Intravaginal misoprostol versus Foley catheter for cervical ripening and induction of labor

Mechanical methods for induction of labour

BACKGROUND

Mechanical methods were the first methods developed to ripen the cervix and induce labour. During recent decades they have been substituted by pharmacological methods. Potential advantages of mechanical methods, compared with pharmacological methods may include reduction in side effects that could improve neonatal outcomes. This is an update of a review first published in 2001, last updated in 2012.

OBJECTIVES

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

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies (9 January 2018). We updated the search in March 2019 and added the search results to the awaiting classification section of the review.

SELECTION CRITERIA

Clinical trials comparing mechanical methods used for third trimester cervical ripening or labour induction with pharmacological methods. Mechanical methods include: (1) the introduction of a catheter through the cervix into the extra-amniotic space with balloon insufflation; (2) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (3) use of a catheter to inject fluid into the extra-amniotic space (EASI). This review includes the following comparisons: (1) specific mechanical methods (balloon catheter, laminaria tents or EASI) compared with prostaglandins (different types, different routes) or with oxytocin; (2) single balloon compared to a double balloon; (3) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins or oxytocin alone.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparing the effects of vaginal misoprostol, laminaria, and extra amniotic saline infusion on cervical ripening and induction of labor

OBJECTIVE

This study aimed to compare the effects of vaginal misoprostol, laminaria, and extra-amniotic saline infusion (EASI) on cervical ripening.

METHODS

This randomized controlled trial was conducted on 195 women with singleton pregnancies and unripe cervices. Participants were randomly allocated to 3, 65-person groups: a misoprostol, a laminaria, and an EASI group. The interventions in the misoprostol, laminaria, and EASI groups included a single 25-µg vaginal misoprostol suppository, an intracervical laminaria, and a transcervical Foley catheter, respectively. The groups were compared with each other regarding time intervals from labor induction to labor active phase and delivery, cervical dilation, Bishop scores 6 hours after induction, delivery type, length of hospital stay, and complications.

RESULTS

There were no significant differences among the groups regarding maternal ages, gestational ages, body mass indices, baseline cervical dilations, and Bishop scores (P>0.05). Six hours after induction, the Bishop score and cervical dilation were significantly greater in the EASI group than in the other 2 groups (P<0.001). Moreover, time intervals from labor induction to labor active phase and delivery in the EASI group were significantly short (P<0.001). The rates of cesarean section, fetal distress, placental abruption, and meconium staining in the misoprostol group were significantly high (P<0.05), and the length of hospital stay in the EASI group was significantly short (P<0.001).

CONCLUSION

EASI is a safer and more effective method for cervical ripening. Considering its inexpensiveness, easy accessibility, and greater effectiveness, EASI is recommended for cervical ripening.

TRIAL REGISTRATION

Iranian Center for Clinical Trials Identifier: IRCT20170513033941N39.

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.

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

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

Induction of labour

OBJECTIVE

To review the most current literature in order to provide evidence-based recommendations to obstetrical care providers on induction of labour.

OPTIONS

Intervention in a pregnancy with induction of labour.

OUTCOMES

Appropriate timing and method of induction, appropriate mode of delivery, and optimal maternal and perinatal outcomes.

EVIDENCE

Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in 2010 using appropriate controlled vocabulary (e.g., labour, induced, labour induction, cervical ripening) and key words (e.g., induce, induction, augmentation). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to the end of 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence in this document was rated using criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). SUMMARY STATEMENTS: 1. Prostaglandins E(2) (cervical and vaginal) are effective agents of cervical ripening and induction of labour for an unfavourable cervix. (I) 2. Intravaginal prostaglandins E(2) are preferred to intracervical prostaglandins E(2) because they results in more timely vaginal deliveries. (I).

Cervical ripening and induction of labour-awareness, knowledge and perception of antenatal attendees in Ibadan, Nigeria

The levels of awareness, knowledge and the perceptions of women about cervical ripening and induction of labour were assessed in a cross-sectional questionnaire-based interview of 265 antenatal attendees of the University College Hospital, Ibadan, Nigeria from 1 March to 30 April 2009. Questions included evaluated sociodemographic data, obstetric history, awareness of both procedures and knowledge of specific methods. Data analysis was done using SPSS v.14.0 for Windows; frequency tables were utilised to determine proportions and significant variables from χ(2) analysis were entered into a logistic regression model. The majority of respondents were between 26 and 34 years; 56.4% were nulliparous. Awareness of cervical ripening and induction of labour was found in 71% of respondents. Knowledge of misoprostol and Foley's catheter however, was present in 25% and 13% of all women, respectively. Both procedures were perceived to prevent caesarean section or reduce burden of health workers in 16% of respondents. No significant predictor of knowledge was found but history of previous induction was a predictor of awareness (p < 0.05). Improved counselling is required to further increase knowledge of methods for induction and correct wrong perceptions, particularly in women at risk of labour induction.

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.

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.

Comparison of induction of labor with vaginal misoprostol plus oxytocin versus oxytocin alone in term primigravidae

OBJECTIVE

To compare the efficacy and complications of intravaginal misoprostol application before starting oxytocin infusion with oxytocin infusion alone for labor induction in term primigravidae pregnancies with low-Bishop score.

METHODS

This randomized study included 101 primigravidae women with singleton pregnancies >38 weeks and a Bishop score of <6. Group 1 (50 patients) received a 50-μg dose of intravaginal misoprostol, with an oxytocin infusion started 3 h later. Group 2 (51 patients) received only an oxytocin infusion for labor induction. The time from induction to delivery, the route of delivery and complications were analyzed.

RESULTS

The mean time from induction to delivery was 10.4 ± 2.1 h in Group 1 and 13.7 ± 3.4 in Group 2 (p < 0.001). The rates of vaginal delivery, Apgar scores at 1st and 5th min, placental abruption, and postpartum hemorrhage were similar between the two groups.

CONCLUSION

Intravaginal application of 50-μg misoprostol before starting oxytocin infusion is a more effective method of labor induction than oxytocin infusion alone in term primigravidae pregnant women with low-Bishop scores.

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.

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

OBJECTIVE

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

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level Swedish hospital.

POPULATION

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

METHODS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

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

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

Cervical ripening with the Foley catheter

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Mechanical Methods of Cervical Ripening and Labor Induction

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

Uterine rupture

PURPOSE OF REVIEW

The increasing rates of primary caesarean section are likely to contribute to a rise in the incidence of uterine rupture in developed countries. Uterine rupture continues to be an important cause of maternal death in less and least developed countries. Recent publications adressing the diagnosis, aetiology and management of primary caesarian section are reviewed.

RECENT FINDINGS

Uterine rupture is commonly associated with vaginal birth after caesarean section, although the absolute risk varies according to previous obstetric history, gestational age, and induction of labour. Quantification of risk for a range of circumstances allows informed counselling of pregnant women. Imaging techniques may improve the early detection of uterine dehiscence but in the acute setting abnormal fetal heart rate patterns provide early diagnostic information. The scale of the problem in less and least developed countries is sobering and maternal mortality can be determined by the ability to access basic obstetric care.

SUMMARY

Uterine rupture remains one of the most frightening complications in obstetric care. The risk of its occurrence is likely to increase for many parous women, placing the emphasis on counselling and early prediction and prevention wherever possible.