Effect of extra-amniotic Foley's catheter and vaginal misoprostol versus vaginal misoprostol alone on cervical ripening and induction of labor in Kenya, a randomized controlled trial

Mechanical methods for induction of labour

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Intracervical Foley catheter plus intravaginal misoprostol compared to intravaginal misoprostol-only for cervical ripening: A systematic review and meta-analysis

To compare the combination of intracervical Foley catheter and intravaginal misoprostol administration versus intravaginal misoprostol administration-only for cervical ripening. The Medline, EMBASE, ClinicalTrials.gov, PROSPERO, Scopus, and Cochrane Collaboration databases were searched systematically. Randomized controlled trials that included patients with a singleton viable fetus who underwent induction of labor that required cervical ripening with an unfavorable cervix (Bishop ≤ 6) were eligible for inclusion. Primary outcomes was time to delivery and rate of cesarean delivery. Thirteen trials with 2978 subjects met the inclusion criteria. There was no difference in the incidence of cesarean delivery between the two groups (RR, 0.90; 95 % CI, 0.72-1.14; I² = 69 %). The combination group resulted in comparable time to delivery (MD -2.50 h; 95 % CI 0.38, -5.38; I² = 97 %), shorter time to vaginal delivery (MD -3.49 h; 95 % CI -4.89, -2.09; I² = 81 %), lower risk of neonatal intensive care unit (NICU) admission (RR 0.72, 95 % CI 0.58-0.90, I² = 0 %), meconium-stained fluid (RR 0.48, 95 % CI 0.31-0.73, I² = 28 %), and tachysystole with fetal heart trace changes (RR 0.49, 95 % CI 0.27-0.86, I² = 43 %), compared with intravaginal misoprostol-only group. There was no statistical difference in rates of terbutaline use, endometritis or chorioamnionitis between the two groups. The combination of intravaginal misoprostol with intracervical Foley catheter for cervical ripening is not associated with shorter time to delivery. However, the combination group shows significant difference in shorter time to vaginal delivery, NICU admission, meconium-stained fluid, and tachysystole with fetal heart trace changes.

Foley catheter plus misoprostol versus misoprostol alone for labor induction

OBJECTIVE

This study aimed to analyze the effects of Foley catheter combined with misoprostol in the labor induction process.

METHODS

This is a nonblinded, block randomized, controlled trial that compared the association between transcervical Foley catheter/vaginal misoprostol 25 μg combination and vaginal misoprostol 25 μg alone in normal-risk and healthy pregnant women undergoing labor induction in the south of Brazil.

RESULTS

A total of 230 patients with indications for labor induction were evaluated and classified into the "combined" group (Foley catheter plus misoprostol), consisting of 107 patients, and the "misoprostol" group (misoprostol only), consisting of 123 patients. The "combined" group was observed to have a shorter labor induction time (p=0.008). In addition, there was a lower need for misoprostol use for overall cervical ripening (p<0.001) and a lower relative risk of needing a second, third, or fourth misoprostol tablet in the "combined" group (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.71-0.91; RR 0.41; 95%CI 0.31-0.56; and RR 0.29, 95%CI 0.17-0.52, respectively) (p<0.001). No statistically significant difference was found in induction failure rate, cesarean section rate, or perinatal outcomes.

CONCLUSION

A combination of methods leads to shorter labor induction, lower need for misoprostol doses, and lower risk of cesarean section, with no increase in the rate of perinatal complications. REBEC number is RBR-7xcjz3z.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Mechanical methods for induction of labour

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

This review update includes a total of 113 trials (22,373 women) contributing data to 21 comparisons. Risk of bias of trials varied. Overall, the evidence was graded from very-low to moderate quality. All evidence was downgraded for lack of blinding and, for many comparisons, the effect estimates were too imprecise to make a valid judgement.Balloon versus vaginal PGE2: there may be little or no difference in vaginal deliveries not achieved within 24 hours (average risk ratio (RR) 1.01, 95% confidence interval (CI) 0.82 to 1.26; 7 studies; 1685 women; I² = 79%; low-quality evidence) and there probably is little or no difference in caesarean sections (RR 1.00, 95% CI 0.92 to 1.09; 28 studies; 6619 women; moderate-quality evidence) between induction of labour with a balloon catheter and vaginal PGE2. A balloon catheter probably reduces the risk of uterine hyperstimulation with fetal heart rate (FHR) changes (RR 0.35, 95% CI 0.18 to 0.67; 6 studies; 1966 women; moderate-quality evidence), serious neonatal morbidity or perinatal death (RR 0.48, 95% CI 0.25 to 0.93; 8 studies; 2757 women; moderate-quality evidence) and may slightly reduce the risk of aneonatal intensive care unit (NICU) admission (RR 0.82, 95% CI 0.65 to 1.04; 3647 women; 12 studies; low-quality evidence). It is uncertain whether there is a difference in serious maternal morbidity or death (RR 0.20, 95% CI 0.01 to 4.12; 4 studies; 1481 women) or five-minute Apgar score < 7 (RR 0.74, 95% CI 0.49 to 1.14; 4271 women; 14 studies) because the quality of the evidence was found to be very low and low, respectively.Balloon versus low-dose vaginal misoprostol: it is uncertain whether there is a difference in vaginal deliveries not achieved within 24 hours between induction of labour with a balloon catheter and vaginal misoprostol (RR 1.09, 95% CI 0.85 to 1.39; 340 women; 2 studies; low-quality evidence). A balloon catheter probably reduces the risk of uterine hyperstimulation with FHR changes (RR 0.39, 95% CI 0.18 to 0.85; 1322 women; 8 studies; moderate-quality evidence) but may increase the risk of a caesarean section (average RR 1.28, 95% CI 1.02 to 1.60; 1756 women; 12 studies; I² = 45%; low-quality evidence). It is uncertain whether there is a difference in serious neonatal morbidity or perinatal death (RR 0.58, 95% CI 0.12 to 2.66; 381 women; 3 studies), serious maternal morbidity or death (no events; 4 studies, 464 women), both very low-quality evidence, and five-minute Apgar score < 7 (RR 1.00, 95% CI 0.50 to 1.97; 941 women; 7 studies) and NICU admissions (RR 1.00, 95% CI 0.61 to 1.63; 1302 women; 9 studies) both low-quality evidence.Balloon versus low-dose oral misoprostol: a balloon catheter probably increases the risk of a vaginal delivery not achieved within 24 hours (RR 1.28, 95% CI 1.13 to 1.46; 782 women, 2 studies, and probably slightly increases the risk of a caesarean section (RR 1.17, 95% CI 1.04 to 1.32; 3178 women; 7 studies; both moderate-quality evidence) when compared to oral misoprostol. It is uncertain whether there is a difference in uterine hyperstimulation with FHR changes (RR 0.81, 95% CI 0.48 to 1.38; 2033 women; 2 studies), serious neonatal morbidity or perinatal death (RR 1.11, 95% CI 0.60 to 2.06; 2627 women; 3 studies), both low-quality evidence, serious maternal morbidity or death (RR 0.50, 95% CI 0.05 to 5.52; 2627 women; 3 studies), very low-quality evidence, five-minute Apgar scores < 7 (RR 0.71, 95% CI 0.38 to 1.32; 2693 women; 4 studies) and NICU admissions (RR 0.82, 95% CI 0.58 to 1.17; 2873 women; 5 studies) both low-quality evidence.

AUTHORS' CONCLUSIONS

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

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

OBJECTIVE DATA

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

STUDY

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

STUDY APPRAISAL AND SYNTHESIS METHODS

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

RESULTS

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

CONCLUSION

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

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

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