Management of pregnancies beyond forty-one weeks' gestation with an unfavorable cervix

Outpatient cervical ripening and labor induction with low-dose vaginal misoprostol reduces the interval to delivery: a systematic review and network meta-analysis

OBJECTIVE

Several systematic reviews and meta-analyses have summarized the evidence on the efficacy and safety of various outpatient cervical ripening methods. However, the method with the highest efficacy and safety profile has not been determined conclusively. We performed a systematic review and network meta-analysis of published randomized controlled trials to assess the efficacy and safety of cervical ripening methods currently employed in the outpatient setting.

DATA SOURCES

With the assistance of an experienced medical librarian, we performed a systematic search of the literature using MEDLINE, Embase, Scopus, Web of Science, Cochrane Library, and ClinicalTrials.gov. We systematically searched electronic databases from inception to January 14, 2020.

STUDY ELIGIBILITY CRITERIA

We considered randomized controlled trials comparing a variety of methods for outpatient cervical ripening.

METHODS

We conducted a frequentist random effects network meta-analysis employing data from randomized controlled trials. We performed a direct, pairwise meta-analysis to compare the efficacy of various outpatient cervical ripening methods, including placebo. We employed ranking strategies to determine the most efficacious method using the surface under the cumulative ranking curve; a higher surface under the cumulative ranking curve value implied a more efficacious method. We assessed the following outcomes: time from intervention to delivery, cesarean delivery rates, changes in the Bishop score, need for additional ripening methods, incidence of Apgar scores <7 at 5 minutes, and uterine hyperstimulation.

RESULTS

We included data from 42 randomized controlled trials including 6093 participants. When assessing the efficacy of all methods, 25 μg vaginal misoprostol was the most efficacious in reducing the time from intervention to delivery (surface under the cumulative ranking curve of 1.0) without increasing the odds of cesarean delivery, the need for additional ripening methods, the incidence of a low Apgar score, or uterine hyperstimulation. Acupressure (surface under the cumulative ranking curve of 0.3) and primrose oil (surface under the cumulative ranking curve of 0.2) were the least effective methods in reducing the time to delivery interval. Among effective methods, 50 mg oral mifepristone was associated with the lowest odds of cesarean delivery (surface under the cumulative ranking curve of 0.9).

CONCLUSION

When balancing efficacy and safety, vaginal misoprostol 25 μg represents the best method for outpatient cervical ripening.

Twice-Weekly Versus Once-Weekly Membrane Sweeping in the Prevention of Post-Term Pregnancy: a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Membrane sweeping is considered a simple and effective method for initiating spontaneous onset of labor. Despite the widely accepted membrane sweeping use to prevent post-term birth, the optimal frequency has not been estimated. We aimed to assess the effectiveness and safety of twice-weekly versus once-weekly membrane sweeping in post-term pregnancy prevention. Four different databases were searched for available clinical trials from inception to October 2022. We selected randomized controlled trials (RCTs) that compared twice-weekly membrane sweeping in intervention group versus once-weekly membrane sweeping in control group among pregnant women with singleton pregnancy at ≥ 39 gestational weeks. Our primary outcomes were the rate of spontaneous onset of labor and the requirement for formal methods of labor induction. Our secondary outcomes were sweeping to delivery interval in days, gestational age at delivery in weeks, Bishop score at admission, chorioamnionitis, and premature rupture of membranes. Three RCTs (596 patients) were included. Twice-weekly membrane sweeping was associated with significant increase in the rate of spontaneous onset of labor and significant decline in labor induction rate in comparison with once-weekly group. Duration from sweeping to delivery was significantly shorter among the twice-weekly group (p<0.001). Furthermore, gestational age at delivery was significantly earlier in the twice-weekly group. A significantly higher Bishop score at admission was observed in the twice-weekly group (p=0.02). There were no significant differences across both groups in chorioamnionitis and premature rupture of membranes. In conclusion, twice-weekly membrane sweeping is more effective in preventing post-maturity pregnancy than once-weekly sweeping without added adverse events.

Outpatient Cervical Ripening: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the comparative effectiveness and potential harms of cervical ripening in the outpatient compared with the inpatient setting, or different methods of ripening in the outpatient setting alone.

DATA SOURCES

Searches for articles in English included MEDLINE, EMBASE, CINAHL, Cochrane Library, ClinicalTrials.gov, and reference lists (up to August 2020).

METHODS OF STUDY SELECTION

Using predefined criteria and DistillerSR software, 10,853 citations were dual-reviewed for randomized controlled trials (RCTs) and cohort studies of outpatient cervical ripening using prostaglandins and mechanical methods in pregnant women at or beyond 37 weeks of gestation.

TABULATION, INTEGRATION, AND RESULTS

Using prespecified criteria, study data abstraction and risk of bias assessment were conducted by two reviewers, random-effects meta-analyses were conducted and strength of evidence was assessed. We included 30 RCTs and 10 cohort studies (N=9,618) most generalizable to women aged 25-30 years with low-risk pregnancies. All findings were low or insufficient strength of evidence and not statistically significant. Incidence of cesarean delivery was not different for any comparison of inpatient and outpatient settings, or comparisons of different methods in the outpatient setting (most evidence available for single-balloon catheters and dinoprostone). Harms were inconsistently reported or inadequately defined. Differences were not found for neonatal infection (eg, sepsis) with outpatient compared with inpatient dinoprostone, birth trauma (eg, cephalohematoma) with outpatient compared with inpatient single-balloon catheter, shoulder dystocia with outpatient dinoprostone compared with placebo, maternal infection (eg, chorioamnionitis) with outpatient compared with inpatient single-balloon catheters or outpatient prostaglandins compared with placebo, and postpartum hemorrhage with outpatient catheter compared with inpatient dinoprostone. Evidence on misoprostol, hygroscopic dilators, and other outcomes (eg, perinatal mortality and time to vaginal birth) was insufficient.

CONCLUSION

In women with low-risk pregnancies, outpatient cervical ripening with dinoprostone or single-balloon catheters did not increase cesarean deliveries. Although there were no clear differences in harms when comparing outpatient with inpatient cervical ripening, the certainty of evidence is low or insufficient to draw definitive conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020167406.

Induction of labour at or beyond 37 weeks' gestation

BACKGROUND

Risks of stillbirth or neonatal death increase as gestation continues beyond term (around 40 weeks' gestation). It is unclear whether a policy of labour induction can reduce these risks. This Cochrane Review is an update of a review that was originally published in 2006 and subsequently updated in 2012 and 2018.

OBJECTIVES

To assess the effects of a policy of labour induction at or beyond 37 weeks' gestation compared with a policy of awaiting spontaneous labour indefinitely (or until a later gestational age, or until a maternal or fetal indication for induction of labour arises) on pregnancy outcomes for the infant and the mother.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (17 July 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women at or beyond 37 weeks, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in abstract form only. Cluster-RCTs, quasi-RCTs and trials using a cross-over design were not eligible for inclusion in this review. We included pregnant women at or beyond 37 weeks' gestation. Since risk factors at this stage of pregnancy would normally require intervention, only trials including women at low risk for complications, as defined by trialists, were eligible. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

In this updated review, we included 34 RCTs (reporting on over 21,000 women and infants) mostly conducted in high-income settings. The trials compared a policy to induce labour usually after 41 completed weeks of gestation (> 287 days) with waiting for labour to start and/or waiting for a period before inducing labour. The trials were generally at low to moderate risk of bias. Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.15 to 0.64; 22 trials, 18,795 infants; high-certainty evidence). There were four perinatal deaths in the labour induction policy group compared with 25 perinatal deaths in the expectant management group. The number needed to treat for an additional beneficial outcome (NNTB) with induction of labour, in order to prevent one perinatal death, was 544 (95% CI 441 to 1042). There were also fewer stillbirths in the induction group (RR 0.30, 95% CI 0.12 to 0.75; 22 trials, 18,795 infants; high-certainty evidence); two in the induction policy group and 16 in the expectant management group. For women in the policy of induction arms of trials, there were probably fewer caesarean sections compared with expectant management (RR 0.90, 95% CI 0.85 to 0.95; 31 trials, 21,030 women; moderate-certainty evidence); and probably little or no difference in operative vaginal births with induction (RR 1.03, 95% CI 0.96 to 1.10; 22 trials, 18,584 women; moderate-certainty evidence). Induction may make little or difference to perineal trauma (severe perineal tear: RR 1.04, 95% CI 0.85 to 1.26; 5 trials; 11,589 women; low-certainty evidence). Induction probably makes little or no difference to postpartum haemorrhage (RR 1.02, 95% CI 0.91 to 1.15, 9 trials; 12,609 women; moderate-certainty evidence), or breastfeeding at discharge (RR 1.00, 95% CI 0.96 to 1.04; 2 trials, 7487 women; moderate-certainty evidence). Very low certainty evidence means that we are uncertain about the effect of induction or expectant management on the length of maternal hospital stay (average mean difference (MD) -0.19 days, 95% CI -0.56 to 0.18; 7 trials; 4120 women; Tau² = 0.20; I² = 94%). Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.80 to 0.96; 17 trials, 17,826 infants; high-certainty evidence), and probably fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.73, 95% CI 0.56 to 0.96; 20 trials, 18,345 infants; moderate-certainty evidence). Induction or expectant management may make little or no difference for neonatal encephalopathy (RR 0.69, 95% CI 0.37 to 1.31; 2 trials, 8851 infants; low-certainty evidence, and probably makes little or no difference for neonatal trauma (RR 0.97, 95% CI 0.63 to 1.49; 5 trials, 13,106 infants; moderate-certainty evidence) for induction compared with expectant management. Neurodevelopment at childhood follow-up and postnatal depression were not reported by any trials. In subgroup analyses, no differences were seen for timing of induction (< 40 versus 40-41 versus > 41 weeks' gestation), by parity (primiparous versus multiparous) or state of cervix for any of the main outcomes (perinatal death, stillbirth, NICU admission, caesarean section, operative vaginal birth, or perineal trauma).

AUTHORS' CONCLUSIONS

There is a clear reduction in perinatal death with a policy of labour induction at or beyond 37 weeks compared with expectant management, though absolute rates are small (0.4 versus 3 deaths per 1000). There were also lower caesarean rates without increasing rates of operative vaginal births and there were fewer NICU admissions with a policy of induction. Most of the important outcomes assessed using GRADE had high- or moderate-certainty ratings. While existing trials have not yet reported on childhood neurodevelopment, this is an important area for future research. The optimal timing of offering induction of labour to women at or beyond 37 weeks' gestation needs further investigation, as does further exploration of risk profiles of women and their values and preferences. Offering women tailored counselling may help them make an informed choice between induction of labour for pregnancies, particularly those continuing beyond 41 weeks - or waiting for labour to start and/or waiting before inducing labour.

Membrane sweeping for induction of labour

BACKGROUND

Induction of labour involves stimulating uterine contractions artificially to promote the onset of labour. There are several pharmacological, surgical and mechanical methods used to induce labour. Membrane sweeping is a mechanical technique whereby a clinician inserts one or two fingers into the cervix and using a continuous circular sweeping motion detaches the inferior pole of the membranes from the lower uterine segment. This produces hormones that encourage effacement and dilatation potentially promoting labour. This review is an update to a review first published in 2005.

OBJECTIVES

To assess the effects and safety of membrane sweeping for induction of labour in women at or near term (≥ 36 weeks' gestation).

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (25 February 2019), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (25 February 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing membrane sweeping used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed on a predefined list of labour induction methods. Cluster-randomised trials were eligible, but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, risk of bias and extracted data. Data were checked for accuracy. Disagreements were resolved by discussion, or by including a third review author. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 44 studies (20 new to this update), reporting data for 6940 women and their infants. We used random-effects throughout. Overall, the risk of bias was assessed as low or unclear risk in most domains across studies. Evidence certainty, assessed using GRADE, was found to be generally low, mainly due to study design, inconsistency and imprecision. Six studies (n = 1284) compared membrane sweeping with more than one intervention and were thus included in more than one comparison. No trials reported on the outcomes uterine hyperstimulation with/without fetal heart rate (FHR) change, uterine rupture or neonatal encephalopathy. Forty studies (6548 participants) compared membrane sweeping with no treatment/sham Women randomised to membrane sweeping may be more likely to experience: · spontaneous onset of labour (average risk ratio (aRR) 1.21, 95% confidence interval (CI) 1.08 to 1.34, 17 studies, 3170 participants, low-certainty evidence). but less likely to experience: · induction (aRR 0.73, 95% CI 0.56 to 0.94, 16 studies, 3224 participants, low-certainty evidence); There may be little to no difference between groups for: · caesareans (aRR 0.94, 95% CI 0.85 to 1.04, 32 studies, 5499 participants, moderate-certainty evidence); · spontaneous vaginal birth (aRR 1.03, 95% CI 0.99 to 1.07, 26 studies, 4538 participants, moderate-certainty evidence); · maternal death or serious morbidity (aRR 0.83, 95% CI 0.57 to 1.20, 17 studies, 2749 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.83, 95% CI 0.59 to 1.17, 18 studies, 3696 participants, low-certainty evidence). Four studies reported data for 480 women comparing membrane sweeping with vaginal/intracervical prostaglandins There may be little to no difference between groups for the outcomes: · spontaneous onset of labour (aRR, 1.24, 95% CI 0.98 to 1.57, 3 studies, 339 participants, low-certainty evidence); · induction (aRR 0.90, 95% CI 0.56 to 1.45, 2 studies, 157 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.44 to 1.09, 3 studies, 339 participants, low-certainty evidence); · spontaneous vaginal birth (aRR 1.12, 95% CI 0.95 to 1.32, 2 studies, 252 participants, low-certainty evidence); · maternal death or serious morbidity (aRR 0.93, 95% CI 0.27 to 3.21, 1 study, 87 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.40, 95% CI 0.12 to 1.33, 2 studies, 269 participants, low-certainty evidence). One study, reported data for 104 women, comparing membrane sweeping with intravenous oxytocin +/- amniotomy There may be little to no difference between groups for: · spontaneous onset of labour (aRR 1.32, 95% CI 88 to 1.96, 1 study, 69 participants, low-certainty evidence); · induction (aRR 0.51, 95% CI 0.05 to 5.42, 1 study, 69 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.12 to 3.85, 1 study, 69 participants, low-certainty evidence); · maternal death or serious morbidity was reported on, but there were no events. Two studies providing data for 160 women compared membrane sweeping with vaginal/oral misoprostol There may be little to no difference between groups for: · caesareans (RR 0.82, 95% CI 0.31 to 2.17, 1 study, 96 participants, low-certainty evidence). One study providing data for 355 women which compared once weekly membrane sweep with twice-weekly membrane sweep and a sham procedure There may be little to no difference between groups for: · induction (RR 1.19, 95% CI 0.76 to 1.85, 1 study, 234 participants, low-certainty); · caesareans (RR 0.93, 95% CI 0.60 to 1.46, 1 study, 234 participants, low-certainty evidence); · spontaneous vaginal birth (RR 1.00, 95% CI 0.86 to 1.17, 1 study, 234 participants, moderate-certainty evidence); · maternal death or serious maternal morbidity (RR 0.78, 95% CI 0.30 to 2.02, 1 study, 234 participants, low-certainty evidence); · neonatal death or serious neonatal perinatal morbidity (RR 2.00, 95% CI 0.18 to 21.76, 1 study, 234 participants, low-certainty evidence); We found no studies that compared membrane sweeping with amniotomy only or mechanical methods. Three studies, providing data for 675 women, reported that women indicated favourably on their experience of membrane sweeping with one study reporting that 88% (n = 312) of women questioned in the postnatal period would choose membrane sweeping in the next pregnancy. Two studies reporting data for 290 women reported that membrane sweeping is more cost-effective than using prostaglandins, although more research should be undertaken in this area.

AUTHORS' CONCLUSIONS

Membrane sweeping may be effective in achieving a spontaneous onset of labour, but the evidence for this was of low certainty. When compared to expectant management, it potentially reduces the incidence of formal induction of labour. Questions remain as to whether there is an optimal number of membrane sweeps and timings and gestation of these to facilitate induction of labour.

Induction of labour for improving birth outcomes for women at or beyond term

BACKGROUND

Beyond term, the risks of stillbirth or neonatal death increase. It is unclear whether a policy of labour induction can reduce these risks. This Cochrane review is an update of a review that was originally published in 2006 and subsequently updated in 2012 OBJECTIVES: To assess the effects of a policy of labour induction at or beyond term compared with a policy of awaiting spontaneous labour or until an indication for birth induction of labour is identified) on pregnancy outcomes for infant and mother.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (9 October 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women at or beyond term, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in abstract form only. Cluster-RCTs, quasi-RCTs and trials using a cross-over design are not eligible for inclusion in this review.We included pregnant women at or beyond term. Since a risk factor at this stage of pregnancy would normally require an intervention, only trials including women at low risk for complications were eligible. We accepted the trialists' definition of 'low risk'. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane review.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

In this updated review, we included 30 RCTs (reporting on 12,479 women). The trials took place in Norway, China, Thailand, the USA, Austria, Turkey, Canada, UK, India, Tunisia, Finland, Spain, Sweden and the Netherlands. They were generally at a moderate risk of bias.Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.14 to 0.78; 20 trials, 9960 infants; moderate-quality evidence). There were two perinatal deaths in the labour induction policy group compared with 16 perinatal deaths in the expectant management group. The number needed to treat to for an additional beneficial outcome (NNTB) with induction of labour in order to prevent one perinatal death was 426 (95% CI 338 to 1337). There were fewer stillbirths in the induction group (RR 0.33, 95% CI 0.11 to 0.96; 20 trials, 9960 infants; moderate-quality evidence); there was one stillbirth in the induction policy arm and 10 in the expectant management group.For women in the policy of induction arms of trials, there were fewer caesarean sections compared with expectant management (RR 0.92, 95% CI 0.85 to 0.99; 27 trials, 11,738 women; moderate-quality evidence); and a corresponding marginal increase in operative vaginal births with induction (RR 1.07, 95% CI 0.99 to 1.16; 18 trials, 9281 women; moderate-quality evidence). There was no evidence of a difference between groups for perineal trauma (RR 1.09, 95% CI 0.65 to 1.83; 4 trials; 3028 women; low-quality evidence), postpartum haemorrhage (RR 1.09 95% CI 0.92 to 1.30, 5 trials; 3315 women; low-quality evidence), or length of maternal hospital stay (average mean difference (MD) -0.34 days, 95% CI -1.00 to 0.33; 5 trials; 1146 women; Tau² = 0.49; I² 95%; very low-quality evidence).Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.77 to 1.01; 13 trials, 8531 infants; moderate-quality evidence) and fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.70, 95% CI 0.50 to 0.98; 16 trials, 9047 infants; moderate-quality evidence).There was no evidence of a difference for neonatal trauma (RR 1.18, 95% CI 0.68 to 2.05; 3 trials, 4255 infants; low-quality evidence), for induction compared with expectant management.Neonatal encephalopathy, neurodevelopment at childhood follow-up, breastfeeding at discharge and postnatal depression were not reported by any trials.In subgroup analyses, no clear differences between timing of induction (< 41 weeks versus ≥ 41 weeks' gestation) or by state of cervix were seen for perinatal death, stillbirth, NICU admission, caesarean section, or perineal trauma. However, operative vaginal birth was more common in the inductions at < 41 weeks' gestation subgroup compared with inductions at later gestational ages. The majority of trials (about 75% of participants) adopted a policy of induction at ≥ 41 weeks (> 287 days) gestation for the intervention arm.

AUTHORS' CONCLUSIONS

A policy of labour induction at or beyond term compared with expectant management is associated with fewer perinatal deaths and fewer caesarean sections; but more operative vaginal births. NICU admissions were lower and fewer babies had low Apgar scores with induction. No important differences were seen for most of the other maternal and infant outcomes.Most of the important outcomes assessed using GRADE had a rating of moderate or low-quality evidence - with downgrading decisions generally due to study limitations such as lack of blinding (a condition inherent in comparisons between a policy of acting and of waiting), or imprecise effect estimates. One outcome (length of maternal stay) was downgraded further to very low-quality evidence due to inconsistency.Although the absolute risk of perinatal death is small, it may be helpful to offer women appropriate counselling to help choose between scheduled induction for a post-term pregnancy or monitoring without (or later) induction).The optimal timing of offering induction of labour to women at or beyond term warrants further investigation, as does further exploration of risk profiles of women and their values and preferences. Individual participant meta-analysis is likely to help elucidate the role of factors, such as parity, in influencing outcomes of induction compared with expectant management.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

FUTURE WORK

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

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Pharmacological and mechanical interventions for labour induction in outpatient settings

BACKGROUND

Induction of labour is carried out for a variety of indications and using a range of methods. For women at low risk of pregnancy complications, some methods of induction of labour or cervical ripening may be suitable for use in outpatient settings.

OBJECTIVES

To examine pharmacological and mechanical interventions to induce labour or ripen the cervix in outpatient settings in terms of effectiveness, maternal satisfaction, healthcare costs and, where information is available, safety.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining outpatient cervical ripening or induction of labour with pharmacological agents or mechanical methods. Cluster trials were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed evidence using the GRADE approach.

MAIN RESULTS

This updated review included 34 studies of 11 different methods for labour induction with 5003 randomised women, where women received treatment at home or were sent home after initial treatment and monitoring in hospital.Studies examined vaginal and intracervical prostaglandin E₂ (PGE₂), vaginal and oral misoprostol, isosorbide mononitrate, mifepristone, oestrogens, amniotomy and acupuncture, compared with placebo, no treatment, or routine care. Trials generally recruited healthy women with a term pregnancy. The risk of bias was mostly low or unclear, however, in 16 trials blinding was unclear or not attempted. In general, limited data were available on the review's main and additional outcomes. Evidence was graded low to moderate quality. 1. Vaginal PGE₂ versus expectant management or placebo (5 studies)Fewer women in the vaginal PGE₂ group needed additional induction agents to induce labour, however, confidence intervals were wide (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.27 to 0.99; 150 women; 2 trials). There were no clear differences between groups in uterine hyperstimulation (with or without fetal heart rate (FHR) changes) (RR 3.76, 95% CI 0.64 to 22.24; 244 women; 4 studies; low-quality evidence), caesarean section (RR 0.80, 95% CI 0.49 to 1.31; 288 women; 4 studies; low-quality evidence), or admission to a neonatal intensive care unit (NICU) (RR 0.32, 95% CI 0.10 to 1.03; 230 infants; 3 studies; low-quality evidence).There was no information on vaginal birth within 24, 48 or 72 hours, length of hospital stay, use of emergency services or maternal or caregiver satisfaction. Serious maternal and neonatal morbidity or deaths were not reported. 2. Intracervical PGE₂ versus expectant management or placebo (7 studies) There was no clear difference between women receiving intracervical PGE₂ and no treatment or placebo in terms of need for additional induction agents (RR 0.98, 95% CI 0.74 to 1.32; 445 women; 3 studies), vaginal birth not achieved within 48 to 72 hours (RR 0.83, 95% CI 0.68 to 1.02; 43 women; 1 study; low-quality evidence), uterine hyperstimulation (with FHR changes) (RR 2.66, 95% CI 0.63 to 11.25; 488 women; 4 studies; low-quality evidence), caesarean section (RR 0.90, 95% CI 0.72 to 1.12; 674 women; 7 studies; moderate-quality evidence), or babies admitted to NICU (RR 1.61, 95% CI 0.43 to 6.05; 215 infants; 3 studies; low-quality evidence). There were no uterine ruptures in either the PGE₂ group or placebo group.There was no information on vaginal birth not achieved within 24 hours, length of hospital stay, use of emergency services, mother or caregiver satisfaction, or serious morbidity or neonatal morbidity or perinatal death. 3. Vaginal misoprostol versus placebo (4 studies)One small study reported on the rate of perinatal death with no clear differences between groups; there were no deaths in the treatment group compared with one stillbirth (reason not reported) in the control group (RR 0.34, 95% CI 0.01 to 8.14; 77 infants; 1 study; low-quality evidence).There was no clear difference between groups in rates of uterine hyperstimulation with FHR changes (RR 1.97, 95% CI 0.43 to 9.00; 265 women; 3 studies; low-quality evidence), caesarean section (RR 0.94, 95% CI 0.61 to 1.46; 325 women; 4 studies; low-quality evidence), and babies admitted to NICU (RR 0.89, 95% CI 0.54 to 1.47; 325 infants; 4 studies; low-quality evidence).There was no information on vaginal birth not achieved within 24, 48 or 72 hours, additional induction agents required, length of hospital stay, use of emergency services, mother or caregiver satisfaction, serious maternal, and other neonatal, morbidity or death.No substantive differences were found for other comparisons. One small study found that women who received oral misoprostol were more likely to give birth within 24 hours (RR 0.65, 95% CI 0.48 to 0.86; 87 women; 1 study) and were less likely to require additional induction agents (RR 0.60, 95% CI 0.37 to 0.97; 127 women; 2 studies). Women who received mifepristone were also less likely to require additional induction agents (average RR 0.59, 95% CI 0.37 to 0.95; 311 women; 4 studies; I² = 74%); however, this result should be interpreted with caution due to high heterogeneity. One trial each of acupuncture and outpatient amniotomy were included, but few review outcomes were reported.

AUTHORS' CONCLUSIONS

Induction of labour in outpatient settings appears feasible and important adverse events seem rare, however, in general there is insufficient evidence to detect differences. There was no strong evidence that agents used to induce labour in outpatient settings had an impact (positive or negative) on maternal or neonatal health. There was some evidence that compared to placebo or no treatment, induction agents administered on an outpatient basis reduced the need for further interventions to induce labour, and shortened the interval from intervention to birth.We do not have sufficient evidence to know which induction methods are preferred by women, the interventions that are most effective and safe to use in outpatient settings, or their cost effectiveness. Further studies where various women-friendly outpatient protocols are compared head-to-head are required. As part of such work, women should be consulted on what sort of management they would prefer.

Factors associated with vaginal delivery in hypertensive and normotensive pregnant women submitted to labor induction with misoprostol: a cohort study

OBJECTIVE

To determine the factors associated with vaginal delivery in hypertensive and normotensive pregnant women submitted to induction of labor with misoprostol.

METHODS

A cohort study.

RESULTS

The factors associated with vaginal delivery in both normotensive and hypertensive women were, respectively, Bishop score ≥ 4 (OR = 1.87; 95% CI: 1.06-3.29; p = 0.03) and (OR = 2.31; 95% CI: 1.25-4.28; p = 0.008) and parity ≥ 1 (OR = 4.36; 95% CI: 2.16-8.80; p < 0.0001) and (OR = 2.61; 95% CI: 1.36-5.04; p = 0.004).

CONCLUSION

The factors associated with vaginal delivery were Bishop score ≥ 4 and parity ≥ 1 irrespective of whether or not the women were hypertensive.

Use of labour induction and risk of cesarean delivery: a systematic review and meta-analysis

BACKGROUND

Induction of labour is common, and cesarean delivery is regarded as its major complication. We conducted a systematic review and meta-analysis to investigate whether the risk of cesarean delivery is higher or lower following labour induction compared with expectant management.

METHODS

We searched 6 electronic databases for relevant articles published through April 2012 to identify randomized controlled trials (RCTs) in which labour induction was compared with placebo or expectant management among women with a viable singleton pregnancy. We assessed risk of bias and obtained data on rates of cesarean delivery. We used regression analysis techniques to explore the effect of patient characteristics, induction methods and study quality on risk of cesarean delivery.

RESULTS

We identified 157 eligible RCTs (n = 31,085). Overall, the risk of cesarean delivery was 12% lower with labour induction than with expectant management (pooled relative risk [RR] 0.88, 95% confidence interval [CI] 0.84-0.93; I(2) = 0%). The effect was significant in term and post-term gestations but not in preterm gestations. Meta-regression analysis showed that initial cervical score, indication for induction and method of induction did not alter the main result. There was a reduced risk of fetal death (RR 0.50, 95% CI 0.25-0.99; I(2) = 0%) and admission to a neonatal intensive care unit (RR 0.86, 95% CI 0.79-0.94), and no impact on maternal death (RR 1.00, 95% CI 0.10-9.57; I(2) = 0%) with labour induction.

INTERPRETATION

The risk of cesarean delivery was lower among women whose labour was induced than among those managed expectantly in term and post-term gestations. There were benefits for the fetus and no increased risk of maternal death.

Induction of labour for improving birth outcomes for women at or beyond term

BACKGROUND

As a pregnancy continues beyond term the risks of babies dying inside the womb or in the immediate newborn period increase. Whether a policy of labour induction at a predetermined gestational age can reduce this increased risk is the subject of this review.

OBJECTIVES

To evaluate the benefits and harms of a policy of labour induction at term or post-term compared with awaiting spontaneous labour or later induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2012).

SELECTION CRITERIA

Randomised controlled trials conducted in women at or beyond term. The eligible trials were those comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour. Cluster-randomised trials and cross-over trials are not included. Quasi-random allocation schemes such as alternation, case record numbers or open random-number lists were not eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion. Two review authors independently assessed trial quality and extracted data. Data were checked for accuracy. Outcomes are analysed in two main categories: gestational age and cervix status.

MAIN RESULTS

We included 22 trials reporting on 9383 women. The trials were generally at moderate risk of bias.Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths: risk ratio (RR) 0.31, 95% confidence interval (CI) 0.12 to 0.88; 17 trials, 7407 women. There was one perinatal death in the labour induction policy group compared with 13 perinatal deaths in the expectant management group. The number needed to treat to benefit (NNTB) with induction of labour in order to prevent one perinatal death was 410 (95% CI 322 to 1492).For the primary outcome of perinatal death and most other outcomes, no differences between timing of induction subgroups were seen; the majority of trials adopted a policy of induction at 41 completed weeks (287 days) or more.Fewer babies in the labour induction group had meconium aspiration syndrome (RR 0.50, 95% CI 0.34 to 0.73; eight trials, 2371 infants) compared with a policy of expectant management. There was no statistically significant difference between the rates of neonatal intensive care unit (NICU) admission for induction compared with expectant management (RR 0.90, 95% CI 0.78 to 1.04; 10 trials, 6161 infants). For women in the policy of induction arms of trials, there were significantly fewer caesarean sections compared with expectant management in 21 trials of 8749 women (RR 0.89, 95% CI 0.81 to 0.97).

AUTHORS' CONCLUSIONS

A policy of labour induction compared with expectant management is associated with fewer perinatal deaths and fewer caesarean sections. Some infant morbidities such as meconium aspiration syndrome were also reduced with a policy of post-term labour induction although no significant differences in the rate of NICU admission were seen.However, the absolute risk of perinatal death is small. Women should be appropriately counselled in order to make an informed choice between scheduled induction for a post-term pregnancy or monitoring without induction (or delayed induction).

Randomized clinical trial evaluating the frequency of membrane sweeping with an unfavorable cervix at 39 weeks

BACKGROUND

Despite the widely accepted use of membrane sweeping to prevent postmaturity pregnancies, the optimal frequency for this procedure has not been established.

AIM

To determine if the frequency of membrane sweeping in women with an unfavorable cervix at term results in fewer labor inductions.

METHODS

This was a randomized trial of women with an unfavorable cervix (Bishop's score of ≤4) at 39 weeks randomized into three groups: control, once-weekly membrane sweeping, and twice-weekly membrane sweeping.

RESULTS

Between January 2005 and June 2008, 350 women were randomized into the study (groups: control [n = 116], once weekly [n = 117], and twice weekly [n = 117]). Randomization of Bishop's score was different between groups (P = 0.019), with 67%, 71%, and 83% of control, once-, and twice-weekly groups, respectively, having scores of 3-4. There was no difference in the unadjusted rate of labor induction between the groups (35% versus 27% versus 23%, P = 0.149), and after the adjustment for the randomization of Bishop's score (adjusted odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.41-1.29 and OR = 0.65, 95% CI 0.36-1.18 for once- and twice-weekly groups, respectively). A Bishop's score of 3-4 at randomization was the only statistically significant factor that decreased the likelihood of induction at 41 weeks (OR = 0.42, 95% CI 0.25-0.69).

CONCLUSION

Frequency of membrane sweeping does not influence the likelihood of remaining undelivered at 41 weeks of pregnancy. The Bishop's score at around 39 weeks is the important factor as a predictor of the duration of pregnancy, and further studies would be required to determine whether membrane sweeping influences pregnancy duration.

Different methods for the induction of labour in outpatient settings

BACKGROUND

Induction of labour is carried out for a variety of indications and using a range of pharmacological, mechanical and other methods. For women at low risk, some methods of induction of labour may be suitable for use in outpatient settings.

OBJECTIVES

To examine pharmacological and mechanical interventions to induce labour in outpatient settings in terms of feasibility, effectiveness, maternal satisfaction, healthcare costs and, where information is available, safety. The review complements existing reviews on labour induction examining effectiveness and safety.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (December 2009) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining outpatient cervical ripening or induction of labour with pharmacological agents or mechanical methods.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed eligible papers for risk of bias. We checked all data after entry into review manager software.

MAIN RESULTS

We included 28 studies with 2616 women examining different methods of induction of labour where women received treatment at home or were sent home after initial treatment and monitoring in hospital.Studies examined vaginal and intracervical PGE(2), vaginal and oral misoprostol, isosorbide mononitrate, mifepristone, oestrogens, and acupuncture. Overall, the results demonstrate that outpatient induction of labour is feasible and that important adverse events are rare. There was no strong evidence that agents used to induce labour in outpatient settings had an impact (positive or negative) on maternal or neonatal health. There was some evidence that, compared to placebo or no treatment, induction agents reduced the need for further interventions to induce labour, and shortened the interval from intervention to birth. We were unable to pool results on outcomes relating to progress in labour as studies tended to measure a very broad range of outcomes.There was no evidence that induction agents increased interventions in labour such as operative deliveries. Only two studies provided information on women's views about the induction process, and overall there was very little information on the costs to health service providers of different methods of labour induction in outpatient settings.

AUTHORS' CONCLUSIONS

Induction of labour in outpatient settings appears feasible. We do not have sufficient evidence to know which induction methods are preferred by women, or the interventions that are most effective and safe to use in outpatient settings.

Induction of labour for improving birth outcomes for women at or beyond term

BACKGROUND

As a pregnancy continues beyond term the risks of babies dying inside the womb or in the immediate newborn period increase. Whether a policy of labour induction at a predetermined gestational age can reduce this increased risk is the subject of this review.

OBJECTIVES

To evaluate the benefits and harms of a policy of labour induction at term or post-term compared to awaiting spontaneous labour or later induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2006).

SELECTION CRITERIA

Randomized controlled trials conducted in women at or beyond term. The eligible trials were those comparing a policy of labour induction to a policy of awaiting spontaneous onset of labour. Trials comparing cervical ripening methods, membrane stripping/sweeping or nipple stimulation without any commitment to delivery within a certain time were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated potentially eligible trials and extracted data. Outcomes are analysed in two main categories: gestational age and cervix status.

MAIN RESULTS

We included 19 trials reporting on 7984 women. A policy of labour induction at 41 completed weeks or beyond was associated with fewer (all-cause) perinatal deaths (1/2986 versus 9/2953; relative risk (RR) 0.30; 95% confidence interval (CI) 0.09 to 0.99). The risk difference is 0.00 (95% CI 0.01 to 0.00). If deaths due to congenital abnormality are excluded, no deaths remain in the labour induction group and seven deaths remain in the no-induction group. There was no evidence of a statistically significant difference in the risk of caesarean section (RR 0.92; 95% CI 0.76 to 1.12; RR 0.97; 95% CI 0.72 to 1.31) for women induced at 41 and 42 completed weeks respectively. Women induced at 37 to 40 completed weeks were more likely to have a caesarean section with expectant management than those in the labour induction group (RR 0.58; 95% CI 0.34 to 0.99). There were fewer babies with meconium aspiration syndrome (41+: RR 0.29; 95% CI 0.12 to 0.68, four trials, 1325 women; 42+: RR 0.66; 95% CI 0.24 to 1.81, two trials, 388 women).

AUTHORS' CONCLUSIONS

A policy of labour induction after 41 completed weeks or later compared to awaiting spontaneous labour either indefinitely or at least one week is associated with fewer perinatal deaths. However, the absolute risk is extremely small. Women should be appropriately counselled on both the relative and absolute risks.

Prior Cesarean: A Contraindication to Labor Induction?

In 2004, cesarean rates were the highest ever in the United States. Simultaneously, the vaginal birth after cesarean (VBAC) rate fell, largely a result of reports of uterine rupture associated with VBAC attempts. This chapter reviews the efficacy and safety of VBAC associated with labor induction. Mechanical and pharmacologic methods of labor induction (notably misoprostol) are associated with increased maternal and perinatal morbidity compared with spontaneous VBAC attempts. However, the absolute risks remain low. Labor induction is not contraindicated in women with a prior cesarean but sound judgment, clinical precautions and specific consent are required.

Prise en charge obstétricale des grossesses prolongées au-delà de 41 semaines d’aménorrhée avec un score de Bishop défavorable

OBJECTIVE

Our purpose was to determine the optimal management of pregnancies beyond 41 week's gestation with a cervix unfavorable for induction.

MATERIAL AND METHOD

All uncomplicated pregnancies that reached 41 weeks'gestation with a Bishop score of< or =4, were randomly assigned to one of two groups

RESULTS

The duration of labor was shorter in the group "prépidil" compared with the control group (P=0.002). Identification of an unfavorable cervix at 41 weeks was unlikely to change by 42 weeks and cervical ripening was required in 40% cases. There was no significant difference in caesarean section rates. Rates of admission into the neonatal unit and fetal outcomes were similar in the two groups.

CONCLUSION

Cervical ripening with prostaglandin gel at 41 week's gestation for uncomplicated singleton pregnancies is safe and should be advocated.

Outpatient misoprostol cervical ripening without subsequent induction of labor to prevent post-term pregnancy

BACKGROUND

Interventions that may help shorten the duration of pregnancy in an African setting where facilities for fetal monitoring in post-term pregnancy are limited, and induction is not without its hazards, are needed.

AIM

To determine whether outpatient administration of intravaginal misoprostol safely decreases the interval to delivery in postdate pregnancies.

DESIGN

Open randomized controlled trial.

SETTING

Zonal district hospitals, Kwale, Southern Nigeria (August 2000 to October 2001).

METHODS

Seventy-seven women were randomized at 40 weeks gestation to receive either 25 microg misoprostol intravaginally (38) or gentle cervical assessment only (39) on an outpatient basis. Subjects were then allowed to go into spontaneous labor unless an indication for induction developed.

MAIN OUTCOME MEASURES

Interval to delivery, duration of labor, and incidence of side-effects.

RESULTS

Misoprostol was associated with significant decrease in mean time to delivery (4.5 +/- 4.1 versus 7.4 +/- 5.2 days; P = 0.008), earlier gestational age at delivery (40.6 +/- 0.6 versus 41.4 +/- 0.05 weeks; P < 0.001) and shorter duration of active labor (6.1 +/- 4.0 versus 8.2 +/- 5.3 h; P = 0.028), without any significant increase in fetal distress, low Apgar score at delivery or other side-effects.

CONCLUSION

Outpatient administration of low-dose misoprostol can safely shorten the length of gestation in postdate pregnancies.

Membrane sweeping for induction of labour

BACKGROUND

Sweeping of the membranes, also named stripping of the membranes, is a relatively simple technique usually performed without admission to hospital. During vaginal examination, the clinician's finger is introduced into the cervical os. Then, the inferior pole of the membranes is detached from the lower uterine segment by a circular movement of the examining finger. This intervention has the potential to initiate labour by increasing local production of prostaglandins and, thus, reduce pregnancy duration or pre-empt formal induction of labour with either oxytocin, prostaglandins or amniotomy. 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 membrane sweeping for third trimester induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (6 July 2004) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing membrane sweeping 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.

DATA COLLECTION AND ANALYSIS

A strategy was 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.

MAIN RESULTS

Twenty-two trials (2797 women) were included, 20 comparing sweeping of membranes with no treatment, three comparing sweeping with prostaglandins and one comparing sweeping with oxytocin (two studies reported more than one comparison). Risk of caesarean section was similar between groups (relative risk (RR) 0.90, 95% confidence interval (CI) 0.70 to 1.15). Sweeping of the membranes, performed as a general policy in women at term, was associated with reduced duration of pregnancy and reduced frequency of pregnancy continuing beyond 41 weeks (RR 0.59, 95% CI 0.46 to 0.74) and 42 weeks (RR 0.28, 95% CI 0.15 to 0.50). To avoid one formal induction of labour, sweeping of membranes must be performed in eight women (NNT = 8). There was no evidence of a difference in the risk of maternal or neonatal infection. Discomfort during vaginal examination and other adverse effects (bleeding, irregular contractions) were more frequently reported by women allocated to sweeping. Studies comparing sweeping with prostaglandin administration are of limited sample size and do not provide evidence of benefit.

AUTHORS' CONCLUSIONS

Routine use of sweeping of membranes from 38 weeks of pregnancy onwards does not seem to produce clinically important benefits. When used as a means for induction of labour, the reduction in the use of more formal methods of induction needs to be balanced against women's discomfort and other adverse effects.

Misoprostol Outpatient Cervical Ripening Without Subsequent Induction of Labor: A Randomized Trial

OBJECTIVE

To estimate the effect of outpatient administration of a single dose of vaginal misoprostol at term on the interval to delivery in women with unfavorable cervices.

METHODS

Randomized, double blind, placebo-controlled trial comparing a single 25-microg outpatient intravaginal dose of misoprostol to placebo in pregnant women with Bishop scores less than 9 at 40 weeks or greater. After placement of the study medication, subjects were permitted to go into spontaneous labor unless an indication for induction developed. Analysis was by intent to treat. The interval to delivery, defined as the time from medication placement to delivery, was compared by Student t test and by survival analysis with the log-rank test.

RESULTS

Thirty-three women were randomly assigned to receive misoprostol, and 35 were assigned to receive placebo. The mean interval to delivery was significantly less in the misoprostol group, 4.2 +/- 4.1 compared with 6.1 +/- 3.6 days, P =.04. The interval to delivery for only the nulliparous patients was significantly less in the misoprostol group, 4.2 +/- 4.0 compared with 7.2 +/- 3.7 days, P =.02. The survival curves for the interval to delivery were significantly different (P =.04 by log-rank test) with 4.1 days median interval to delivery for misoprostol compared with 9.2 days for placebo. There were no adverse outcomes in either group.

CONCLUSION

A single 25-microg outpatient intravaginal dose of misoprostol is effective in decreasing the interval to delivery in women with unfavorable cervices at term.

Elective induction: an analysis of economic and health consequences

OBJECTIVE

Our purpose was to assess economic and health consequences of elective induction at term.

STUDY DESIGN

A decision-tree model incorporating a Markov analysis was used to compare the decision either to electively induce labor at term or expectantly manage the pregnancy until 42 weeks' gestation. Main outcome measures, stratified by parity, cervical ripeness, and gestational age at induction, were number of cesarean deliveries and costs to the health care system.

RESULTS

By use of baseline estimates, induction at any gestational age, regardless of parity and cervical ripeness, required expenditures from the medical system. Although never cost saving, inductions were less expensive at later gestational ages, for multiparous patients, and for those women with a favorable cervix. Sensitivity analysis demonstrated a robust model.

CONCLUSIONS

Elective induction of labor at term is not cost saving and results in a large excess of cesarean deliveries. Costs are significantly altered by the timing of the induction, parity, and cervical ripeness.

Does sweeping of membranes beyond 40 weeks reduce the need for formal induction of labour?

OBJECTIVE

To assess the efficacy of sweeping of membranes beyond 40 weeks of gestation in reducing the incidence of induction of labour, when induction was planned at 42 weeks.

DESIGN

Prospective randomised controlled trial.

SETTING

A regional obstetric unit in Hong Kong.

POPULATION AND METHODS

A total of 120 women with certain gestational age, determined by early pregnancy ultrasound scan, were recruited from 1st July, 1998 to 31st December, 1999. Sixty women were randomly allocated to sweeping of membranes and the other 60 women acted as control. The satisfaction for women allocated to sweeping of membranes was assessed by a questionnaire after the procedure. The two groups were assessed on intention-to-treat basis.

MAIN OUTCOME MEASURES

The incidence of formal induction of labour was compared between the two groups. Possible complications of sweeping of membranes such as rupture of membranes, intrapartum infection, postpartum infection, and neonatal infection were also assessed. Maternal and perinatal outcomes were also assessed.

RESULTS

The recruitment to delivery interval was significantly shorter among women who had sweeping of membranes (3.2 versus 4.2 days, P < 0.05). The incidence of induction of labour was comparable (35.5% versus 38%, RR 0.91, 95% CI 0.57 - 1.46). The incidences of caesarean section and assisted vaginal delivery were comparable. The incidences of premature rupture of membranes, intrapartum, and postpartum infection were comparable. The perinatal outcomes were also comparable between the two groups. Up to 70% of women found that this procedure was associated with significant discomfort. One third of these women complained of significant pain.

CONCLUSIONS

Sweeping of membranes beyond 40 weeks does not reduce the need for formal induction of labour at 42 weeks. Although it is safe, the majority of women felt uncomfortable during the procedure.

Outpatient cervical ripening with prostaglandin E2 and estradiol

OBJECTIVE

To determine whether weekly outpatient administration of prostaglandin gel or estrogen cream initiated labor in women with an unfavorable cervix.

METHODS

All uncomplicated pregnancies at term gestation who were candidates for a vaginal delivery with a Bishop score of < or = 6 were randomly assigned to receive on a weekly basis: prostaglandin E2 gel (n = 41); estrogen cream (n = 44); or inert lubricant jelly (n = 43).

RESULTS

In the three groups no differences were observed among 128 subjects in the weekly Bishop scores, cervical dilatation or gestational age upon admission to the labor and delivery suite, the percentage of patients presenting with spontaneous labor or ruptured membranes, the number of post-date inductions or neonatal outcome.

CONCLUSIONS

Weekly out-patient cervical ripening using either prostaglandin gel or estrogen in women with an unfavorable cervix at 37 weeks' gestation was no more effective than a placebo in Bishop score improvement or in preventing post-date inductions.

Sweeping of the membranes to prevent post-term pregnancy and to induce labour: a systematic review

OBJECTIVE

To evaluate the effectiveness of sweeping of the membranes to prevent post-term pregnancy and to induce labour.

DESIGN

A systematic review of randomised controlled trials.

METHODS

Potentially eligible trials were identified in Medline and in the Cochrane Controlled Trials Register. Inclusion of studies and data extraction were performed by two reviewers working independently. Summary estimates of the effect of the intervention were computed as relative risks, risk differences and weighted mean differences.

MAIN OUTCOME MEASURES

Use of formal methods of labour induction, delay before spontaneous onset of labour, prevention of post-term pregnancy, side effects, maternal and perinatal morbidity.

RESULTS

Sixteen reports were identified. Thirteen were included in the review, with a total of 1992 women. Sweeping of the membranes, when performed at term, reduced the duration of pregnancy and the proportion of women continuing pregnancy beyond 41 and 42 weeks. When sweeping of the membranes was performed, a reduction in the use of formal methods for labour induction was observed (RR = 0.48; 95% CI 0.28-0.85). There was no difference between groups in the mode of delivery or in the risk of infection. Discomfort during vaginal examination and other side effects (e.g. bleeding, irregular contractions) were more frequently reported by women allocated to sweeping.

CONCLUSIONS

While sweeping of the membranes reduces the interval to spontaneous onset of labour, there is no evidence of a reduction in maternal or neonatal morbidity. When used as a means of induction of labour, the reduction in the use of formal methods must be balanced against women's discomfort and other side effects attributable to the procedure.

Risk factors for secondary arrest of labor among women >41 weeks' gestation with an unfavorable cervix undergoing membrane sweeping for cervical ripening

OBJECTIVE

To identify the risk factor(s) for secondary arrest of labor among women with an unfavorable cervix at > 41 weeks' gestation.

METHODS

Prospectively all gravid women with a Bishop score of < or = 4 and no contraindication to a vaginal delivery were candidates for this study. Univariate analysis followed by logistic regression modeling were used to identify variables with a significant association.

RESULTS

Over a 9-month period, 115 women entered into the study. In univariate analysis, variables with a significant association with cesarean delivery: (1) non-Caucasian race (P = 0.007), Bishop score < 7 at hospitalization; P = 0.001, and reason for admission (P = 0.017). Logistic regression analysis yielded OR 4.7 (1.6, 15) non-Caucasian race and 9.5 (3.2, 30.8) Bishop < 7 on admission.

CONCLUSION

Pregnancies > 41 weeks with an unfavorable cervix, non-Caucasian race and a failure to achieve a Bishop score of > or = 7 prior to hospitalization were significant risk factors for abdominal delivery.

Can we decrease postdatism in women with an unfavorable cervix and a negative fetal fibronectin test result at term by serial membrane sweeping?

OBJECTIVE

Our purpose was to determine whether the risk for postdatism can be reduced by serial membrane sweeping in women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result.

STUDY DESIGN

Women with uncomplicated pregnancies, who were candidates for a vaginal delivery with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result were asked to participate in this investigation. Patients were chosen at random and assigned to a group for membrane sweeping every 3 days or to a control group who received gentle examinations every 3 days.

RESULTS

Sixty-five women were selected at random for serial membrane sweeping (n = 33) or for the control group (n = 32). Although gestational age and Bishop score at study entry were similar, the gestational age on admission for delivery was earlier in the membrane sweeping group (39.9 +/- 0.3) versus the control group (41.5 +/- 0.6, P < .0001). The Bishop score on admission to labor and delivery was greater (8.8 +/- 2.1) in the membrane sweeping group than in the control group (6.2 +/- 2.7, P < .0001). The number of women admitted for labor inductions at 42 weeks' gestation was 18 of 32 (56%) in the control group versus none (0 of 24) in the membrane-sweeping group (P < .0001).

CONCLUSIONS

Women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result are at risk for not being delivered by 41 completed weeks and thus may require postdates induction or antenatal testing. Serial membrane sweeping significantly reduces the risk of postdatism and induction of labor.