Cervical ripening and induction of labor with misoprostol, dinoprostone gel, and a Foley catheter: a randomized trial of 3 techniques

Effectiveness of Single Fetal Membrane Sweeping in Reducing Elective Labor Induction for Postdate Pregnancies (38+0 to 40+6 Weeks): A Randomized Controlled Trial

BACKGROUND

 Postdate pregnancy is characterized by a heightened risk for both maternal and perinatal complications. Owing to the risks, clinicians frequently turn to elective labor induction as a management strategy for postdate pregnancies. However, patients are increasingly informed and apprehensive about this approach and its associated risks. This has prompted a search for alternative management methods that may encourage spontaneous labor in pregnant women. One such approach is the use of fetal membrane sweeping, a method known to increase the likelihood of spontaneous labor onset. Yet, it remains unclear whether a single fetal membrane sweeping procedure can effectively reduce the need for elective labor induction in postdate pregnancies while minimizing risks to both the mother and fetus.

OBJECTIVES

The primary objective of this study was to assess the efficacy of a single fetal membrane sweeping procedure conducted between 38+0 and 40+6 weeks of gestation in reducing the rate of elective labor induction among postdate pregnancies at Central Hospital Benin City, Nigeria. Secondary objectives included evaluating the impact of membrane sweeping on maternal and perinatal outcomes.

METHODOLOGY

This open-label superiority randomized controlled study was carried out from June 2020 to March 2021, following ethical approval from the Hospital Management Board (HMB). One hundred and forty eligible participants, without contraindications to vaginal delivery, were randomly assigned to one of two groups. The first group received a single fetal membrane sweeping procedure between 38+0 and 40+6 weeks of gestation, while the control group underwent vaginal examination only to assess the Bishop score. Participants were monitored until delivery. Data analysis was performed. Results were considered statistically significant at p < 0.05.

RESULTS

The implementation of a single fetal membrane sweeping procedure effectively reduced the incidence of elective labor induction. Specifically, the membrane sweep group exhibited a significantly lower rate of elective labor induction compared to the control group (9.0% vs. 27.1%; p=0.0083). Moreover, a substantial proportion of the treatment group (91.4%) experienced spontaneous labor, while the control group reported a rate of 72.9%. The difference was statistically significant (p=0.0054). Notably, the control group exhibited a significantly longer mean time interval from recruitment to delivery (10.67±3.51 days) than the membrane sweeping group (3.64±4.123 days; p<0.05). Also, postdate women in the membrane sweep group were less likely to require cervical ripening with Foley's catheter than those in the control group (33.3% vs. 100%; RR: 0.33 (0.11-1.03); p=0.0057). Still, maternal satisfaction was significantly higher in the membrane-sweeping group (p<0.01). No significant differences were noted across the groups in maternal and neonatal outcomes.

CONCLUSION

In low-risk term pregnancies, a single fetal membrane sweeping procedure is a superior alternative to no membrane sweeping in reducing the rate of elective labor induction for postdate pregnancies and in shortening the duration of term pregnancy.

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.

Intra-cervical Foley Balloon Catheter Versus Prostaglandins for the Induction of Labour: A Literature Review

Labour induction involves helping a woman to start her labour, before labour begins on its own, for a vaginal birth with the aid of artificial methods, such as medications or other medical techniques. Labour induction is done in cases where extending the pregnancy can threaten the mother or her baby's health, and delivery should result in better outcomes than continuing the pregnancy. Currently, nearly 25% of babies are born by labour induction in economically developed countries. It is often necessary in certain situations to induce labour by using ripening techniques that not only soften the cervix but also make it thin and dilated. Mechanical or pharmacological approaches are used for the artificial induction of labour. Because research articles evaluating the safety and efficacy of various ripening techniques of the cervix vary in terms of their findings, it remains uncertain as to which is the best way to induce labour. In light of this, to find out the most popular interventions for ripening of the cervix during labour induction, we performed a review of the literature that compares the use of a Foley catheter and prostaglandins (misoprostol and dinoprostone). Our findings show that using misoprostol orally is much better than using it vaginally. Foley catheter proved to be the least effective induction technique, despite the fact that it offers the lowest risk.

Comparison of intracervical Foley catheter combined with a single dose of vaginal misoprostol tablet or intracervical dinoprostone gel for cervical ripening: a randomised study

We compared two combined methods for cervical ripening before induction of labour (IOL) Women (n = 150) were randomised into Foley's-misoprostol (n = 75) and Foley's-dinoprostone (n = 75) groups. A single dose of vaginal misoprostol tablet (25 µg) or intracervical dinoprostone gel (0.5 mg) were used alongwith intracervical Foley's. The primary outcome was induction-delivery interval (IDI) and secondary outcomes were change in Bishop's score, oxytocin requirement, caesarean section (CS) rate, chorioamnionitis and neonatal outcome. The mean parity, gestation and indications for IOL were similar in the two groups. The IDI (19 h 37 min and 19 h 20 min; p = .683), cervical ripening time, oxytocin requirement, CS rate (18.7 and 25.4%, p = .322) and neonatal outcome were similar. Hyperstimulation developed in 2.7% women with Foley's-misoprostol and in 1.3% with Foley's-dinoprostone (p = .55). No woman had chorioamnionitis. Thus, these two combined methods of cervical ripening and IOL were observed to be similarly efficacious. A low incidence of hyperstimulation and no chorioamnionitis may be attributed to using a single dose of prostaglandins. Misoprostol may be substituted for dinoprostone in resource limited countries.Impact statementWhat is already known on this subject? Combined methods for cervical ripening (intracervical Foley's plus prostaglandins) before induction of labour (IOL) may be similarly or more efficacious than individual methods. Most studies comparing various combined methods have used repeated doses of prostaglandins. A combined method using repetitive doses of prostaglandins may increase the risk of hyperstimulation and also of infection consequent to repeated vaginal examination to administer prostaglandins. These two concerns may be offset by combining a single dose of prostaglandin with intracervical Foley's catheter.What do the results of this study add? Two combined methods for cervical ripening using a single dose of vaginal misoprostol (25 µg) or intracervical dinoprostone gel (0.5 mg) co-administered with intracervical Foley's catheter were found to be similarly efficacious. The IDI (19 h 37 min and 19 h 20 min; p = .683), cervical ripening time, oxytocin requirement, CS rate (18.7 and 25.4%, p = .322) and neonatal outcome were similar. The incidence of hyperstimulation was low (2.7 and 1.3% with Foley's-misoprostol and Foley's-dinoprostone, respectively) and no woman had chorioamnionitis.What are the implications of these findings for clinical practice and/or further research? Combined methods for cervical ripening using a single dose of prostaglandins (misoprostol or dinoprostone) were observed to be similarly efficacious. Misoprostol is a cheaper alternative to dinoprostone and may be utilised in resource limited countries. These methods may be compared with each other in more number of women in order to identify which combined method is more efficient and safe. Clinical Trials Registry of India: CTRI/2017/12/010738.

Foley catheter and controlled release dinoprostone versus foley catheter labor induction in nulliparas: a randomized trial

PURPOSE

To evaluate Foley catheter and controlled release dinoprostone insert compared to foley catheter alone on induction to delivery interval and maternal satisfaction.

METHODS

A randomized trial was conducted in a university hospital in Malaysia from December 2018 to May 2019. Term nulliparas with unfavorable cervix (Bishop score ≤ 5) scheduled for labor induction were randomized to Foley catheter and controlled release dinoprostone insert simultaneously or Foley catheter alone. Primary outcomes were induction to delivery interval (hours) and maternal satisfaction on birth experience (assessed by 11-point Visual Numerical Rating Scale VNRS 0-10, higher score more satisfied).

RESULTS

Induction to vaginal delivery intervals was mean ± standard deviation 22.5 ± 10.4 vs. 35.1 ± 14.9 h, P =  < 0.001 but maternal satisfaction on birth experience was not significantly different median[interquartile range] VNRS 8[7-9] vs. 8[7-9], P = 0.12 for Foley catheter-controlled-release dinoprostone and Foley catheter alone arms, respectively. Cesarean delivery rates were 35/102(34.3%) vs. 50/101(49.5%), P = 0.02 RR 0.7 95% CI 0.5-0.9 NNTb 6.3 95% CI 3.5-39.4, pain score at 6 h after catheter insertion 5[2-8] vs. 1[1-3], P < 0.001, Bishop score at trial devices removal 9[9-10] vs. 8[7-9], P = 0.001, requirement for oxytocin induction or augmentation 39/102(38.2%) vs. 76/101(75.2%) NNTb 3 95% CI 2.0-4.1, P < 0.001 and amniotomy rates 73/99(73.7%) vs. 81/95(85.3%), P = 0.052 RR 0.9 85% CI 0.8-1.0 in Foley catheter-controlled-release dinoprostone and Foley catheter alone arms respectively.

CONCLUSION

In nulliparas with unripe cervixes at term, combined Foley catheter and controlled release dinoprostone vaginal insert compared to Foley catheter alone reduces the induction to vaginal delivery interval and cesarean delivery rate but satisfaction was not significantly increased.

CLINICAL TRIAL REGISTRATION

ISRCTN2282883, 03/12/2018, "prospectively registered" ( https://doi.org/10.1186/ISRCTN12282883 ).

Labor induction with prostaglandin E1 versus E2: a comparison of outcomes

OBJECTIVE

To compare the peripartum outcomes when labor is induced with prostaglandins E₁ versus E₂.

METHODOLOGY

The Consortium of Safe Labor database was utilized. Women with non-anomalous singletons >24 weeks gestation undergoing induction were analyzed. The primary endpoint was a composite adverse maternal outcome with a composite adverse neonatal outcome as our secondary outcome.

RESULTS

Of the 228,438 births within the database, 8229 (10.8%) met inclusion criteria with 4703 (55.7%) receiving PGE₁, and 3741 (44.3%), PGE₂. The rate of vaginal delivery was similar between both. Composite adverse maternal outcome, was more likely among the prostaglandin E₁: 7.2% vs. 1.5% (aOR 4.20; 95% CI 3.02-5.85); similar trend observed with composite adverse neonatal outcome rates: 4.6% vs. 1.4% (aOR 1.69; 95% CI 1.14-2.50).

CONCLUSION

Utilization of prostaglandin E₁, compared to E_2, was associated with an increased likelihood of adverse maternal and neonatal outcomes.

Foley Bulb Added to an Oral Misoprostol Induction Protocol: A Cluster Randomized Trial

OBJECTIVE

To evaluate whether the induction of labor in term gravid women with cervical dilation 2 cm or less and intact membranes by using oral misoprostol preceded by transcervical Foley bulb placement results in a significantly increased vaginal delivery rate compared with the use of oral misoprostol alone.

METHODS

We randomized the induction method by week of admission to labor and delivery, with each week group described as a cluster in a block randomized design. Women with gestational age of 37 weeks or greater, cervical dilation 2 cm or less, intact membranes, and indication for labor induction were included. Study arms were either 100 micrograms of oral misoprostol after transcervical Foley bulb placement or 100 micrograms of oral misoprostol alone. The primary outcome was vaginal delivery with the first induction attempt. Secondary outcomes included time to delivery, clinical chorioamnionitis (maternal temperature of 38°C or greater during labor with or without fundal tenderness, without other identified cause), cesarean delivery indication, and adverse outcomes. We estimated that a sample size of 1,077 per arm was needed to detect a 5% increase in vaginal delivery rate with a type I error of 5% and power of 80%, accounting for interim analysis and cluster size of 30 inductions per week. This was a pragmatic trial, and analysis was by intention-to-treat.

RESULTS

From January 1, 2018, to May 13, 2019, 1,117 women (34 clusters) were assigned to oral misoprostol plus Foley and 1,110 women (34 clusters) to oral misoprostol alone. Demographic characteristics were similar. Vaginal delivery at the first induction occurred in 78% of the misoprostol plus Foley arm and in 77% of the misoprostol arm (relative risk [RR] 1.00; 95% CI 0.96-1.05; adjusted relative risk [aRR], 1.00; 95% CI 0.95-1.05). Clinical chorioamnionitis occurred in 18% of the misoprostol plus Foley arm and in 14% of the misoprostol arm (RR 1.30; 95% CI 1.07-1.58; aRR 1.30; 95% CI 1.08-1.56). There were no differences in neonatal outcomes.

CONCLUSION

Induction of labor in gravid women at term with intact membranes by using oral misoprostol plus Foley bulb did not result in a higher vaginal delivery rate, but it did result in more clinical chorioamnionitis compared with the use of oral misoprostol alone.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03407625.

Combination of Foley and prostaglandins versus Foley and oxytocin for cervical ripening: a network meta-analysis

BACKGROUND

Trial and meta-analysis data revealed a reduction in time to delivery for Foley and prostaglandins or Foley and oxytocin vs Foley alone. However, there are limited data for the comparison of the 2 combination methods against each other.

OBJECTIVE

This study aimed to determine whether Foley and prostaglandins or Foley and oxytocin decrease the time to vaginal delivery using a network meta-analysis.

STUDY DESIGN

A network meta-analysis (PROSPERO CRD42018081948) was performed comparing Foley and prostaglandins (prostaglandin E1 or prostaglandin E2) vs Foley and oxytocin for cervical ripening. Foley alone and prostaglandins alone were used as nodes for indirect comparison. Database searches were performed from inception to March 2020 with data abstracted from published manuscripts. Eligibility criteria included randomized trials comparing Foley and oxytocin with Foley and prostaglandins (misoprostol or dinoprostone). Trials that compared Foley catheter or prostaglandins with a combination of Foley and prostaglandins or Foley and concurrent oxytocin were also included. Nulliparous and multiparous women were analyzed together. Foley catheters of any catheter material or size and >24 weeks' gestational age with a live fetus were included. Quasi-randomized, cohorts, and other combination methods for cervical ripening were not included. Prostaglandin E1 and prostaglandin E2 combined methods were analyzed separately in a planned subanalysis. The primary outcome was the mean time from induction to vaginal delivery in hours. Secondary outcomes included time from induction to delivery, delivery within 24 hours, cesarean delivery, chorioamnionitis, endometritis, epidural use, tachysystole, postpartum hemorrhage, meconium, neonatal intensive care unit admission, and 5-minute appearance, pulse, grimace, activity, and respiration score of <7. Data were analyzed as a network meta-analysis using multivariate meta-regression.

RESULTS

A total of 30 randomized controlled trials with a total of 6465 women were considered eligible for inclusion in this network meta-analysis. When compared with Foley alone, the use of Foley-oxytocin reduced the time to vaginal delivery by 4.2 hours (mean duration, -4.2 hours; 95% confidence interval, -6.5 to -1.9). Foley-prostaglandins reduced the time to vaginal delivery compared with Foley but did not meet statistical significance (mean duration, -2.9 hours; 95% confidence interval, -5.7 to 0.0; P=.05). When compared head-to-head, there was no difference in the time to vaginal delivery between Foley-prostaglandins and Foley-oxytocin (mean duration, 1.3 hours; 95% confidence interval, -2.0 to 4.7). There was no difference in the rate of cesarean delivery, chorioamnionitis, epidural, tachysystole, postpartum hemorrhage, meconium, neonatal intensive care unit admissions, or 5-minute appearance, pulse, grimace, activity, and respiration score of <7 for Foley-prostaglandins vs Foley-oxytocin, although the rate of endometritis was high for Foley-prostaglandins. In the subanalysis by prostaglandin type, there was no difference in the time to vaginal delivery for Foley-misoprostol vs Foley-dinoprostone vs Foley-oxytocin. However, Foley-dinoprostone had a definite trend toward longer time to all deliveries compared with that of both Foley-misoprostol and Foley-oxytocin (P=.05).

CONCLUSION

Time to vaginal delivery was similar when comparing Foley with combined misoprostol, combined dinoprostone, and combined oxytocin. Dinoprostone comparisons are limited by small sample size but suggest longer time to delivery compared with Foley and misoprostol or oxytocin. No significant differences were observed in maternal or neonatal adverse events except for endometritis, but this was limited by the sample size, varied reporting of studies used in the indirect comparisons, and definitions of infectious morbidity use in the studies.

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.

Comparison of Dinoprostone and Oxytocin for the Induction of Labor in Late-Term Pregnancy and the Rate of Cesarean Section: A Retrospective Study in Ten Centers in South China

Background

Dinoprostone is the recommended primary option for induction of labor (IOL) in late-term pregnancies (LTPs). However, oxytocin is used in developing and rural areas, and studies have supported similar effectiveness for oxytocin and dinoprostone in reducing the rate of cesarean delivery of LTPs with a Bishop’s score of between 4–6. This study aimed to compare dinoprostone and oxytocin for IOL in LTPs and the rate of cesarean section in ten centers in South China.

Material/Methods

A retrospective study included 1,408 women with LTP, with subgroups including a Bishop’s score of 0–3 and 4–6. Rates of cesarean delivery were compared between women given vaginal dinoprostone and intravenous oxytocin for IOL. Secondary outcomes included the duration of labor, and maternal and fetal complications.

Results

Comparison between women who received oxytocin (N=365) and dinoprostone (N=1,043) showed significantly lower rates of cesarean delivery with dinoprostone, but no significant difference between the subgroups with Bishop’s scores of 0–3 and 4–6. The interval between induction to labor and duration of the active phase of labor were significantly reduced in the dinoprostone group with a Bishop’s score of between 4–6.

Conclusions

For LTPs with a Bishop’s score of 0–3, dinoprostone was superior to oxytocin for IOL with a lower rate of cesarean delivery, but both agents had a similar outcome for women with a Bishop’s score of 4–6. These findings may have implications for the choice of agent used in IOL when dinoprostone is unavailable.

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.

Sublingual Misoprostol versus Foley catheter for cervical ripening in women with preeclampsia or gestational hypertension: A randomized control trial

Background

Delivery is the only definite cure for hypertensive disorders. Therefore, cervical ripening and labor induction are important to achieve favorable outcomes.

Objective

This Randomized Control Trial (RCT) is aimed to compare the effects of sublingual misoprostol and Foley catheter in cervical ripening and labor induction among patients with preeclampsia or gestational hypertension.

Materials and Methods

A total number of 144 women with preeclampsia or gestational hypertention with indication of pregnancy termination, who were referred to academic hospitals of the University of Medical Sciences in Mashhad, Iran, between March 2015 and December 2016, were randomly divided into two groups. In group one (n = 72), 25 µg of misoprostol tablet was administrated sublingually every 4 hr up to six doses. In group two (n = 72), a 16F Foley catheter was placed through the internal cervical os, inflated with 60 cc of sterile saline.

Results

There were no significant differences between groups regarding the demographic characteristics, primary bishop score, and pregnancy termination indication. The cervical ripening time (primary outcome) (8.2 vs 14.2 hr, p < 0.00), induction to delivery interval (15.5 vs 19.9 hr, p < 0.00), and vaginal delivery before 24 hr (63.9% vs 40%, p = 0.03) were significantly different between the two groups. There was no significant difference between groups in view of oxytocin requirement (p = 0.12), neonatal Apgar score (p = 0.84), or neonatal intensive care unit admission (p = 78).

Conclusion

This trial showed that the application of sublingual misoprostol, compared to the Foley catheter, can reduce cervical ripening period and other parameters related to the duration of vaginal delivery. This misoprostol regimen showed inconsiderable maternal complications.

Blown out of proportion? Induction Foley balloon ruptures associated with overinflation

BACKGROUND

Larger volume Foley catheters are occasionally used for labor induction. In some instances the balloon is overinflated to obtain this volume. Neither the risk or rate of rupture are known for this practice.

OBJECTIVE

The purpose of this study was to evaluate the use of overinflated Foley catheter balloons and the rate of rupture in prospective trials and to describe rupture events in our institutions.

STUDY DESIGN

Clinical trials and prospective cohorts were identified through a search of MEDLINE from 2000 through May 1, 2017; prospective studies were examined for the use of overinflated Foley catheters. Reports of overinflated balloons were then reviewed in detail to determine if rupture occurred and to record any reported maternal, neonatal, or gynecologic outcomes. Internal reports to the Obstetric Safety Report System were used to describe the local cases at our institutions.

RESULTS

We reviewed 296 abstracts. Seventeen prospective cohorts or randomized trials used larger balloon volumes (≥50 mL), of which 12 abstracts confirmed routine overinflation of the balloon. Within these studies, 19 patients who underwent cervical ripening with overinflated Foley catheters experienced balloon rupture during use. The incidence of rupture in these studies was 0.9%. No adverse maternal or fetal effects were noted. Internal safety reporting yielded an additional case. One gynecologic case was identified internally. The patient had an overinflated Foley catheter balloon used to tamponade excessive uterine bleeding after uterine evacuation. Balloon rupture was noted, and hysteroscopy was needed to remove fragments of the balloon.

CONCLUSION

Overinflation of Foley catheter balloons in obstetric and gynecologic applications may cause rupture. Because of possible underreporting, the extent of complications that may result from balloon rupture is unknown.

Maternal and neonatal outcomes with mechanical cervical dilation plus misoprostol compared to misoprostol alone for cervical ripening; a systematic review of literature and metaanalysis

OBJECTIVE DATA

The aim of the present systematic review was to investigate the efficacy and safety of cervical ripening for the combination of mechanical dilation and misoprostol administration compared with misoprostol alone by evaluating 2 primary outcomes: time to delivery and rate of cesarean delivery.

STUDY

The Medline, EMBASE, and Web-of-Science electronic databases (from conception to end-of-search date December 31, 2018) were searched systematically. Randomized controlled trials that included patients with a singleton viable fetus who underwent induction of labor that required cervical ripening with an unfavorable cervix (Bishop ≤7) were eligible for inclusion.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data were pooled with the use of the random effects and fixed effects model after the assessment for the presence of heterogeneity. Risk of bias for each included study was assessed based on the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Eleven trials met the inclusion criteria and included a total of 922 and 947 subjects in the combination and misoprostol-only groups, respectively. There was no difference in the incidence of cesarean delivery between the 2 groups (relative risk, 0.95; 95% confidence interval, 0.80-1.13). The combination of mechanical dilation and misoprostol resulted in overall shorter time to delivery (mean difference, -3.65 hours; 95% confidence interval, 5.23 to -2.07), shorter time to vaginal delivery (mean difference, -4.53 hours; 95% confidence interval, -5.79 to -3.27), lower risk of neonatal intensive care unit admission (relative risk, 0.71; 95% confidence interval, 0.53-0.96), meconium-stained fluid (relative risk, 0.62; 95% confidence interval, 0.43-0.90), tachysystole with fetal heart trace changes (relative risk, 0.53; 95% confidence interval, 0.30-0.94), and terbutaline use (relative risk, 0.63; 95% confidence interval, 0.47-0.85) compared with the use of misoprostol alone. Risk of endometritis (relative risk, 1.07; 95% confidence interval, 0.43-2.61) and chorioamnionitis (relative risk, 1.58; 95% confidence interval, 0.88-2.84) was comparable between the 2 groups.

CONCLUSION

The combination of mechanical cervical dilation with misoprostol for cervical ripening is associated with a shorter time to delivery, a similar rate of cesarean delivery, and a lower incidence of neonatal intensive care unit admission compared with the use of misoprostol alone.

Misoprostol combined with cervical single or double balloon catheters versus misoprostol alone for labor induction of singleton pregnancies: a meta-analysis of randomized trials

Objective: To compare the effect of misoprostol combined with a cervical single or double-balloon catheter versus misoprostol alone for labor induction of singleton pregnancies with an unfavorable cervix.Methods: Systematic review and meta-analysis of randomized controlled trials (RCTs) regarding the comparison of two schemes for labor induction of singleton cephalic pregnancies with a Bishop score ≤7 and no contraindication for vaginal delivery. Six research databases were searched for articles published in all languages up to 10 May 2018 comparing misoprostol (oral or vaginal) in combination with a cervical placed single or double balloon catheter versus misoprostol treatment alone. Random effects models and inverse variance were used for meta-analyses. Summary measures were mean differences (MDs) and risk ratios (RRs) with 95% confidence interval (CI). Risk of bias was evaluated with the Cochrane tool and publication bias was assessed with Begg's and Egger's tests.Results: Fifteen RCTs reported predefined outcomes. Pooled analyses showed that the combined treatment (misoprostol + catheter) was associated with a shorter induction to delivery time interval (MD = -1.99 hours; 95% CI: -3.42, -0.56); in addition to fewer uterine hyperstimulations (RR = 0.39; 95% CI: 0.23, 0.67) and Neonatal Intensive Care Unit (NICU) admissions (RR = 0.75; 95% CI: 0.58, 0.97) as compared to misoprostol alone. There were no significant differences in RRs for tachysystole, chorioamnionitis, cesarean delivery rate, birthweight, and Apgar score at 5 minutes.Conclusion: The combined use of misoprostol and a cervical balloon catheter reduces the intervention to delivery time interval and number of NICU admissions in women induced with an unfavorable cervix.

Comparative outcome of induced labor by intracervical Foley catheter with misoprostol versus misoprostol alone

Aim: To evaluate the comparative outcome of induced labor by intracervical Foley catheter with misoprostol versus misoprostol alone. Materials & methods: A total of 1306 women were enrolled over 4 years, induced with either intracervical Foley with misoprostol or misoprostol alone and compared in terms of induction-delivery interval, mode of delivery, the presence of uterine tachysystole, postpartum hemorrhage and perinatal outcome. Results: Induction to delivery interval, the duration between induction to active labor was significantly reduced, deliveries within 24 h were significantly higher and the number of misoprostol doses used was significantly less in Foley with misoprostol group. Conclusion: The outcome of combination of intracervical Foley catheter and misoprostol is superior for labor induction, without affecting maternal or perinatal outcome.

Labor Induction Techniques: Which Is the Best?

Induction of labor is a common procedure undertaken whenever the benefits of prompt delivery outweigh the risks of expectant management. Cervical assessment is essential to determine the optimal approach. Indication for induction, clinical presentation and history, safety, cost, and patient preference may factor into the selection of methods. For the unfavorable cervix, several pharmacologic and mechanical methods are available, each with associated advantages and disadvantages. In women with a favorable cervix, combined use of amniotomy and intravenous oxytocin is generally the most effective approach. The goal of labor induction is to ensure the best possible outcome for mother and newborn.

Induction of Labor Using a Foley Catheter or Misoprostol: A Systematic Review and Meta-analysis

Importance

Induction of labor is a widely used obstetric intervention, occurring in one in four pregnancies. When the cervix is unfavorable, still many different induction methods are used.

Objective

We compared Foley catheter alone to different misoprostol dosages and administration routes, and the combination of Foley catheter with misoprostol.

Evidence acquisition

We reviewed the literature on the best induction method regarding their safety and effectiveness, using the outcome measures hyperstimulation, fetal distress, neonatal morbidity and mortality as well as cesarean delivery, vaginal instrumental delivery, and maternal morbidity. We searched Pubmed, Cochrane, and Web of Science from January 1, 1980 to February 12, 2016. Twenty-two randomized controlled trials (RCTs) were included, comparing Foley catheter with or without misoprostol to misoprostol alone (both vaginal and oral) for induction of labor (5,015 women).

Results

Most included studies were underpowered to detect differences in safety outcomes, as the majority are powered for time to delivery or cesarean delivery. Meta-analysis of these studies does not allow assessment of the safety profile of Foley catheter compared to misoprostol (any dose, any administration route) with sufficient power. For the safety outcomes of the total group of Foley catheter versus misoprostol (any dose, any administration route) (17 studies, 4,234 women) we found that Foley catheter results in less hyperstimulation compared to misoprostol (2% versus 4%; risk ratio [RR], 0.54; 95% confidence interval [CI], 0.37-0.79) and fewer cesarean deliveries for nonreassuring fetal heart rate, 5% vs 7%; RR, 0.72; 95% CI, 0.55-0.95; while there were no statistically significant differences in neonatal outcomes. The total number of cesarean deliveries was 26% versus 22% (RR, 1.16; 95% CI, 1.00-1.34). There were fewer vaginal instrumental deliveries with a Foley catheter compared to misoprostol (10% vs 14%; RR, 0.74; 95% CI, 0.60-0.91). Foley catheter with misoprostol compared to misoprostol alone (any dose, any administration route) (7 studies, 1,073 women) resulted in less hyperstimulation than misoprostol alone (17% vs 23%; RR, 0.71; 95% CI, 0.52-0.97). Cesarean deliveries for nonreassuring fetal heart rate were comparable (7% vs 9%; RR, 0.79; 95% CI, 0.51-1.22). Neonatal outcomes were infrequently reported. The total number of cesarean deliveries was 34% versus 34% (RR, 1.01; 95% CI, 0.86-1.19).

Conclusion

In women with an unripe cervix at term, Foley catheter seems to have a better safety profile than misoprostol (any dose, any administration route) for induction of labor. Larger studies are needed to investigate the safety profile of a Foley catheter compared to separate dosing and administration regimens of misoprostol.

Mechanical and Pharmacologic Methods of Labor Induction: A Randomized Controlled Trial

OBJECTIVE

To evaluate the effectiveness of four commonly used induction methods.

METHODS

This randomized trial compared four induction methods: misoprostol alone, Foley alone, misoprostol-cervical Foley concurrently, and Foley-oxytocin concurrently. Women undergoing labor induction with full-term (37 weeks of gestation or greater), singleton, vertex-presenting gestations, with no contraindication to vaginal delivery, intact membranes, Bishop score 6 or less, and cervical dilation 2 cm or less were included. Women were enrolled only once during the study period. Our primary outcome was time to delivery. Neither patients nor health care providers were blinded to assigned treatment group because examinations are required for placement of all methods; however, research personnel were blinded during data abstraction. A sample size of 123 per group (n=492) was planned to compare the four groups pairwise (P≤.008) with a 4-hour reduction in delivery time considered clinically meaningful.

RESULTS

From May 2013 through June 2015, 997 women were screened and 491 were randomized and analyzed. Demographic and clinical characteristics were similar among the four treatment groups. When comparing all induction method groups, combination methods achieved a faster median time to delivery than single-agent methods (misoprostol-Foley: 13.1 hours, Foley-oxytocin: 14.5 hours, misoprostol: 17.6 hours, Foley: 17.7 hours, P<.001). When censored for cesarean delivery and adjusting for parity, women who received misoprostol-Foley were almost twice as likely to deliver before women who received misoprostol alone (hazard ratio 1.92, 95% confidence interval [CI] 1.42-2.59) or Foley alone (hazard ratio 1.87, 95% CI 1.87 1.39-2.52), whereas Foley-oxytocin was not statistically different from single-agent methods.

CONCLUSION

After censoring for cesarean delivery and adjusting for parity, misoprostol-cervical Foley resulted in twice the chance of delivering before either single-agent method.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT01916681.

A comparison of inpatient with outpatient balloon catheter cervical ripening: a pilot randomized controlled trial

Background

One in four Australian births are induced. If cervical ripening using a prostaglandin is required, a pre-labour overnight hospitalisation and separation from family and support companions is necessary. Recent evidence shows that balloon catheter cervical ripening is just as effective as prostaglandins, but does not cause uterine stimulation. For women with low risk pregnancies, this offers the possibility of undergoing the overnight ripening process in their own home. We conducted a pilot randomised trial to assess the outcomes, clinical pathways and acceptability to both women and clinicians of outpatient balloon catheter ripening compared with usual inpatient care.

Methods

Forty-eight women with low risk term pregnancies were randomised (2:1) to either outpatient (n = 33) or inpatient double-balloon catheter (n = 15) cervical ripening. Although not powered for statistically significant differences, the study explored potential direction of effect for key clinical outcomes such as oxytocin use, caesarean section and morbidities. Feedback on acceptability was sought from women at catheter insertion and 4 weeks after the birth, and from midwives and doctors, at the end of the study.

Results

Clinical and perinatal outcomes were similar. Most women required oxytocin (77 %). The outpatient group were 24 % less likely to require oxytocin (risk difference −23.6 %, 95 % CI −43.8 to −3.5). There were no failed inductions, infections or uterine hyperstimulation attributable to the catheter in either group. Most women in both groups reported discomfort with insertion and wearing the catheter, but were equally satisfied with their care and felt the baby was safe (91 % both groups). Outpatient women reported feeling less isolated or emotionally alone. Most midwives and doctors (n = 90) agreed that they are more comfortable in sending home a woman with a catheter than prostaglandins and 90 % supported offering outpatient ripening to eligible women.

Conclusions

Outpatient balloon catheter ripening should be further investigated as an option for women in an adequately powered randomised trial.

Trial registration

Prospectively registered, Australian New Zealand Clinical Trials Registry ACTRN12612001184864.

[Double-balloon device and intravaginal dinoprostone for cervical ripening in women with unfavourable cervix]

OBJECTIVES

To compare the efficiency of a double cervical ripening (mechanical agent and dinoprostone) to a dinoprostone-only ripening in women with an unfavourable cervix.

METHODS

In a retrospective study from January 2008 to October 2013, 96 patients were included with the following criteria: pregnancies over 37 weeks, singleton, vertex presentation, medical indication for induction of labor, no premature rupture of membranes and very unfavourable cervix (Bishop score ≤ 3). Patients were classified into 2 groups: intravaginal dinoprostone for 24h (prostaglandin group, n=38) and double-balloon device for 12h followed by intravaginal dinoprostone for 24h (balloon+prostaglandin group, n=58).

RESULTS

There was no difference in vaginal delivery rates between the 2 groups (balloon+prostaglandin group 51.7%, prostaglandin group 50%, P=0.87). The Bishop score after cervical ripening was significantly higher in the balloon+prostaglandin group (4.4 versus 2.4, P<0.0001), but the interval between the induction and the delivery was longer (33.6h versus 24.9h, P=0.0044). There was no significant difference for maternal and neonatal complications.

CONCLUSION

A double cervical ripening (with mechanical agent and dinoprostone) allows the Bishop score to be improved without increasing the rate of vaginal delivery, for patients with a Bishop score ≤ 3.

Meta-analysis of Foley catheter plus misoprostol versus misoprostol alone for cervical ripening

BACKGROUND

The effectiveness of Foley catheter plus misoprostol for cervical ripening has not been convincingly shown in trials.

OBJECTIVES

To summarize the evidence comparing Foley catheter plus misoprostol versus misoprostol alone for cervical ripening.

SEARCH STRATEGY

Embase, Medline, and Cochrane Collaboration databases were searched with the terms "Foley catheter," "misoprostol," "cervical ripening," and "labor induction."

SELECTION CRITERIA

Randomized controlled trials comparing the methods of cervical ripening for delivery of a viable fetus were included.

DATA COLLECTION AND ANALYSIS

Study characteristics, quality, and outcomes were recorded. Random-effects models were used to combine data.

MAIN RESULTS

Eight trials were included, with 1153 patients overall. In a pooled analysis of seven high-quality studies, the combination group had a decreased time to delivery (mean difference -2.36 hours, 95% confidence interval [CI] -4.07 to -0.66; P=0.007). Risk of chorioamnionitis was significantly increased in the combination group (risk ratio [RR] 2.07, 95% CI 1.04-4.13; P=0.04), and that of tachysystole with fetal heart rate changes was decreased (RR 0.58, 95% CI 0.38-0.91; P=0.02). Frequency of cesarean did not differ (P=0.77).

CONCLUSIONS

The combined use of Foley catheter and misoprostol results in a reduced time to delivery, a reduced frequency tachysystole with fetal heart rate changes, and an increased incidence of chorioamnionitis.

Women's experiences of outpatient induction of labour with remote continuous monitoring

OBJECTIVE

to gain insight into women's experiences and preferences for induction in the home as part of a trial investigating the feasibility and acceptability of outpatient induction of labour with remote monitoring.

DESIGN

a qualitative study using semi-structured individual interviews. Interview transcripts were subjected to thematic analysis to identify the dominant themes regarding women's experiences of outpatient induction.

SETTING

a large maternity hospital in the North West of England.

PARTICIPANTS

fifteen women who participated in the main trial of outpatient induction of labour with remote continuous monitoring.

FINDINGS

three main themes were identified; the need for women to 'labour within their comfort zone'; their desire to achieve 'the next best thing to a normal labour' and the importance of a 'virtual presence' to offer remote reassurance.

CONCLUSIONS

women's preference for the outpatient setting of induction of labour is dominated by their need to labour within their comfort zone. Outpatient induction offered women the familiarity and freedom of the home environment, and the resulting physical and emotional comforts helped women cope better with their labour and improved their birth experiences. While remote monitoring offered some reassurance, women still depended on effective communication from hospital staff to provide the virtual presence of a health professional in the home.

IMPLICATIONS

the combination of slow-release prostaglandin and a remote monitoring device may provide low risk women with an improved induction and labour experience. While ongoing studies continue to explore further the safety of interventions at home, this study has importantly considered women's views and confirmed that induction at home is not only acceptable to women but also that the outpatient experience is preferable to long inpatient inductions.

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.

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.

The impact of duration of labor induction on cesarean rate

OBJECTIVE

We sought to determine maternal factors that influence success of labor induction and whether the probability of cesarean delivery changed with time during induction.

STUDY DESIGN

We performed a retrospective cohort study of 1650 singleton pregnancies induced at a gestation of 37 weeks or longer, with birthweights of 2500 g or greater, and without congenital anomalies. We used multivariate logistic regression to calculate odds ratios for cesarean.

RESULTS

Nulliparity (odds ratio [OR] 7.8, 95% confidence interval [CI] 5.7 to 11), hypertension (OR 1.4, 95% CI 1.1 to 1.8), diabetes (OR 2.2, 95% CI 1.6 to 3.1), maternal age 28.8 years old or older (OR 1.3, 95% CI 1.2 to 1.4), and birthweight of 3441 g or greater (OR 1.6, 95% CI 1.2 to 2.0) were significantly associated with cesarean. Cesarean risk increased linearly with time by an average of 3.8% per 6 hours.

CONCLUSION

Risk of cesarean increases over the duration of induction but does not reach clinical certainty. Cesarean probability is greater with nulliparity, hypertension, diabetes, older maternal age, or higher birthweight. Inductions without stated indications may not carry an increased risk of cesarean.

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.

Comparison of Labor Progression Between Induced and Noninduced Multiparous Women

OBJECTIVE

The incidence of labor induction is rising rapidly in the United States. Among multiparas, labor is often followed with traditional labor curves derived from noninduced pregnancies. We sought to determine how labor progression of multiparous women who presented in spontaneous labor differed from those who were electively induced with and from those induced without preinduction cervical ripening.

METHODS

We analyzed data on all low-risk multiparous women with an elective induction or spontaneous onset of labor between 37(+0) and 40(+6) weeks of gestation from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilatation and the risk of cesarean delivery were computed for 61 women with preinduction cervical ripening and oxytocin induction, 735 women with oxytocin induction, and 1,885 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix.

RESULTS

Those women who experienced electively induced labor without cervical ripening had a shorter active phase of labor than did those admitted in spontaneous labor (99 minutes in induced labor versus 161 minutes in spontaneous labor, P < .001). However, the cesarean delivery rate was elevated in the induction group (3.9% versus 2.3%, P < .05). Women who underwent preinduction cervical ripening also had a shorter active phase than those admitted in spontaneous labor (109 minutes versus 161 minutes, P = .01).

CONCLUSION

The pattern of labor progression differs for women with an electively induced labor without cervical ripening compared with those who present with spontaneous onset of labor.

Induction of labor using a foley balloon, with and without extra-amniotic saline infusion

OBJECTIVE

To compare transcervical Foley bulb with and without extra-amniotic saline infusion for induction of labor in patients with an unfavorable cervix.

METHODS

Women who presented for induction of labor with Bishop score less than 5 were randomly assigned to receive Foley alone or Foley with extra-amniotic saline infusion for induction of labor. Primary outcome was time from start of induction to vaginal delivery. Secondary outcomes were cesarean delivery rates, incidence of chorioamnionitis, Apgar scores at 1 and 5 minutes, and adverse events.

RESULTS

One hundred forty women completed the study. Time from induction to vaginal delivery was 16.58 (+/- 7.55) hours in the extra-amniotic saline infusion group compared with 21.47 (+/- 9.95) hours in the Foley group (P < .01). Chorioamnionitis occurred in 4 of 66 (6.1%) women in the extra-amniotic saline infusion group compared with 12 of 74 (16.2%) women in the Foley group (P = .067). Cesarean delivery rate was 21.2% versus 20.1% in the extra-amniotic saline infusion and Foley groups, respectively (P = 1.0). Median 1-minute and 5-minute Apgar scores were 9 in both groups. Adverse events were rare and unrelated to method of induction.

CONCLUSION

Induction of labor by using Foley with extra-amniotic saline infusion results in shorter induction-to-vaginal-delivery time than Foley alone, without affecting cesarean delivery rates.

LEVEL OF EVIDENCE

II-I

Labor Progression and Risk of Cesarean Delivery in Electively Induced Nulliparas

OBJECTIVE

To describe the pattern of labor progression and risk of cesarean delivery in women whose labor was electively induced.

METHODS

We analyzed data on all low-risk, nulliparous women with an elective induction or spontaneous onset of labor between 37 + 0 and 40 + 6 weeks from January 2002 to March 2004 at a single institution. The median duration of labor by each centimeter of cervical dilation and the risk of cesarean delivery were computed for 143 women with preinduction cervical ripening and oxytocin induction, 286 women with oxytocin induction, and 1,771 women with a spontaneous onset of labor. An intracervical Foley catheter was used to ripen the cervix.

RESULTS

Electively induced labor with cervical ripening had substantially slower latent and early active phases. After controlling for potential confounders, women who had an elective induction with cervical ripening had 3.5 times the risk of cesarean delivery during the first stage of labor (95% confidence interval 2.7-4.5), compared with those admitted in spontaneous labor. Elective induction without cervical ripening, on the other hand, was associated with a faster labor progression from 4 to 10 cm (266 compared with 358 minutes, P < .01) and did not increase the risk of cesarean delivery, compared with those in spontaneous labor.

CONCLUSION

The pattern of labor progression differs substantially for women with an electively induced labor compared with those with spontaneous onset of labor. Furthermore, elective induction in nulliparous women with an unfavorable cervix has a high rate of labor arrest and a substantially increased risk of cesarean delivery.

LEVEL OF EVIDENCE

II-2.

Oral misoprostol versus intracervical dinoprostone for induction of labor

OBJECTIVES

To compare oral misoprostol with dinoprostone for induction of labor and their effects on the fetal heart rate patterns.

METHODS

In a randomized controlled trial, 200 patients received either misoprostol 50 mug orally for every 4 h, or dinoprostone 0.5 mg intracervically for every 6 h. Cardiotocographic recordings, in 10-min windows 30, 60, and 80 min after prostaglandin administration during induction and continuously during labor, were compared between the two groups. Primary outcome for effectiveness and safety was assessed in terms of the number of vaginal deliveries within 24 h and fetal heart rate abnormalities during induction and labor respectively.

RESULTS

Data from 96 patients in the misoprostol group and 95 in the dinoprostone group were analyzed. There were no significant differences in respect of the number of vaginal deliveries within 24 h (RR 1.12; 95% CI 0.88-1.42). The frequency of suspicious and pathological fetal heart rate patterns did not differ significantly but significantly more cardiotocographs in the dinoprostone group had non-reassuring baseline variability 60 min after dose administration (RR 0.33; 95% CI 0.14-0.77). Maternal and neonatal outcomes did not differ significantly.

CONCLUSION

Oral misoprostol is as effective as intracervical dinoprostone for induction of labor with no difference in the frequency of fetal heart rate abnormalities.

Unsucessful labour induction in women with unfavourable cervical scores: predictors and management

BACKGROUND

Misoprostol fails to induce labour in 5-20% of women at term.

AIM

To analyse possible predictors of unsuccessful induction with 50 microg vaginal misoprostol and effectiveness and the safety of intracervical Foley catheter application in induction failures.

METHODS

An observational study was conducted on 1030 women with singleton, live fetuses, vertex presentation, > 34 weeks of gestation and Bishop score < 5. Induction of labour with 50 microg vaginal misoprostol repeated every 6 h was attempted. Women without regular uterine contractions and cervical changes at the end of 24 h were considered to be unsuccessful, and a transcervical Foley balloon catheter was placed and inflated with 50 mL saline. Possible predictors of induction failures were analysed via logistic regression analysis. Neonatal outcomes and vaginal delivery achieved after Foley catheter were also determined.

RESULTS

Induction was successful in 918 cases (89.1%) and Foley catheter was placed in 112 (10.8%) women. Increasing gestational age in weeks (odds ratio [OR] 0.77, 95% confidence interval [CI] 0.68-0.88) and increasing Bishop score (OR 0.73, 95% CI 0.60-0.90) decreased the risk of failed induction. Failure rates were 16% (27/169) in post-term nulliparous women with Bishop score </= 1 and 40% (4/10) in preterm women with Bishop score </= 1. Foley catheter achieved vaginal delivery in 83% of these women without causing an increase in the adverse neonatal outcomes.

CONCLUSION

When misoprostol induction fails, Foley catheter is a safe and effective method for cervical ripening. Foley catheter can be the first treatment of choice in post-term nulliparous women or preterm women with Bishop score </= 1.

A randomized trial comparing a 30-mL and an 80-mL Foley catheter balloon for preinduction cervical ripening

OBJECTIVES

The purpose of this study was to compare the efficacy of cervical ripening with 2 Foley catheter balloon volumes.

STUDY DESIGN

Pregnant women admitted for induction of labor with a term singleton gestation were randomly assigned for cervical ripening by a balloon inflated with 30 mL or 80 mL of sterile saline.

RESULTS

Two hundred and three women were included in the analysis. Ripening of the cervix with the larger balloon volume was associated with a significantly higher rate of post-ripening dilatation of 3 cm or more (76.0% vs 52.4%, P < .001). In primiparous women, the larger balloon volume resulted in a significantly higher rate of deliveries by 24 hours (71.4% vs 49%, P < .05), and a significantly less requirement of augmentation with oxytocin (69.3% vs 90.4%, P < .05).

CONCLUSION

Ripening of the unfavorable cervix in primiparous women with a Foley catheter balloon inflated with 80 mL provided effective more dilatation, faster labor, and decreased need for oxytocin than with a balloon inflated with 30 mL of sterile saline.

Misoprostol and pregnancy: ever-increasing indications of effective usage

PURPOSE OF REVIEW

The subject of misoprostol in the field of reproductive health care has courted much controversy. The aim of this review is to survey the literature published in this field over the past year, and to evaluate developments in this area. This article will cover termination of pregnancy, induction of labor and the issue of postpartum hemorrhage.

RECENT FINDINGS

The use of misoprostol as a single agent remains of clinical value when mifepristone is unavailable. The sublingual and rectal routes are alternative modes of administration. For induction of labor, the optimum dose and route of misoprostol is still undetermined. Lower doses of between 20 microg to 40 microg may increase the safety profile for labor induction. Misoprostol may be a useful adjunct to the therapeutic options available for the prevention and treatment of postpartum hemorrhage.

SUMMARY

There are many potential uses for misoprostol in pregnancy. However clinicians must judge the evidence and the emotive debate surrounding this field and decide how it will influence their clinical practice depending on the priorities of their own clinical circumstances.

A randomised comparison of oral misoprostol and vaginal prostaglandin E2 tablets in labour induction at term

OBJECTIVE

To compare the efficacy of 100 microg of oral misoprostol with 3 mg prostaglandin E2 vaginal tablets in term labour induction.

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level, teaching Scottish Hospital.

POPULATION

Two hundred women at term with indications for labour induction and modified Bishop's cervical score of less than 8.

METHODS

The women were randomly allocated to receive either 100 microg of misoprostol orally (which could be repeated 4 hourly to a maximum of five doses if indicated), or a 3 mg tablet of prostaglandin E2 vaginally (which could be repeated in 6 hours, according to routine departmental protocol).

MAIN OUTCOME MEASURE

The number delivering vaginally within 24 hours of the induction.

RESULTS

Seventy-five women delivered vaginally in the misoprostol group and 73 in the PGE2 group. Of these, 50.7% in the misoprostol group and 54.8% in the PGE2 group delivered within 24 hours of the induction (RR 0.92, 95% CI 0.7 to 1.3). More women in the misoprostol group were given oxytocin, but this was not statistically significant (60%vs 47%, RR 1.3, 95% CI 0.98 to 1.7). Two women in the misoprostol group had uterine hyperstimulation. The neonatal outcomes were not significantly different in the two groups. There was a pound 1100 saving on direct drug costs in the misoprostol group.

CONCLUSIONS

Oral misoprostol (100 microg) has similar efficacy to vaginal PGE2 tablets, and may be an option to consider for term labour induction.