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The Cochrane Database of Systematic... Mar 2023Mechanical methods were the first methods developed to ripen the cervix and induce labour. During recent decades they have been substituted by pharmacological methods.... (Review)
Review
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.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Cesarean Section; Dinoprostone; Labor, Induced; Misoprostol; Oxytocin; Perinatal Death
PubMed: 36996264
DOI: 10.1002/14651858.CD001233.pub4 -
PloS One 2021As uterine rupture may affect as many as 11/1000 women with 1 prior cesarean birth and 5/10.000 women with unscarred uterus undergoing labor induction, we intended to... (Meta-Analysis)
Meta-Analysis
Prevalence of uterine rupture among women with one prior low transverse cesarean and women with unscarred uterus undergoing labor induction with PGE2: A systematic review and meta-analysis.
BACKGROUND
As uterine rupture may affect as many as 11/1000 women with 1 prior cesarean birth and 5/10.000 women with unscarred uterus undergoing labor induction, we intended to estimate the prevalence of such rare outcome when PGE2 is used for cervical ripening and labor induction.
METHODS
We searched MEDLINE, ClinicalTrials.gov and the Cochrane library up to September 1st 2020. Retrospective and prospective cohort studies, as well as randomized controlled trials (RCTs) on singleton viable pregnancies receiving PGE2 for cervical ripening and labor induction were reviewed. Prevalence of uterine rupture was meta-analyzed with Freeman-Tukey double arcsine transformation among women with 1 prior low transverse cesarean section and women with unscarred uterus.
RESULTS
We reviewed 956 full text articles to include 69 studies. The pooled prevalence rate of uterine rupture is estimated to range between 2 and 9 out of 1000 women with 1 prior low transverse cesarean (5/1000; 95%CI 2-9/1000, 122/9000). The prevalence of uterine rupture among women with unscarred uterus is extremely low, reaching at most 0.7/100.000 (<1/100.000.000; 95%CI <1/100.000.000-0.7/100.000, 8/17.684).
CONCLUSIONS
Uterine rupture is a rare event during cervical ripening and labor induction with PGE2.
Topics: Adult; Cesarean Section; Dinoprostone; Female; Humans; Labor, Induced; Pregnancy; Prevalence; Publication Bias; Uterine Rupture; Uterus
PubMed: 34228760
DOI: 10.1371/journal.pone.0253957 -
The Cochrane Database of Systematic... Jun 2021Misoprostol given orally is a commonly used labour induction method. Our Cochrane Review is restricted to studies with low-dose misoprostol (initially ≤ 50 µg), as... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Misoprostol given orally is a commonly used labour induction method. Our Cochrane Review is restricted to studies with low-dose misoprostol (initially ≤ 50 µg), as higher doses pose unacceptably high risks of uterine hyperstimulation.
OBJECTIVES
To assess the efficacy and safety of low-dose oral misoprostol for labour induction in women with a viable fetus in the third trimester of pregnancy.
SEARCH METHODS
We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (14 February 2021) and reference lists of retrieved studies.
SELECTION CRITERIA
Randomised trials comparing low-dose oral misoprostol (initial dose ≤ 50 µg) versus placebo, vaginal dinoprostone, vaginal misoprostol, oxytocin, or mechanical methods; or comparing oral misoprostol protocols (one- to two-hourly versus four- to six-hourly; 20 µg to 25 µg versus 50 µg; or 20 µg hourly titrated versus 25 µg two-hourly static).
DATA COLLECTION AND ANALYSIS
Using Covidence, two review authors independently screened reports, extracted trial data, and performed quality assessments. Our primary outcomes were vaginal birth within 24 hours, caesarean section, and hyperstimulation with foetal heart changes.
MAIN RESULTS
We included 61 trials involving 20,026 women. GRADE assessments ranged from moderate- to very low-certainty evidence, with downgrading decisions based on imprecision, inconsistency, and study limitations. Oral misoprostol versus placebo/no treatment (four trials; 594 women) Oral misoprostol may make little to no difference in the rate of caesarean section (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.59 to 1.11; 4 trials; 594 women; moderate-certainty evidence), while its effect on uterine hyperstimulation with foetal heart rate changes is uncertain (RR 5.15, 95% CI 0.25 to 105.31; 3 trials; 495 women; very low-certainty evidence). Vaginal births within 24 hours was not reported. In all trials, oxytocin could be commenced after 12 to 24 hours and all women had pre-labour ruptured membranes. Oral misoprostol versus vaginal dinoprostone (13 trials; 9676 women) Oral misoprostol probably results in fewer caesarean sections (RR 0.84, 95% CI 0.78 to 0.90; 13 trials, 9676 women; moderate-certainty evidence). Subgroup analysis indicated that 10 µg to 25 µg (RR 0.80, 95% CI 0.74 to 0.87; 9 trials; 8652 women) may differ from 50 µg (RR 1.10, 95% CI 0.91 to 1.34; 4 trials; 1024 women) for caesarean section. Oral misoprostol may decrease vaginal births within 24 hours (RR 0.93, 95% CI 0.87 to 1.00; 10 trials; 8983 women; low-certainty evidence) and hyperstimulation with foetal heart rate changes (RR 0.49, 95% CI 0.40 to 0.59; 11 trials; 9084 women; low-certainty evidence). Oral misoprostol versus vaginal misoprostol (33 trials; 6110 women) Oral use may result in fewer vaginal births within 24 hours (average RR 0.81, 95% CI 0.68 to 0.95; 16 trials, 3451 women; low-certainty evidence), and less hyperstimulation with foetal heart rate changes (RR 0.69, 95% CI 0.53 to 0.92, 25 trials, 4857 women, low-certainty evidence), with subgroup analysis suggesting that 10 µg to 25 µg orally (RR 0.28, 95% CI 0.14 to 0.57; 6 trials, 957 women) may be superior to 50 µg orally (RR 0.82, 95% CI 0.61 to 1.11; 19 trials; 3900 women). Oral misoprostol probably does not increase caesarean sections overall (average RR 1.00, 95% CI 0.86 to 1.16; 32 trials; 5914 women; low-certainty evidence) but likely results in fewer caesareans for foetal distress (RR 0.74, 95% CI 0.55 to 0.99; 24 trials, 4775 women). Oral misoprostol versus intravenous oxytocin (6 trials; 737 women, 200 with ruptured membranes) Misoprostol may make little or no difference to vaginal births within 24 hours (RR 1.12, 95% CI 0.95 to 1.33; 3 trials; 466 women; low-certainty evidence), but probably results in fewer caesarean sections (RR 0.67, 95% CI 0.50 to 0.90; 6 trials; 737 women; moderate-certainty evidence). The effect on hyperstimulation with foetal heart rate changes is uncertain (RR 0.66, 95% CI 0.19 to 2.26; 3 trials, 331 women; very low-certainty evidence). Oral misoprostol versus mechanical methods (6 trials; 2993 women) Six trials compared oral misoprostol to transcervical Foley catheter. Misoprostol may increase vaginal birth within 24 hours (RR 1.32, 95% CI 0.98 to 1.79; 4 trials; 1044 women; low-certainty evidence), and probably reduces the risk of caesarean section (RR 0.84, 95% CI 0.75 to 0.95; 6 trials; 2993 women; moderate-certainty evidence). There may be little or no difference in hyperstimulation with foetal heart rate changes (RR 1.31, 95% CI 0.78 to 2.21; 4 trials; 2828 women; low-certainty evidence). Oral misoprostol one- to two-hourly versus four- to six-hourly (1 trial; 64 women) The evidence on hourly titration was very uncertain due to the low numbers reported. Oral misoprostol 20 µg hourly titrated versus 25 µg two-hourly static (2 trials; 296 women) The difference in regimen may have little or no effect on the rate of vaginal births in 24 hours (RR 0.97, 95% CI 0.80 to 1.16; low-certainty evidence). The evidence is of very low certainty for all other reported outcomes.
AUTHORS' CONCLUSIONS
Low-dose oral misoprostol is probably associated with fewer caesarean sections (and therefore more vaginal births) than vaginal dinoprostone, and lower rates of hyperstimulation with foetal heart rate changes. However, time to birth may be increased, as seen by a reduced number of vaginal births within 24 hours. Compared to transcervical Foley catheter, low-dose oral misoprostol is associated with fewer caesarean sections, but equivalent rates of hyperstimulation. Low-dose misoprostol given orally rather than vaginally is probably associated with similar rates of vaginal birth, although rates may be lower within the first 24 hours. However, there is likely less hyperstimulation with foetal heart changes, and fewer caesarean sections performed due to foetal distress. The best available evidence suggests that low-dose oral misoprostol probably has many benefits over other methods for labour induction. This review supports the use of low-dose oral misoprostol for induction of labour, and demonstrates the lower risks of hyperstimulation than when misoprostol is given vaginally. More trials are needed to establish the optimum oral misoprostol regimen, but these findings suggest that a starting dose of 25 µg may offer a good balance of efficacy and safety.
Topics: Administration, Intravaginal; Administration, Oral; Apgar Score; Cesarean Section; Dinoprostone; Drug Administration Schedule; Female; Heart Rate, Fetal; Humans; Intensive Care, Neonatal; Labor, Induced; Misoprostol; Oxytocics; Oxytocin; Parturition; Placebos; Pregnancy; Randomized Controlled Trials as Topic; Time Factors; Uterus
PubMed: 34155622
DOI: 10.1002/14651858.CD014484 -
Obstetrics and Gynecology Jun 2021To assess the comparative effectiveness and potential harms of cervical ripening in the outpatient compared with the inpatient setting, or different methods of ripening... (Meta-Analysis)
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.
Topics: Ambulatory Care; Catheters; Cervical Ripening; Cesarean Section; Dilatation; Dinoprostone; Female; Hospitalization; Humans; Labor, Induced; Obstetric Labor Complications; Oxytocics; Pregnancy
PubMed: 33752219
DOI: 10.1097/AOG.0000000000004382 -
The Cochrane Database of Systematic... Aug 2020The setting in which induction of labour takes place (home or inpatient) is likely to have implications for safety, women's experiences and costs. Home induction may be... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
The setting in which induction of labour takes place (home or inpatient) is likely to have implications for safety, women's experiences and costs. Home induction may be started at home with the subsequent active phase of labour happening either at home or in a healthcare facility (hospital, birth centre, midwifery-led unit). More commonly, home induction starts in a healthcare facility, then the woman goes home to await the start of labour. Inpatient induction takes place in a healthcare facility where the woman stays while awaiting the start of labour.
OBJECTIVES
To assess the effects on neonatal and maternal outcomes of third trimester home induction of labour compared with inpatient induction using the same method of induction.
SEARCH METHODS
For this update, we searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (31 January 2020)), and reference lists of retrieved studies.
SELECTION CRITERIA
Published and unpublished randomised controlled trials (RCTs) in which home and inpatient settings for induction have been compared. We included conference abstracts but excluded quasi-randomised trials and cross-over studies.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed study reports for inclusion. Two review authors carried out data extraction and assessment of risk of bias independently. GRADE assessments were checked by a third review author.
MAIN RESULTS
We included seven RCTs, six of which provided data on 1610 women and their babies. Studies were undertaken between 1998 and 2015, and all were in high- or upper-middle income countries. Most women were induced for post dates. Three studies reported government funding, one reported no funding and three did not report on their funding source. Most GRADE assessments gave very low-certainty evidence, downgrading mostly for high risk of bias and serious imprecision. 1. Home compared to inpatient induction with vaginal prostaglandin E (PGE) (two RCTs, 1028 women and babies; 1022 providing data). Although women's satisfaction may be slightly better in home settings, the evidence is very uncertain (mean difference (MD) 0.16, 95% confidence interval (CI) -0.02 to 0.34, 1 study, 399 women), very low-certainty evidence. There may be little or no difference between home and inpatient induction for other primary outcomes, with all evidence being very low certainty: - spontaneous vaginal birth (average risk ratio (RR) [aRR] 0.91, 95% CI 0.69 to 1.21, 2 studies, 1022 women, random-effects method); - uterine hyperstimulation (RR 1.19, 95% CI 0.40 to 3.50, 1 study, 821 women); - caesarean birth (RR 1.01, 95% CI 0.81 to 1.28, 2 studies, 1022 women); - neonatal infection (RR 1.29, 95% CI 0.59 to 2.82, 1 study, 821 babies); - admission to neonatal intensive care unit (NICU) (RR 1.20, 95% CI 0.50 to 2.90, 2 studies, 1022 babies). Studies did not report serious neonatal morbidity or mortality. 2. Home compared to inpatient induction with controlled release PGE (one RCT, 299 women and babies providing data). There was no information on whether the questionnaire on women's satisfaction with care used a validated instrument, but the findings presented showed no overall difference in scores. We found little or no difference between the groups for other primary outcomes, all also being very low-certainty evidence: - spontaneous vaginal birth (RR 0.94, 95% CI 0.77 to 1.14, 1 study, 299 women); - uterine hyperstimulation (RR 1.01, 95% CI 0.51 to 1.98, 1 study, 299 women); - caesarean births (RR 0.95, 95% CI 0.64 to 1.42, 1 study, 299 women); - admission to NICU (RR 1.38, 0.57 to 3.34, 1 study, 299 babies). The study did not report on neonatal infection nor serious neonatal morbidity or mortality. 3. Home compared to inpatient induction with balloon or Foley catheter (four RCTs; three studies, 289 women and babies providing data). It was again unclear whether questionnaires reporting women's experiences/satisfaction with care were validated instruments, with one study (48 women, 69% response rate) finding women were similarly satisfied. Home inductions may reduce the number of caesarean births, but the data are also compatible with a slight increase and are of very low-certainty (RR 0.64, 95% CI 0.41 to 1.01, 2 studies, 159 women). There was little or no difference between the groups for other primary outcomes with all being very low-certainty evidence: - spontaneous vaginal birth (RR 1.04, 95% CI 0.54 to 1.98, 1 study, 48 women): - uterine hyperstimulation (RR 0.45, 95% CI 0.03 to 6.79, 1 study, 48 women); - admission to NICU (RR 0.37, 95% CI 0.07 to 1.86, 2 studies, 159 babies). There were no serious neonatal infections nor serious neonatal morbidity or mortality in the one study (involving 48 babies) assessing these outcomes.
AUTHORS' CONCLUSIONS
Data on the effectiveness, safety and women's experiences of home versus inpatient induction of labour are limited and of very low-certainty. Given that serious adverse events are likely to be extremely rare, the safety data are more likely to come from very large observational cohort studies rather than relatively small RCTs.
Topics: Ambulatory Care; Catheterization; Cervical Ripening; Cesarean Section; Delayed-Action Preparations; Dinoprostone; Female; Hospitalization; Humans; Infant, Newborn; Labor, Induced; Length of Stay; Oxytocics; Patient Safety; Patient Satisfaction; Pregnancy; Pregnancy Outcome; Randomized Controlled Trials as Topic
PubMed: 32852803
DOI: 10.1002/14651858.CD007372.pub4