A randomized comparison of transcervical Foley catheter to intravaginal misoprostol for preinduction cervical ripening

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Inpatient versus outpatient induction of labour: a systematic review and meta-analysis

Background

As the number of indications for labour induction continue to increase, the focus has shifted to performing these procedures in an outpatient setting. This study aims to systematically review published data from randomized controlled trials that compare outpatient with inpatient labour induction, to ascertain the role of outpatient labour induction for low-risk pregnancies.

Methods

We conducted a systematic review wherein we searched MEDLINE, EMBASE, Biosis Previews®, and International Pharmaceutical Abstracts from inception to January 2020 to identify randomized controlled trials that reported on maternal, fetal and resource-related outcomes following outpatient versus inpatient labour induction. Pooled incidences and mean differences were calculated using random-effects meta-analysis. Risk-of-bias was assessed using the Cochrane Risk of Bias tool. Subgroup analysis was conducted based on the method of induction.

Results

Of the 588 records identified, 12 publications, representing nine independent randomized controlled trials conducted in Australia, Europe and North America, were included. These reported on 2615 cases of labour induction (1320 outpatients versus 1295 inpatients). Overall, apart from a higher number of suspicious fetal heart rate tracings [RR = 1.43 (1.10, 1.86)] and a shorter mean length of hospital stay [MD = 282.48 min (160.23, 404.73) shorter] in the outpatient group, there were no differences in delivery method, adverse outcomes or resource-use between the two arms. On subgroup analysis, when comparing the use of balloon catheters in both arms, those induced as outpatients had fewer caesarean deliveries [RR = 0.52 (0.30, 0.90)], a shorter admission-to-delivery interval [MD = 370.86 min (19.19, 722.54) shorter], and a shorter induction to delivery interval [MD = 330.42 min (120.13, 540.71) shorter].

Conclusion

Outpatient labour induction in resource-rich settings is at least as effective and safe, in carefully selected patient populations, when compared with inpatient labour induction. Whether outpatient labour induction results in lower rates of caesarean deliveries needs to be explored further.

Trial registration

This systematic review was prospectively registered in Prospero (CRD42019118049).

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.

Methods of term labour induction for women with a previous caesarean section

BACKGROUND

Women with a prior caesarean delivery have an increased risk of uterine rupture and for women subsequently requiring induction of labour it is unclear which method is preferable to avoid adverse outcomes. This is an update of a review that was published in 2013.

OBJECTIVES

To assess the benefits and harms associated with different methods used to induce labour in women who have had a previous caesarean birth.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (31 August 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any method of third trimester cervical ripening or labour induction, with placebo/no treatment or other methods in women with prior caesarean section requiring labour induction in a subsequent pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and trial quality, extracted data, and checked them for accuracy.

MAIN RESULTS

Eight studies (data from 707 women and babies) are included in this updated review. Meta-analysis was not possible because studies compared different methods of labour induction. All included studies had at least one design limitation (i.e. lack of blinding, sample attrition, other bias, or reporting bias). One study stopped prematurely due to safety concerns. Vaginal PGE2 versus intravenous oxytocin (one trial, 42 women): no clear differences for caesarean section (risk ratio (RR) 0.67, 95% confidence interval (CI) 0.22 to 2.03, evidence graded low), serious neonatal morbidity or perinatal death (RR 3.00, 95% CI 0.13 to 69.70, evidence graded low), serious maternal morbidity or death (RR 3.00, 95% CI 0.13 to 69.70, evidence graded low). Also no clear differences between groups for the reported secondary outcomes. The GRADE outcomes vaginal delivery not achieved within 24 hours, and uterine hyperstimulation with fetal heart rate changes were not reported. Vaginal misoprostol versus intravenous oxytocin (one trial, 38 women): this trial stopped early because one woman who received misoprostol had a uterine rupture (RR 3.67, 95% CI 0.16 to 84.66) and one had uterine dehiscence. No other outcomes (including GRADE outcomes) were reported. Foley catheter versus intravenous oxytocin (one trial, subgroup of 53 women): no clear difference between groups for vaginal delivery not achieved within 24 hours (RR 1.47, 95% CI 0.89 to 2.44, evidence graded low), uterine hyperstimulation with fetal heart rate changes (RR 3.11, 95% CI 0.13 to 73.09, evidence graded low), and caesarean section (RR 0.93, 95% CI 0.45 to 1.92, evidence graded low). There were also no clear differences between groups for the reported secondary outcomes. The following GRADE outcomes were not reported: serious neonatal morbidity or perinatal death, and serious maternal morbidity or death. Double-balloon catheter versus vaginal PGE2 (one trial, subgroup of 26 women): no clear difference in caesarean section (RR 0.97, 95% CI 0.41 to 2.32, evidence graded very low). Vaginal delivery not achieved within 24 hours, uterine hyperstimulation with fetal heart rate changes, serious neonatal morbidity or perinatal death, and serious maternal morbidity or death were not reported. Oral mifepristone versus Foley catheter (one trial, 107 women): no primary/GRADE outcomes were reported. Fewer women induced with mifepristone required oxytocin augmentation (RR 0.54, 95% CI 0.38 to 0.76). There were slightly fewer cases of uterine rupture among women who received mifepristone, however this was not a clear difference between groups (RR 0.29, 95% CI 0.08 to 1.02). No other secondary outcomes were reported. Vaginal isosorbide mononitrate (IMN) versus Foley catheter (one trial, 80 women): fewer women induced with IMN achieved a vaginal delivery within 24 hours (RR 2.62, 95% CI 1.32 to 5.21, evidence graded low). There was no difference between groups in the number of women who had a caesarean section (RR 1.00, 95% CI 0.39 to 2.59, evidence graded very low). More women induced with IMN required oxytocin augmentation (RR 1.65, 95% CI 1.17 to 2.32). There were no clear differences in the other reported secondary outcomes. The following GRADE outcomes were not reported: uterine hyperstimulation with fetal heart rate changes, serious neonatal morbidity or perinatal death, and serious maternal morbidity or death. 80 mL versus 30 mL Foley catheter (one trial, 154 women): no clear difference between groups for the primary outcomes: vaginal delivery not achieved within 24 hours (RR 1.05, 95% CI 0.91 to 1.20, evidence graded moderate) and caesarean section (RR 1.05, 95% CI 0.89 to 1.24, evidence graded moderate). However, more women induced using a 30 mL Foley catheter required oxytocin augmentation (RR 0.81, 95% CI 0.66 to 0.98). There were no clear differences between groups for other secondary outcomes reported. Several GRADE outcomes were not reported: uterine hyperstimulation with fetal heart rate changes, serious neonatal morbidity or perinatal death, and serious maternal morbidity or death. Vaginal PGE2 pessary versus vaginal PGE2 tablet (one trial, 200 women): no difference between groups for caesarean section (RR 1.09, 95% CI 0.74 to 1.60, evidence graded very low), or any of the reported secondary outcomes. Several GRADE outcomes were not reported: vaginal delivery not achieved within 24 hours, uterine hyperstimulation with fetal heart rate changes, serious neonatal morbidity or perinatal death, and serious maternal morbidity or death.

AUTHORS' CONCLUSIONS

RCT evidence on methods of induction of labour for women with a prior caesarean section is inadequate, and studies are underpowered to detect clinically relevant differences for many outcomes. Several studies reported few of our prespecified outcomes and reporting of infant outcomes was especially scarce. The GRADE level for quality of evidence was moderate to very low, due to imprecision and study design limitations.High-quality, adequately-powered RCTs would be the best approach to determine the optimal method for induction of labour in women with a prior caesarean birth. However, such trials are unlikely to be undertaken due to the very large numbers needed to investigate the risk of infrequent but serious adverse outcomes (e.g. uterine rupture). Observational studies (cohort studies), including different methods of cervical ripening, may be the best alternative. Studies could compare methods believed to provide effective induction of labour with low risk of serious harm, and report the outcomes listed in this review.

Foley catheter for induction of labor: potential barriers to adopting the technique

OBJECTIVE

To evaluate if a learning curve exists for cervical Foley placement for labor induction in women with unfavorable cervices and whether labor curves differ compared with the dinoprostone insert (PGE2).

STUDY DESIGN

We conducted a secondary analysis of a multicenter randomized controlled trial.

RESULT

For Foley and PGE2, successful placement occurred in 157/185 (85%) and 188/191 (98%) women (P<0.001). Unsuccessful Foley placements decreased over time (P=0.005); all occurred at the site previously using PGE2 preferentially. In women with allocated agent placed successfully who achieved complete cervical dilation, median progress with Foley (n=112), compared with PGE2 (n=123), was: 1-3 cm (6.2 vs 14.1 h; P<0.001), 3-6 cm (11.1 vs 6.7 h; P<0.001) and 6-10 cm (1.9 vs 1.5 h; P=0.14).

CONCLUSION

There is a learning curve for placing cervical Foley catheters. Despite faster times to delivery, Foley is associated with slower dilation from 3 to 6 cm compared with PGE2.

Labor induction utilizing the Foley balloon: a randomized trial comparing standard placement versus immediate removal

OBJECTIVE

To compare time to delivery between two induction procedures. The Foley balloon is a mechanical method for cervical ripening. However, the device may also result in endogenous prostaglandin release following separation of the chorionic membrane and decidua. Prolonged Foley placement may therefore be unnecessary for successful labor induction.

METHOD

Randomized controlled trial of labor induction at LAC+USC Medical Center between 2010 and 2013. Subjects were assigned to either (a) standard placement of the Foley balloon or (b) Foley balloon insufflation and immediate removal. Oxytocin was administered to all subjects not in active labor after 12 h. Delivery information and neonatal outcomes were documented and all patients were followed for 6 weeks for adverse events.

RESULT

A total of 79 women were included in the analysis (37 standard and 42 immediate). Induction time was 8.6 h longer in the immediate removal group (23.5 vs 32.1, P=0.002), but the difference in delivery within 24 h did not meet the statistical significance (46.0 vs 28.6%, P=0.11). Similar rates of cesarean delivery, epidural use and abnormal APGAR scores were observed. After controlling for number of vaginal exams and duration of rupture, a decreased risk of infection was observed in the immediate removal group (odds ratio=0.08, 95% confidence interval=0.007 to 0.93, P=0.04). Further, when the analysis was stratified by parity, differences in induction time only persisted in nulliparous women.

CONCLUSION

Immediate removal of the Foley balloon may lead to longer overall induction time, but a lower risk of infection. Parous women may be particularly good candidates for this type of induction.

Progress of labor in women induced with misoprostol versus the Foley catheter

OBJECTIVE

To estimate and compare the duration and progress of labor in women induced with misoprostol vs Foley catheter plus oxytocin.

STUDY DESIGN

We performed a retrospective cohort study of labor progress among 617 consecutive term pregnancies induced with misoprostol (n = 503) or Foley catheter plus oxytocin (n = 114) who completed the first stage of labor. Labor duration and progress in the entire cohort, and stratified by parity, were compared in multivariable interval-censored regression models adjusting for maternal obesity and birthweight. Repeated-measures analysis with 9th degree polynomial modeling was used to construct average labor curves.

RESULTS

Total duration of labor was not significantly different in women induced with misoprostol compared with the Foley catheter (median duration from 1 to 10 cm: 12 vs 14.2 hours, P = .19). Progress from 1 to 4 cm was more rapid with the Foley catheter (median: 3.4 vs 5.6 hours, P < .01), although progress from 4 to 10 cm was slower (median: 6.3 vs 3.6 hours, P < .01). Labor curves demonstrated transition from latent to active labor at about 4 cm cervical dilatation with misoprostol and at 6 cm for the Foley catheter. Similar general patterns were noted for nulliparous and multiparous women, except for a shorter duration of labor with the Foley catheter among multiparous women.

CONCLUSION

Induction of labor with the Foley catheter is associated with more rapid initial cervical dilation, but transition to active labor occurs later compared with misoprostol. These differences should be considered in the management of induced labor.

Inner thigh taping vs traction for cervical ripening with a Foley catheter: a randomized controlled trial

OBJECTIVE

To assess the effectiveness of inner thigh "Taping" compared with "Traction" using a weighted bag when an intracervical Foley catheter is used for cervical ripening.

STUDY DESIGN

We performed a randomized controlled trial at a tertiary hospital on women with a singleton pregnancy in cephalic presentation admitted for labor induction with a Bishop score ≤6. A 30 mL intracervical Foley catheter was placed for ripening. Women were randomly allocated to inner thigh Taping or to Traction with a 500 mL weighted bag of fluid. The primary outcome was time to delivery. Secondary outcomes were time to expulsion of the catheter, maternal discomfort (visual analog scale), mode of delivery, and maternal morbidities.

RESULTS

We randomized 197 women. After exclusions (4 ineligible, 2 withdrawn by provider), we analyzed 191 (96 Taping, 95 Traction) women in their assigned groups. Groups were similar regarding maternal race, age, parity, gestational age, and induction indication. Time to delivery was not significantly different (mean ± standard deviation: 19.8 ± 8.5 vs 18.8 ± 8.0 hours; P = .39). Time to catheter expulsion was shorter in the Traction Group (median, 2.6; range, 0.2-10.8 vs median, 1.5; range, 0.1-6.3 hours; P < .001). Change in Bishop and pain scores, cesarean delivery rates, clinical amnionitis, and other maternal morbidities were similar between groups. Subset analyses of those with vaginal delivery and among nulliparas, and multiparas revealed similar results.

CONCLUSION

Traction on the intracervical Foley catheter during cervical ripening shortens the time to spontaneous catheter expulsion without affecting the time to delivery.

Foley catheter versus intra-vaginal misoprostol for induction of labor in post-term gestations

OBJECTIVE

To investigate whether a fluid filled intra-uterine extra-amniotic Foley catheter is an effective alternative to vaginal misoprostol in inducing labor in primigravid women with post-term gestations.

PATIENTS AND METHODS

A prospective quasi-randomized controlled trial was designed and 100 primigravid women with post-term gestations were enrolled and equally allocated into two groups. A fluid filled intra-uterine extra-amniotic Foley catheter was inserted in women of group I. Women in group II received 25 microgram misoprostol vaginally every 4 h. Artificial rupture of membranes was performed for all women when their cervices reached 3-4 cm dilatation followed by oxytocin infusion if needed. The main primary outcome parameter was the induction to delivery interval. Results were tabulated and statistically analyzed.

RESULTS

No significant difference was noted in any of the demographic data between both groups. The induction to delivery interval was shorter in the Foley group (897.36 ± 116.0 vs. 960.98 ± 94.18 min; P = 0.003). There were 34 cases which needed oxytocin augmentation in group I compared to 11 cases in group II (P < 0.01). Abnormal uterine activity occurred in three cases in the misoprostol group, but none in the Foley group. Ominous fetal heart rate was noted in one case in group I but three in group II.

CONCLUSION

Fluid filled Foley catheter seems to be superior to 25 μg vaginal misoprostol regimen, when used to induce labor in primigravidae with post-term gestations with the advantage of having a shorter induction delivery interval, but more need for oxytocin augmentation.

Induction of labor in prolonged pregnancy with unfavorable cervix: comparison of sequential intracervical Foley catheter-intravaginal misoprostol and intravaginal misoprostol alone

PURPOSE

To compare the outcome of induced labor at term using sequential intracervical Foley catheter with intravaginal misoprostol versus intravaginal misoprostol alone.

METHODS

A prospective matched case control study among parturient with prolonged pregnancy and unfavorable cervix at a tertiary hospital in Nigeria.

RESULTS

The study population was 100 with a mean age of 29.46 ± 3.88 years. Parturient with prior cervical priming using intracervical Foley catheter had significantly lower oxytocin augmentation of uterine contractions in labor (44 vs. 64%, P = 0.045), shorter mean insertion to active phase labor duration (233 ± 98 vs. 354 ± 154 min, P = 0.0001), shorter insertion to delivery interval (514 ± 175 vs. 627 ± 268, P = 0.014), more vaginal delivery <12 h (92.5 vs. 60%, P = 0.001) and less delivery by caesarean section (20 vs. 40%, P = 0.029).

CONCLUSIONS

The sequential combination of intracervical Foley catheter and intravaginal misoprostol for cervical ripening and induction of labor appears to be a safe and more effective method compared to intravaginal misoprostol in parturient at term with unfavorable cervices.

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.

Intravaginal misoprostol versus Foley catheter for labour induction: a meta-analysis

BACKGROUND

There are a number of agents used for cervical ripening prior to the induction of labour. Two commonly used agents are intravaginal misoprostol and a transcervical Foley catheter.

OBJECTIVE

To review the evidence comparing misoprostol and transcervical Foley catheter placement for induction of labour, and perform a meta-analysis comparing these two induction agents.

SEARCH STRATEGY

We conducted database searches of PubMed, Embase, the Cochrane Library Database, and the ClinicalTrials.gov website. Bibliographies of all relevant articles were reviewed.

SELECTION CRITERIA

Prospective, randomised trials comparing the use of intravaginal misoprostol and transcervical Foley catheter for the purpose of cervical ripening and induction of labour were included. We excluded studies in which the patients in these two intervention groups also received other induction agents concurrently, such as oral misoprostol, oxytocin, or other prostaglandins.

DATA COLLECTION AND ANALYSIS

The primary outcomes selected were time to delivery, and the rates of caesarean section, uterine tachysystole, and chorioamnionitis. Random-effects generalised linear models with a poisson distribution and log link function were used to compare the two induction agents across the studies.

MAIN RESULTS

Nine studies (1603 patients) were identified as eligible to be included in this meta-analysis. There were no significant differences in the mean time to delivery (mean difference 1.08 ± 2.19 hours shorter for misoprostol, P = 0.2348), the rate of caesarean delivery (RR 0.991; 95% CI 0.768, 1.278), or in the rate of chorioamnionitis (RR 1.130; 95% CI 0.611, 2.089) between women who received misoprostol compared with transcervical Foley catheter. Patients who received misoprostol had significantly higher rates of tachysystole compared with women who received a transcervical Foley catheter (RR 2.844; 95% CI 1.392, 5.812).

CONCLUSIONS

Intravaginal misoprostol and transcervical Foley catheter have similar effectiveness as induction agents. Transcervical Foley catheter is associated with a lower incidence of tachysystole.

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.

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.

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

Induction of labor with three different techniques at 41 weeks of gestation or spontaneous follow-up until 42 weeks in women with definitely unfavorable cervical scores

OBJECTIVE

To compare the obstetric outcome of induction of labor at 41 weeks and of follow-up until 42 weeks and induction if the patient has still not given birth at 42 weeks.

STUDY DESIGN

Six hundred women at 287+/-1 days of gestation with definitely unfavorable cervical scores were randomized to labor induction (N=300) or spontaneous follow-up (N=300) with twice-weekly nonstress testing and amniotic fluid measurement and once-weekly biophysical scoring. The treatments used in the induction group were (1) vaginal administration of 50 microg misoprostol (n=100), (2) oxytocin induction (n=100), and (3) transcervical insertion of a Foley balloon (n=100). The primary outcome measures were the cesarean delivery rate, whether or not the normal hospital stay had to be extended, and the neonatal outcomes. Secondary outcome measure included number of emergency cesarean deliveries performed for abnormalities of the fetal heart rate (FHR).

RESULTS

The abdominal delivery rate was 19.3% in the induction group and 22% in the follow-up group (p=0.4). The mean length of hospital stay in the two main groups was 1.4+/-0.8 days and 1.3+/-1 days, respectively (p=0.1). Significantly higher rates of macrosomia and shoulder dystocia were seen in the follow-up group (24.6 and 2.3%) than in the induction group (7.6%, p<0.001; 0.3%, p=0.03). Meconium-stained amniotic fluid and meconium aspiration syndrome were observed significantly less frequently in the induction group (9.3 and 1.3%) than in the follow-up group (20.3%, p<0.001; 4%, p=0.03). Rates of emergency abdominal delivery in response to worrying FHR traces, neonatal intensive care unit admission, and low umblical artery pH were similar in the two groups. There was one intrauterine fetal death in the follow-up group.

CONCLUSION

Induction of labor at 41 weeks of gestation does not increase the cesarean delivery rate or cause a longer stay in hospital than follow-up until 42 weeks, and neonatal morbidity is also lower after induction.

Uterine Rupture during Second Trimester Abortion with Misoprostol

BACKGROUND

Data are limited regarding the use of misoprostol in the midtrimester, therefore few cases with uterine rupture during the second trimester with a previous uterine scar have been reported in the literature.

CASE REPORT

A 23-year-old woman with a prior low transverse cesarean section presented at 26 weeks' gestation for pregnancy termination for a fetal abnormality. She was given 200 microg misoprostol intravaginally every 3 h until regular contractions began. After the fourth dose, she had vaginal bleeding and severe contractions. She aborted completely 2 h later after the last dose. Uterine rupture was diagnosed at the previous cesarean section scar by manual vaginal examination. She underwent emergency laparotomy and the uterus was repaired.

CONCLUSION

Misoprostol use in the second trimester in a woman with a uterine scar can trigger severe contractions that can lead to uterine rupture.

Use of the Atad catheter for the induction of labour in women who have had a previous Caesarean section - a case series

Abstract The induction of labour of women with an unfavourable cervix who have had a previous Caesarean section, is challenging. Eight women who had a Caesarean section in a previous pregnancy had labour induced with an Atad catheter. Six out of eight women achieved labour, and two out of these six women had a vaginal delivery. An Atad catheter is an option for women needing induction of labour with an unfavourable cervix who have had a Caesarean section previously and are motivated to have a vaginal delivery.

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.

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.

Preinduction cervical ripening with the Foley catheter and the risk of subsequent preterm birth

OBJECTIVE

The Foley catheter is a safe and effective form of preinduction cervical ripening and is quickly growing in popularity. Its major effect appears to be through mechanical dilation, which has raised the concern that the use of the Foley catheter for cervical ripening may damage the cervix and result in a higher rate of subsequent preterm birth.

STUDY DESIGN

We conducted a review of all induction of labor at our institution from July 1998 to July 2001 that required preinduction cervical ripening and had a subsequent birth. The primary outcome variable was preterm birth at <35 weeks of gestation. Demographic and potential confounding variables were analyzed. A probability value of <.05 was considered significant.

RESULTS

The cases of 126 women (63 women in the Foley group and 63 women in the prostaglandin group) were studied. Women in the prostaglandin group had a prostaglandin agent used. There was no difference in maternal age, gravidity, parity, Bishop score, total time of induction, gestational age, oxytocin use, maximum oxytocin level, tobacco or drug use, or type of delivery in the index pregnancy between the groups. In the subsequent pregnancies, there were no differences in maternal age, gravidity, parity, spontaneous abortions, terminations, cone or Loop Electrosurgical Excision Procedure (LEEP) procedures, history of cervical manipulation, tobacco or drug use, stillbirth, need for induction, mode of delivery, episiotomy, gestational age at delivery, Apgar scores, labor duration, use of oxytocin, or birth weight. There were no differences in preterm birth at 37, 35, or 32 weeks of gestation between the groups.

CONCLUSION

The use of the Foley catheter for preinduction cervical ripening does not appear to increase the risk of preterm birth in a subsequent pregnancy.

Cervical Ripening With Transcervical Foley Catheter and the Risk of Uterine Rupture

OBJECTIVE

To estimate whether the rate of uterine rupture in patients with a previous cesarean delivery is related to labor induction and/or cervical ripening using transcervical Foley catheter.

METHODS

Charts of all patients who had a trial of labor after a previous cesarean delivery in our institution between 1988 and 2002 were reviewed. The rates of successful vaginal birth after cesarean delivery and uterine rupture in patients with spontaneous labor (control group) were compared with those of patients who underwent a labor induction by means of amniotomy with or without oxytocin and patients who underwent a labor induction/cervical ripening using a transcervical Foley catheter. Logistic regression analysis was performed to adjust for confounding variables.

RESULTS

Of 2479 patients, 1807 had a spontaneous labor, 417 had labor induced by amniotomy with or without oxytocin, and 255 had labor induced by using transcervical Foley catheter. The rate of successful vaginal birth after cesarean delivery was significantly different among the groups (78.0% versus 77.9% versus 55.7%, P <.001), but not the rate of uterine rupture (1.1% versus 1.2% versus 1.6%, P =.81). After adjusting for confounding variables, the odds ratio (OR) for successful vaginal birth after cesarean delivery was 0.68 (95% confidence interval [CI] 0.41, 1.15), and the OR for uterine rupture was 0.47 (95% CI 0.06, 3.59) in patients who underwent an induction of labor using a transcervical Foley catheter when compared with patients with spontaneous labor.

CONCLUSION

Labor induction using a transcervical Foley catheter was not associated with an increased risk of uterine rupture.

Induction of labour with an unfavourable cervix

Labour induction is undertaken when the advantages for the mother and/or the baby are considered to outweigh the disadvantages. When the uterine cervix is unfavourable, oxytocin, with or without amniotomy, is frequently ineffective. Vaginal prostaglandin E(2) is most commonly used if it is affordable. Evidence regarding many alternative methods is discussed in this chapter. Of particular interest are misoprostol and extra-amniotic saline infusion.Misoprostol, an orally active prostaglandin E(1) analogue, has been used widely by the vaginal and oral routes for labour induction at or near term. Several recent trials have confirmed that it is highly effective. Overall Caesarean section rates appear to be reduced, despite a relative increase in Caesarean sections for fetal heart rate abnormalities. Concern remains regarding increased rates of uterine hyperstimulation and meconium-stained amniotic fluid, although data on perinatal outcome have been reassuring. Postpartum haemorrhage may be increased following labour induction with misoprostol, and isolated reports of uterine rupture, with or without previous Caesarean section, have appeared. Using small dosages appears to reduce adverse outcomes. Very large trials are needed to evaluate rare adverse outcomes.Extra-amniotic saline infusion is an effective method which appears to reduce the risk of uterine hyperstimulation that occurs with the use of exogenous uterotonics.

A comparison of vaginally administered misoprostol with extra-amniotic saline solution infusion for cervical ripening and labor induction

OBJECTIVE

The purpose of this study was to compare intravaginal misoprostol with extra-amniotic saline solution infusion with concomitant oxytocin for cervical ripening and labor induction in viable pregnancies.

STUDY DESIGN

Two hundred women with indications for labor induction and unfavorable cervices were assigned randomly to vaginal misoprostol or extra-amniotic saline solution infusion. Twenty-five micrograms of misoprostol was administered every 4 hours up to six doses, followed by intravenous oxytocin administration. Patients who had received extra-amniotic saline solution infusion also received intravenous oxytocin along with a maximum 12-hour saline solution infusion through Foley catheters that were placed above the internal cervical os.

RESULTS

One hundred women were randomly assigned to misoprostol, and 100 women were assigned randomly to extra-amniotic saline solution infusion. The average interval from start of induction to vaginal delivery was longer in the misoprostol group (1323.3 +/- 700.3 minutes) than in the extra-amniotic saline solution infusion group (970.4 +/- 502.7 minutes; P =.006, log transformed data). Abnormal fetal heart rate tracings were found in 30% of the patients who received misoprostol and in 19% of the patients who received extra-amniotic saline solution infusion (relative risk, 1.6; 95% CI, 1.0-2.4; P =.05). There was more tachysystole in the misoprostol group (8%) than in the extra-amniotic saline solution infusion group (1%; P =.02). There were no differences in the routes of deliveries or neonatal outcomes between groups.

CONCLUSION

Extra-amniotic saline solution infusion with oxytocin administration appears more effective and is associated with fewer maternal complications than misoprostol for cervical ripening and labor induction.

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

OBJECTIVE

The purpose of this study was to compare the efficacy of 3 different techniques of cervical ripening and induction.

STUDY DESIGN

Patients who required cervical ripening and induction were randomized to one of 3 groups: (1) supracervical Foley catheter and intravaginal dinoprostone gel, (2) supracervical Foley catheter and 100 microg oral doses of misoprostol, or (3) serial 100-microg oral doses of misoprostol. Intravenous oxytocin was administered when a protraction disorder of labor was identified.

RESULTS

There were 339 women randomized. There was no significant difference in the time from first intervention to delivery in the 3 groups (P =.546). In each group, a similar percentage of women required oxytocin (P =.103). The rates of cesarean delivery were equivalent among the groups (P =.722). Rates of tachysystole were high but statistically equivalent among the 3 groups. There were no significant differences in Apgar scores or umbilical artery pH.

CONCLUSION

Oral 100 microg serial doses of misoprostol, with or without the use of a supracervical Foley catheter, were equivalent to the use of a supracervical Foley catheter and serial 4-mg doses of dinoprostone gel for cervical ripening and the induction of labor.

Induction of labour with misoprostol

Misoprostol, an orally active prostaglandin E1 analogue, has been used widely by the vaginal and oral routes for labour induction at or near term. Several recent trials have confirmed that it is highly effective. Overall caesarean section rates appear to be reduced, despite a relative increase in caesarean sections for fetal heart rate abnormalities. Concern remains regarding increased rates of uterine hyperstimulation and meconium-stained amniotic fluid, although data on perinatal outcomes have been reassuring. Recent reports reviewed here have raised the possibility that postpartum haemorrhage may be increased after the induction of labour with misoprostol, and isolated reports of uterine rupture with or without previous caesarean section, continue to appear. Using small dosages appears to reduce adverse outcomes. Very large trials are needed to evaluate rare adverse outcomes.

Mechanical methods for induction of labour

BACKGROUND

Mechanical methods were the first methods developed to ripen the cervix or to induce labour. Devices which were used include various type of catheters and of laminaria tents, introduced into the cervical canal or into the extra-amniotic space. Mechanical methods were never completely abandoned, but were substituted by pharmacological methods during recent decades. Potential advantages of mechanical methods, compared with pharmacological methods, may include simplicity of preservation, lower cost and reduction of the side effects. However, special attention should be paid to contraindications (e.g. low-lying placenta), risk of infection and maternal discomfort when inserting these devices. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

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, intracervical, misoprostol) and oxytocin.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched April 2001.

SELECTION CRITERIA

The criteria for inclusion were the following: (1) clinical trials comparing mechanical methods used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate or unclear method for allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data will be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman.

MAIN RESULTS

In total, 58 studies were considered; 45 studies have been included and 13 were excluded. Studies generally included women with unfavourable cervix and intact membranes. Comparing mechanical methods with placebo/no treatment, only one study with 48 participants reported on vaginal delivery not achieved in 24 hours (69% with mechanical methods versus 77% with placebo/no treatment; relative risk (RR) 0.90; 95% confidence interval (CI): 0.64-1.26). Hyperstimulation with fetal heart rate changes was not reported. The risk of caesarean section, reported in six studies including 416 women, was similar between groups (34%; RR 1.00; 95% CI: 0.76-1.30). There were no reported cases of severe neonatal and maternal morbidity. Comparing mechanical methods with vaginal PGE2, only one trial (109 women) reported on vaginal delivery not achieved in 24 hours (73% versus 42%; relative risk (RR) 1.74; 95% CI: 1.21-2.49). Compared with intracervical PGE2, only one trial (100 women) reported on vaginal delivery not achieved in 24 hours (68% versus 40%; relative risk (RR) 1.70; 95% CI: 1.15-2.51). Compared with with misoprostol, the effectiveness of mechanical methods was similar (34% versus 30%; relative risk (RR) 1.15; 95% CI: 0.80-1.66). The use of mechanical method reduced the risk of hyperstimulation with fetal heart rate changes when compared with prostaglandins: vaginal PGE2 (0% versus 6%; RR 0.14; 95% CI: 0.04-0.53), intracervical PGE2 (0% versus 1%; RR 0.21; 95% CI: 0.04-1.20) and misoprostol (4% versus 9%; RR 0.41; 95% CI: 0.20-0.87). There was no difference in the risk of caesarean section between mechanical methods and prostaglandins. Serious neonatal (three cases) and maternal morbidity (one case) were infrequently reported. When compared with oxytocin, use of mechanical methods reduced the risk of caesarean section (4 trials; 198 women; 17% versus 32%; RR 0.55; 95% CI: 0.33-0.91). The likelihood of vaginal delivery in 24 hours and of hyperstimulation with fetal heart rate changes was not reported. There were no reported cases of serious maternal morbidity and severe neonatal morbidity was not reported. These results are similar whatever specific mechanical method was used, except with extra-amniotic infusion. When comparing extra-amniotic infusion with any prostaglandins, women were more likely to not achieve vaginal delivery within 24 hours (57% versus 42%; RR 1.33; 95% CI: 1.02-1.75), the risk of caesarean section was increased (31% versus 22%; RR 1.48; 95% CI: 1.14-1.90), without a reduction of the risk of hyperstimulation.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to evaluate the effectiveness, in terms of likelihood of vaginal delivery in 24 hours, of mechanical methods compared with placebo/no treatment or with prostaglandins. The risk of hyperstimulation was reduced when compared with prostaglandins (intracervical, intravaginal or misoprostol). Compared to oxytocin in women with unfavourable cervix, mechanical methods reduce the risk of caesarean section. There is no evidence to support the use of extra-amniotic infusion.