double balloon catheter and the dinoprostone pessary (Propess 10mg).

METHODS

We performed a retrospective comparative study in a French maternity. We analyzed 404 women with induction of labour after 37 gestational weeks, with singleton cephalic live fetus, unscarred uterus, unruptured membranes, and Bishop score<6. The primary endpoint was the time between the start of the ripening and the delivery. Secondary endpoints include effectiveness and safety outcomes of the methods.

RESULTS

Compared to dinoprostone pessary, the balloon catheter was associated with a longer time to delivery (34.4±16.5 vs 25.5±15.3h; P<0.001). This difference is found in both primiparous and multiparous women. Balloon catheter is also associated with a smaller improvement of the Bishop score (2.5±2.1 vs 4.2±2.9 Bishop's points; P<0.001) and more failure to achieve delivery in 24h (32.3% vs 56.7%; P<0.001). There was no difference in mother and fetal safety.

CONCLUSION

In this retrospective study, cervical ripening using balloon catheter seems to lengthen the induction of labour. No difference in safety outcomes with dinoprostone was found.

Comparing Foley Catheter to Prostaglandins for Cervical Ripening in Multiparous Women

OBJECTIVE

This study sought to test the hypothesis that among multiparous women requiring cervical ripening, mechanical ripening with a Foley catheter is more effective than prostaglandin preparations.

METHODS

This was a retrospective analysis of multiparous women with a singleton gestation who required cervical ripening in a single tertiary center from 2014 to 2019. Women who underwent cervical ripening with a Foley catheter (Foley group) were compared with women who underwent cervical ripening using a controlled-release dinoprostone vaginal insert (PGE₂-CR group) or dinoprostone vaginal gel (PGE₂-gel group). The primary outcome was the ripening-to-delivery interval.

RESULTS

A total of 229 women met the study criteria (Foley group: 95; PGE₂-CR group: 83; PGE₂-gel group: 51). Women in the Foley group had a significantly shorter ripening-to-delivery interval compared with women in the PGE₂-CR group (16.2 ± 9.2 hours vs. 27.0 ± 14.8 hours; P < 0.001) and were more likely to deliver within 12 hours (47.4% vs. 12.0%; P < 0.001; adjusted relative risk [aRR] 3.87; 95% confidence interval [CI] 2.07-7.26) and within 24 hours (78.9% vs. 49.4%; P < 0.001; aRR 1.61; 95% CI 1.26-2.06). Women in the Foley group were also less likely to require a second ripening method compared with women in the PGE₂-CR group (1.1% vs. 8.4%; P = 0.018; aRR 7.26; 95% CI 2.99-17.62). These differences were not observed when comparing the Foley and the PGE₂-gel groups. The cesarean section rate was similar among the Foley group (9.5%), PGE₂-CR group (9.6%; P = 0.970), and PGE₂-gel group (11.8%; P = 0.664).

CONCLUSION

In multiparous women requiring cervical ripening, all methods of cervical ripening have a similar success rate. However, the use of a PGE₂-CR insert is associated with a considerably longer interval to delivery compared with a Foley catheter or PGE₂ gel.

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.

Intracervical Foley catheter balloon versus dinoprostone insert for induction cervical ripening: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Successful labor induction depends on the cervical status at the time of induction. Currently, both a Foley catheter and a dinoprostone insert are used for effective cervical ripening. This study compared the efficacy and safety of the intracervical Foley catheter and dinoprostone insert for cervical ripening to achieve successful labor induction.

METHODS

PubMed, Embase, and the Cochrane Library were searched from January 2000 to February 2017 for relevant articles. Only published randomized, controlled trials comparing the dinoprostone insert with the Foley catheter were included.

RESULTS

Eight trials including 1191 women who received the intracervical Foley catheter balloon and 1199 who received the dinoprostone insert were used for this study. There was no significant difference between the 2 groups regarding the induction-to-delivery (I-D) interval in a random effect model (mean difference, 0.71 hours; 95% confidence interval [CI], -2.50 to 3.91; P = .67). The highly significant heterogeneity (I = 97%) could be explained by the subgroup analysis of the type of Foley catheter and balloon volume. There was no significant difference between the 2 methods regarding the cesarean delivery rate (relative risk, 0.91; 95% CI, 0.78-1.07; P = .24), Apgar score, or side effects, including maternal infection rate, postpartum hemorrhage, and hyperstimulation. No obvious publication bias was found.

CONCLUSIONS

According to the cesarean delivery rate, the intracervical Foley catheter balloon was as efficient as the dinoprostone insert. A moderate balloon volume (30 mL) and higher dose of dinoprostone (≥6 mg) were related to shorter I-D intervals. Additionally, there was no significant difference between the two methods regarding maternal or neonatal safety.

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.

Risk of maternal, fetal and neonatal complications associated with the use of the transcervical balloon catheter in induction of labour: A systematic review

Induction of labour is one of the most frequently applied obstetrical interventions globally. Many studies have compared the use of balloon catheters with pharmacological agents. Although the safety of the balloon catheter is often mentioned, little has been written about the total spectrum of maternal and fetal morbidity associated with induction of labour using a balloon catheter. We evaluated the safety of labour induction with a transcervical balloon catheter by conducting a literature review with pooled risk assessments of the maternal, fetal and neonatal morbidity. We searched Medline, EMBASE and CINAHL as well as the Cochrane database using the Keywords 'induction of labour', 'cervical ripening', 'transcervical balloon', 'balloon catheter' and 'Foley balloon'. We did not use language or date restrictions. Randomized and quasi-randomized controlled trials as well as observational studies that contained original data on occurrence of maternal, fetal or neonatal morbidity during induction of labour with the balloon catheter were included. Studies were excluded if the balloon catheter was used concurrently with oxytocin and concurrently or consecutively with misoprostol, dinoprostone or extra-amniotic saline infusion. Study selection and quality assessment was performed by two authors independently using a standardized critical appraisal instrument. Outcomes were reported as weighted mean rates. We detected 84 articles reporting on 13,791 women. The overall risk of developing intrapartum maternal infection was 11.3% (912 of 8079 women), 3.3% (151 of 4538 women) for postpartum maternal infection and 4.6% (203 of 4460 women) for neonatal infection. Uterine hypercontractility occurred in 2.7% (148 of 5439) of the women. Uterine rupture after previous caesarean section occurred in 1.9% of women (26 of 1373), while other major maternal complications had an occurrence rate of <1%. The risk for developing minor maternal complications was <2%. The risk of developing a non-reassuring fetal heart rate was 10.8% (793 of 7336 women), 10.1% (507 of 5008 women) for fetal distress and 14.0% (460 of 3295 women) for meconium stained liquor. Neonatal death occurred in 0.29% (6 of 2058) of the deliveries and NICU admission in 7.2% (650 of 9065 deliveries). This review shows that labour induction with a balloon catheter is a safe intervention, with intrapartum maternal infection being the only reasonable risk above 10%.

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.

Foley catheter versus vaginal prostaglandin E2 gel for induction of labour at term (PROBAAT trial): an open-label, randomised controlled trial

BACKGROUND

Induction of labour is a common obstetric procedure. Both mechanical (eg, Foley catheters) and pharmacological methods (eg, prostaglandins) are used for induction of labour in women with an unfavourable cervix. We aimed to compare the effectiveness and safety of induction of labour with a Foley catheter with induction with vaginal prostaglandin E2 gel.

METHODS

We did an open-label, randomised controlled trial in 12 hospitals in the Netherlands between Feb 10, 2009, and May 17, 2010. We enrolled women with a term singleton pregnancy in cephalic presentation, intact membranes, an unfavourable cervix, an indication for induction of labour, and no prior caesarean section. Participants were randomly allocated by an online randomisation system to induction of labour with a 30 mL Foley catheter or vaginal prostaglandin E2 gel (1:1 ratio). Because of the nature of the intervention this study was not blinded. The primary outcome was caesarean section rate. Secondary outcomes were maternal and neonatal morbidity and time from intervention to birth. All analyses were done on an intention-to-treat basis. We also did a meta-analysis that included our trial. The trial was registered with the Dutch trial registry, number NTR 1646.

FINDINGS

824 women were allocated to induction of labour with a Foley catheter (n=412) or vaginal prostaglandin E2 gel (n=412). Caesarean section rates were much the same between the two groups (23%vs 20%, risk ratio [RR] 1·13, 95% CI 0·87-1·47). A meta-analysis including our trial data confirmed that a Foley catheter did not reduce caesarean section rates. We recorded two serious maternal adverse events, both in the prostaglandin group: one uterine perforation and one uterine rupture.

INTERPRETATION

In women with an unfavourable cervix at term, induction of labour with a Foley catheter is similar to induction of labour with prostaglandin E2 gel, with fewer maternal and neonatal side-effects.

FUNDING

None.

Is transcervical Foley catheter actually slower than prostaglandins in ripening the cervix? A randomized study

OBJECTIVE

The purpose of this study was to determine whether the maximum time for cervical ripening (from 24-12 hours) would influence the efficacy of a transcervical Foley catheter and to compare efficacy to that of a prostaglandin E(2) vaginal insert.

STUDY DESIGN

Three hundred ninety-seven women were assigned randomly to (1) Foley catheter left in place for a maximum of 24 hours, (2) Foley catheter left in place for a maximum of 12 hours, or (3) prostaglandin E(2) controlled-release vaginal insert. Primary outcome was vaginal delivery within 24 hours.

RESULTS

There were no differences in vaginal delivery rates. The proportion of women who achieved vaginal delivery in 24 hours was lower in the 24-hour Foley catheter group than in the other 2 groups (24-hour Foley catheter, 21.0%; 12-hour Foley catheter, 59.8%; vaginal prostaglandin E(2), 48.5%; P < .0001).

CONCLUSION

Cutting the ripening time with a Foley catheter by one-half increases the proportion of women who deliver vaginally within 24 hours and yields efficacy similar to that of prostaglandin E(2) vaginal insert.

Foley catheter balloon vs locally applied prostaglandins for cervical ripening and labor induction: a systematic review and metaanalysis

We performed a metaanalysis of publications comparing the efficacy and safety of cervical ripening and labor induction by Foley catheter balloon (FCB) vs locally applied prostaglandins (LAPG) in the third trimester of pregnancy. Twenty-seven randomized controlled trials (1966-2008; 3532 participants) were selected from MEDLINE, EMBASE, and CENTRAL searches. There was no significant difference between FCB and LAPG in cesarean delivery rates. LAPG had a significantly increased risk of excessive uterine activity (P = .001). FCB had a significantly higher risk of oxytocin induction/augmentation during labor (P = .0002). Cervical prostaglandin-E2 was less effective (P = .04), and vaginal prostaglandin-E1 bore a significantly higher risk of excessive uterine activity (P < .0001) and meconium staining (P = .04). We concluded that FCB and LAPG result in similar cesarean delivery rates, that FCB bears a higher risk of oxytocin use for labor induction and/or augmentation, and that LAPG carries a higher risk of contraction abnormalities.

Reducing stillbirths: interventions during labour

BACKGROUND

Approximately one million stillbirths occur annually during labour; most of these stillbirths occur in low and middle-income countries and are associated with absent, inadequate, or delayed obstetric care. The low proportion of intrapartum stillbirths in high-income countries suggests that intrapartum stillbirths are largely preventable with quality intrapartum care, including prompt recognition and management of intrapartum complications. The evidence for impact of intrapartum interventions on stillbirth and perinatal mortality outcomes has not yet been systematically examined.

METHODS

We undertook a systematic review of the published literature, searching PubMed and the Cochrane Library, of trials and reviews (N = 230) that reported stillbirth or perinatal mortality outcomes for eight interventions delivered during labour. Where eligible randomised controlled trials had been published after the most recent Cochrane review on any given intervention, we incorporated these new trial findings into a new meta-analysis with the Cochrane included studies.

RESULTS

We found a paucity of studies reporting statistically significant evidence of impact on perinatal mortality, especially on stillbirths. Available evidence suggests that operative delivery, especially Caesarean section, contributes to decreased stillbirth rates. Induction of labour rather than expectant management in post-term pregnancies showed strong evidence of impact, though there was not enough evidence to suggest superior safety for the fetus of any given drug or drugs for induction of labour. Planned Caesarean section for term breech presentation has been shown in a large randomised trial to reduce stillbirths, but the feasibility and consequences of implementing this intervention routinely in low-/middle-income countries add caveats to recommending its use. Magnesium sulphate for pre-eclampsia and eclampsia is effective in preventing eclamptic seizures, but studies have not demonstrated impact on perinatal mortality. There was limited evidence of impact for maternal hyperoxygenation, and concerns remain about maternal safety. Transcervical amnioinfusion for meconium staining appears promising for low/middle income-country application according to the findings of many small studies, but a large randomised trial of the intervention had no significant impact on perinatal mortality, suggesting that further studies are needed.

CONCLUSION

Although the global appeal to prioritise access to emergency obstetric care, especially vacuum extraction and Caesarean section, rests largely on observational and population-based data, these interventions are clearly life-saving in many cases of fetal compromise. Safe, comprehensive essential and emergency obstetric care is particularly needed, and can make the greatest impact on stillbirth rates, in low-resource settings. Other advanced interventions such as amnioinfusion and hyperoxygenation may reduce perinatal mortality, but concerns about safety and effectiveness require further study before they can be routinely included in programs.

A randomised controlled trial of intravaginal dinoprostone, intravaginal misoprostol and transcervical balloon catheter for labour induction

OBJECTIVE

To compare the efficacy and safety of induction of labour by vaginal application of dinoprostone or misoprostol or transcervical insertion of a balloon (Bard) catheter.

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level Swedish hospital.

POPULATION

A total of 592 women who had undergone full-term pregnancies, not previously been subjected to a caesarean section, and required induction of labour for common, routine indications.

METHODS

Women were randomly assigned to induction of labour using intravaginal dinoprostone (2 mg once every 6 hours) or misoprostol (25 micrograms once every 4 hours) or a transcervical balloon catheter.

MAIN OUTCOME MEASURES

The time interval between induction to delivery in general and vaginal delivery in particular, the mode of delivery, maternal and neonatal parameters of outcome.

RESULTS

Of the 588 subjects included in the final intention-to-treat analysis, 191 were assigned to treatment with dinoprostone, 199 with misoprostol and 198 with the balloon catheter. The shortest mean induction-to-delivery interval was obtained with the catheter (12.9 hours versus 16.8 and 17.3 hours for dinoprostone and misoprostol, respectively). The efficacies of the two prostaglandins were similar. The maternal and neonatal outcomes associated with each of the three procedures were similar.

CONCLUSIONS

Induction of labour with a transcervical balloon catheter is effective and safe and can be recommended as the first choice. The two prostaglandins, dinoprostone and misoprostol, were shown to be equally effective and safe, while misoprostol costs significantly less and is easier to store.

Do mechanical methods of cervical ripening increase infectious morbidity? A systematic review

The purpose of this study was to review systematically randomized controlled trials that were associated with cervical ripening. We identified randomized controlled trials that compared the use of Foley catheter, with or without extraamniotic saline solution infusion, Laminaria, or hygroscopic dilators for cervical ripening or induction with pharmacologic agents or placebo. Randomized controlled trials that evaluated maternal or neonatal infection were selected. The outcomes that were assessed were maternal and neonatal infection, chorioamnionitis, and endomyometritis. Thirty studies met inclusion criteria. Compared with the use of pharmacologic methods alone, patients who underwent cervical ripening with mechanical agents had a significantly higher rate of maternal infection rates. Similar results were noted for patients who underwent ripening with Foley catheter alone in comparison with pharmacologic agents. No difference was noted in maternal infection rates for patients who underwent ripening with extraamniotic saline solution infusion, Laminaria, or hygroscopic dilators. Compared with the use of pharmacologic agents alone, maternal and neonatal infectious morbidity appears to be increased when mechanical agents are used for cervical ripening.

Cervical ripening with the Foley catheter

OBJECTIVE

To evaluate maternal and neonatal outcomes in a large series of patients undergoing cervical ripening with a Foley catheter.

METHODS

The database of the Labor and Delivery Unit of the University of a teaching hospital in Italy was used to identify consecutive patients with a Bishop score (BS) of 4 or less who underwent pre-induction cervical ripening with a Foley catheter. The main outcome measures were clinical chorioamnionitis, endometritis, and suspected and culture-proven neonatal sepsis.

RESULTS

Of 602 women undergoing cervical ripening with a Foley catheter, 160 (26.6%) went into active labor without additional interventions. Oxytocin was administered immediately after removal of the Foley catheter in 188 (31.2%) of the women, and 254 (42.2%) required an application of prostaglandin E2 vaginal gel. The cesarean delivery rate was 25.6%. The median time to delivery was 1469 min (range, 94-3350 min). Of the women who gave birth vaginally, 225 (50.2%) were delivered within 24 h. Clinical chorioamnionitis and postpartum endometritis occurred in 3 (0.5%) and 6 (1.0%) of the women, respectively. Neonatal sepsis was suspected in 4 (0.7%) of the newborns but blood culture results were negative in all cases.

CONCLUSION

Transcervical use of the Foley catheter is safe for pre-induction cervical ripening, and the associated risk of maternal or perinatal infections is negligible.

Mechanical Methods of Cervical Ripening and Labor Induction

This article reviews the safety and efficacy of mechanical agents for cervical ripening. Hygroscopic dilators, balloon catheters, and devices designed for cervical ripening have all been shown to be safe and effective for cervical ripening. Mechanical agents are as efficacious as other agents for cervical ripening. However, there is no method that has been conclusively shown to improve mode of delivery or perinatal outcome. The advantages of preinduction cervical ripening with mechanical devices include low cost, low incidence of systemic side effects, and low risk of uterine hyperstimulation.

Hyaluronidase versus Foley catheter for cervical ripening in high-risk term and post term pregnancies

OBJECTIVE

To evaluate the effectiveness and safety of Foley catheter and hyaluronidase for cervical ripening.

METHOD

Randomized controlled trial where 140 pregnant women, with gestational age > or = 37 weeks, indication for labor induction and an unripe cervix, were enrolled, allocated in two groups according to the method of cervical ripening before labor induction. Statistical analysis used Student's t-test, Mann-Whitney, Chi-square test, survival analysis, risk ratios and number needed to treat.

RESULTS

Time of induction, dose of oxytocin and mode of delivery had better results in the Foley catheter group. Comfort with the method was higher in the hyaluronidase group.

CONCLUSIONS

Both methods were effective and safe for cervical ripening. The Foley catheter group experienced a shorter period of induction, required a lower dose of oxytocin and had higher vaginal delivery rates, while the women who used hyaluronidase declared greater comfort with the method.