Foley catheter versus vaginal prostaglandin E2 gel for induction of labour at term (PROBAAT trial): an open-label, randomised controlled trial

Outpatient cervical ripening with balloon catheters: A Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

One in four labors are induced. The process of cervical ripening can be lengthy and pre-labor hospitalization is required. Outpatient cervical ripening can be an attractive alternative.

OBJECTIVES

To evaluate the efficacy and safety of outpatient cervical ripening with a balloon catheter compared with inpatient balloon catheter or prostaglandin E2 (PGE2).

SEARCH STRATEGY

The PubMed, MEDLINE, Embase, ClinicalTrials.gov, and Cochrane Library databases were searched from their inception to October 15, 2022.

SELECTION CRITERIA

Randomized controlled trials comparing the outpatient balloon catheter with inpatient balloon catheter or inpatient PGE2 for term cervical ripening.

DATA COLLECTION AND ANALYSIS

Bayesian network meta-analysis was performed. The primary outcome was the cesarean delivery rate. The secondary outcomes included instrumental delivery, the time from intervention-to-birth, oxytocin augmentation, total hospital duration, and maternal/neonatal adverse events.

MAIN RESULTS

Twenty-nine randomized controlled trials with a total of 6004 participants were identified. No difference in the cesarean delivery rate was revealed among the three interventions. Compared with inpatient balloon catheter, outpatient balloon catheter had shorter total hospital duration (mean difference -8.58, 95% confidence interval -17.02 to -1.10). No differences were revealed in the time from intervention-to-birth, instrumental delivery, postpartum hemorrhage, 5-min Apgar score less than 7, umbilical cord arterial pH less than 7.1, and neonatal intensive care unit admission among the three interventions.

CONCLUSIONS

Outpatient balloon catheter in low-risk term pregnancies is an available option that could be considered for cervical ripening. The safety and effectiveness are comparable to inpatient cervical ripening methods.

[Prostaglandins or cervical balloon for the induction of labor for cervical ripening: A literature review]

OBJECTIVE

Induction of labor in France concerns one birth out of four with 70% of induction starting by cervical ripening, either with a pharmacological (prostaglandins) or a mechanical (balloon) method. This review aims to compare these two methods within current knowledge, using the PRISMA methodology.

METHODS

Trials comparing these two methods, published or unpublished up to July 2023, in French or English were searched for in the PubMed, Cochrane Library and ClinicalTrial.govs datasets. Fifty articles including 10,689 women were selected. The outcomes of interest were those from the Core Outcome Set for trails on Induction of Labour (COSIOL) list: mode of delivery, time from induction-to-birth, maternal and neonatal morbidity, and maternal satisfaction.

RESULT

No differences were observed between the two methods for the mode of delivery or neonatal and maternal morbidity. The time from induction-to-birth was longer for mechanical methods. Those were also associated with a greater need for oxytocin, less uterine hyperstimulation and less instrumental deliveries. Maternal satisfaction was assessed in only nine trials using various scales which made the interpretation of maternal satisfaction.

CONCLUSION

The efficacy of these two induction methods is similar for vaginal delivery, but it remains to be seen which one best meets women's satisfaction criteria.

Cervical ripening balloon compared with vaginal dinoprostone for cervical ripening in obese women at term: A prospective cohort study

OBJECTIVE

To evaluate vaginal delivery in obese women who underwent cervical ripening at term using a dinoprostone vaginal insert or a cervical ripening balloon (CRB), and to assess maternal and neonatal morbidity according to the method.

METHODS

A prospective cohort study including obese women with a live singleton fetus in cephalic presentation who required cervical ripening at term (≥37 weeks) for maternal and/or fetal disease using a dinoprostone vaginal insert or a CRB. The primary outcome was vaginal delivery. Secondary outcomes were a favorable cervix (Bishop score >6) after 24 h, the time from device insertion to delivery, and composite maternal and neonatal morbidity.

RESULTS

In total, 135 consecutive women were analyzed (107 CRB, 79.3%; 28 dinoprostone vaginal insert, 20.7%). Vaginal delivery (86 [80.4%] after CRB vs 19 [67.9%] after dinoprostone vaginal insert; P = 0.248), favorable cervix within 24 h after device placement (52 [48.6%] vs 17 [60.7%]; P = 0.264), and maternal morbidity (12 [11.2%] vs 4 [14.3%]; P = 0.646) were similar between the groups. The time from device insertion to delivery also did not differ between the groups. Neonatal morbidity was significantly higher after the dinoprostone vaginal insert (11 [39.3%] vs 20 [18.7%]; P = 0.030). Cervical ripening using the dinoprostone vaginal insert, compared with the CRB, was significantly associated with neonatal morbidity (adjusted odds ratio 4.00, 95% confidence interval 1.34-12.5), but not with maternal morbidity (adjusted odds ratio 1.23, 95% confidence interval 0.30-4.38).

CONCLUSIONS

Vaginal delivery, a favorable cervix after 24 h, the time from device insertion to delivery, and maternal morbidity did not significantly differ between the CRB and the dinoprostone vaginal insert for cervical ripening in obese women at term. Nevertheless, neonatal morbidity was significantly associated with the dinoprostone vaginal insert, compared with the CRB, among obese women who required cervical ripening at term.

Methods for the induction of labor: efficacy and safety

This review assessed the efficacy and safety of pharmacologic agents (prostaglandins, oxytocin, mifepristone, hyaluronidase, and nitric oxide donors) and mechanical methods (single- and double-balloon catheters, laminaria, membrane stripping, and amniotomy) and those generally considered under the rubric of complementary medicine (castor oil, nipple stimulation, sexual intercourse, herbal medicine, and acupuncture). A substantial body of published reports, including 2 large network meta-analyses, support the safety and efficacy of misoprostol (PGE1) when used for cervical ripening and labor induction. Misoprostol administered vaginally at doses of 50 μg has the highest probability of achieving vaginal delivery within 24 hours. Regardless of dosing, route, and schedule of administration, when used for cervical ripening and labor induction, prostaglandin E2 seems to have similar efficacy in decreasing cesarean delivery rates. Globally, although oxytocin represents the most widely used pharmacologic agent for labor induction, its effectiveness is highly dependent on parity and cervical status. Oxytocin is more effective than expectant management in inducing labor, and the efficacy of oxytocin is enhanced when combined with amniotomy. However, prostaglandins administered vaginally or intracervically are more effective in inducing labor than oxytocin. A single 200-mg oral tablet of mifepristone seems to represent the lowest effective dose for cervical ripening. The bulk of the literature assessing relaxin suggests this agent has limited benefit when used for this indication. Although intracervical injection of hyaluronidase may cause cervical ripening, the need for intracervical administration has limited the use of this agent. Concerning the vaginal administration of nitric oxide donors, including isosorbide mononitrate, isosorbide, nitroglycerin, and sodium nitroprusside, the higher incidence of side effects with these agents has limited their use. A synthetic hygroscopic cervical dilator has been found to be effective for preinduction cervical ripening. Although a pharmacologic agent may be administered after the use of the synthetic hygroscopic dilator, in an attempt to reduce the interval to vaginal delivery, concomitant use of mechanical and pharmacologic methods is being explored. Combining the use of a single-balloon catheter with dinoprostone, misoprostol, or oxytocin enhances the efficacy of these pharmacologic agents in cervical ripening and labor induction. The efficacy of single- and double-balloon catheters in cervical ripening and labor induction seems similar. To date, the combination of misoprostol with an intracervical catheter seems to be the best approach when balancing delivery times with safety. Although complementary methods are occasionally used by patients, given the lack of data documenting their efficacy and safety, these methods are rarely used in hospital settings.

Methods of induction of labor in women with obesity: A secondary analysis of two multicenter randomized controlled trials

INTRODUCTION

Obesity is an increasing public health concern worldwide and can lead to more complications in pregnancy and childbirth. Women with obesity more often require induction of labor for various indications. The aim of this study is to assess which method of induction of labor is safest and most effective in women with obesity.

MATERIAL AND METHODS

This is a secondary analysis of two randomized controlled trials about induction of labor. Women with a term singleton pregnancy in cephalic presentation, an unfavorable cervix, intact membranes and without a previous cesarean section were randomly allocated to cervical priming with a Foley catheter or vaginal prostaglandin-E2-gel (PROBAAT-I) or a Foley catheter or oral misoprostol (PROBAAT-II). The inclusion and exclusion criteria for the studies were identical. Induction methods were compared in women with obesity (body mass index ≥30.0). Main outcomes were cesarean section and postpartum hemorrhage (blood loss >1000 mL).

RESULTS

A total of 2664 women, were included in the trials, 517 of whom were obese: 254 women with obesity received a Foley catheter, 176 oral misoprostol and 87 prostaglandin E2 (PGE2). A cesarean section was performed in 29.1% of women allocated to Foley vs 22.2% in the misoprostol and 23.0% in the PGE2 groups. Comparisons between groups revealed no statistically significant differences: the relative risk [RR] was 1.31 (95% confidence interval [CI] 0.94-1.84) in the Foley vs misoprostol group and 1.27 (95% CI 0.83-1.95) in the Foley vs PGE2 group. The rates of postpartum hemorrhage were comparable (10.6%, 11.4% and 6.9%, respectively; P = 0.512). In women with obesity, more often a switch to another method occurred in the Foley group, (20.1% vs 6.3% in misoprostol vs 1.1% in the PGE2 group; P < 0.001). The risk of a failed Foley placement was higher in women with obesity than in women without obesity (8.3% vs 3.2%; adjusted odds ratio 3.12, 95% CI 1.65-5.90).

CONCLUSIONS

In women with obesity we found a nonsignificant trend towards an increased rate of cesarean sections in the group induced with a Foley catheter compared to oral misoprostol; however, the study lacked power for this subgroup analysis. The finding of a higher risk of failed placement of a Foley catheter in women with obesity can be used in shared decision making.

The association between maternal colonization with Group B Streptococcus and infectious morbidity following transcervical Foley catheter-assisted labor induction

OBJECTIVES

To determine whether maternal colonization with Group B Streptococcus increases the risk for infectious morbidity following transcervical Foley catheter-assisted cervical ripening.

METHODS

A retrospective cohort study comparing infectious morbidity and other clinical outcomes by Group B Streptococcus colonization status between all women with singleton pregnancies who underwent Foley catheter-assisted cervical ripening labor induction at a single tertiary medical center during 2011-2021. Multivariable logistic regression explored the relationship between Group B Streptococcus colonization to adverse outcomes while adjusting for relevant clinical variables.

RESULTS

A total of 4,409 women were included of whom 886 (20.1 %) were considered Group B Streptococcus carriers and 3,523 (79.9 %) were not. Suspected neonatal sepsis rate was similar between Group B Streptococcus carriers and non-carriers (5.2 vs. 5.0 %, respectively, p=0.78). Neonatal sepsis was confirmed in 7 (0.02 %) cases, all born to non-carriers. Group B Streptococcus carriers had a higher rate of maternal bacteremia compared to non-carriers (1.2 vs. 0.5 %, respectively, p=0.01). Group B Streptococcus colonization was independently associated with maternal bacteremia (adjusted odds ratio 3.05; 95 %CI 1.39, 6.66).

CONCLUSIONS

Group B Streptococcus colonization among women undergoing Foley catheter-assisted cervical ripening does not seem to increase the risk for neonatal infection. However, higher rates of maternal bacteremia were detected.

Predictive Factors for Successful Cervical Ripening among Women with Gestational Diabetes Mellitus at Term: A Prospective Study

The purpose of this prospective cohort study is to identify the predictive factors for vaginal delivery among women (n = 146) who underwent cervical ripening using a dinoprostone insert (PG) alone (13.7%), cervical ripening balloon (CRB) alone (52.7%), oral misoprostol (M) alone (4.1%), or repeated methods (R, 29.5%) for gestational diabetes mellitus (GDM) at term, and to analyze maternal and neonatal morbidity outcomes according to the method for cervical ripening. After cervical ripening, vaginal delivery occurred in 84.2% (n = 123) and was similar among groups (90.0% after PG, 83.1% after CRB, 83.3% after M, and 83.7% after R; p = 0.89). After a multivariable logistic regression analysis adjusted for potential confounders, the internal cervical os being open before cervical ripening was a predictor of vaginal delivery (adjusted odds ratio (OR) of 4.38, 95% confidence index (CI) of 1.62-13.3, p = 0.03), and previous cesarean delivery was a predictor of cesarean delivery (aOR of 7.67, 95% CI of 2.49-24.00, p < 0.01). Birthweight was also significantly associated with cesarean delivery (aOR of 1.15, 95% CI of 1.03-1.31, p = 0.02). The rates of maternal and neonatal morbidity outcomes were 10.9% (n = 16) and 19.9% (n = 29), respectively, and did not differ according to the mode of delivery and to the method used for cervical ripening. Identifying these specific high-risk women (previous cesarean delivery and internal cervical os being closed before cervical ripening) for cesarean delivery among women who underwent cervical ripening for GDM at term is important and practical for all physicians to make a decision in partnership with women.

Randomized controlled trial comparing efficacy of a combination regime containing two cervical sensitizers (mifepristone + Foley's catheter) versus single agent mifepristone or Foley's catheter for labor induction in women attempting TOLAC at late third trimester with a dead fetus in utero

Randomized controlled trial comparing efficacy of a combination regime containing two cervical sensitizers (mifepristone + Foley's catheter) versus single agent mifepristone or Foley's catheter for labor induction in women attempting TOLAC at late third trimester with a dead fetus in utero.

AIM

To compare efficacy and safety of a new combination regime comprising of two cervical sensitizers used simultaneously with single agents, for labor induction in women attempting TOLAC at ≥34 weeks' gestation with a dead fetus.

METHOD

This was a multiarm randomized controlled trial (RCT) where participants received one of the three regimes-single agent oral Mifepristone 200 mg, intracervical Foley's catheter (16 Fr size, filled with 40 mL normal saline after intracervical instillation), and combination regime consisting of both used simultaneously. Number of women undergoing vaginal birth within 48 h of induction (VB48 ) was the primary outcome compared between groups.

RESULTS

VB48 was higher in participants on combination regime in comparison to participants on Foley's catheter (54 vs. 42). Total vaginal births were higher in participants on combination regime compared to both single agents (58 vs. 48 and 44). Duration and dose of oxytocin augmentation was lower in participants on combination regime compared to both single agents. Induction birth interval was short in participants on combination regime compared to those on Foley's catheter. Maternal complications between groups were similar.

CONCLUSION

Combination of cervical sensitizers for labor induction in late third trimester among women with dead fetus attempting TOLAC resulted in higher proportion of vaginal births and might reduce risk of scar dehiscence due to requirement of a lower dose of oxytocin for augmentation.

Is there a difference in labor patterns after induction with prostaglandins and double-balloon catheters?

BACKGROUND

Labor progression curves are believed to differ between spontaneous and induced labors. However, data describing labor progression patterns with different modes of induction are insufficient.

OBJECTIVE

This study aimed to compare the progress patterns between labors induced with slow-release prostaglandin E2 vaginal analogue and those induced with a double-balloon catheter.

STUDY DESIGN

This retrospective cohort study included all nulliparous women who delivered at term and who underwent cervical ripening with prostaglandin E2 vaginal analogue or a double-balloon catheter from 2013 to 2021 in a tertiary hospital in Israel. Included in the analysis were women who achieved 10 cm cervical dilatation. The time intervals between centimeter-to-centimeter changes were evaluated.

RESULTS

A total of 1087 women were included of whom 786 (72.3%) were induced using prostaglandin E2 vaginal analogue and 301 (27.7%) were induced using a double-balloon catheter. The time from induction to birth was similar between the groups (32.5 hours for the prostaglandin E2 vaginal analogue group [5th-95th percentiles, 6.5-153.8] vs 29.2 hours for the double-balloon group [5th-95th percentiles, 9.1-157.1]; P=.100). The median time of the latent phase (2-6 cm dilation) was longer for the double-balloon catheter group than for the prostaglandin E2 vaginal analogue group (7.3 hours [5th-95th percentiles, 5.6-14.5] vs 6.0 hours [5th-95th percentiles, 2.4-18.8]; P=.042). The median time of active labor (6-10 cm dilatation) was similar between groups (1.9 hours [5th-95th percentiles, 0.3-7.4] for the prostaglandin E2 vaginal analogue group vs 2.3 hours [5th-95th percentiles, 0.3-6.5] for the double-balloon catheter group; P=.307).

CONCLUSION

Deliveries subjected to cervical ripening with a double-balloon catheter were characterized by a slightly longer latent phase than deliveries induced by prostaglandin E2 vaginal analogue. After reaching the active phase of labor, the mode of cervical ripening did not influence the labor progress pattern.

Predictors of vaginal delivery following balloon catheter for labor induction in women with one previous cesarean

BACKGROUND

The aim of this study was to estimate predictors for vaginal birth following balloon catheter induction of labor (IOL) in women with one previous cesarean section (CS) and an unfavorable cervix.

METHODS

This 4-year retrospective cohort study was conducted in Longhua District Central Hospital in Shenzhen China, between January 2015 and December 2018. Patients with one previous CS and a current singleton-term pregnancy who underwent balloon catheter cervical ripening and IOL were enrolled. Univariate analysis was used to identify predictive factors associated with vaginal birth after cesarean section (VBAC). Binary logistic regression was further used to identify which factors were independently associated with the outcome measure. The primary outcome was VBAC, which was a successful trial of labor after cesarean delivery (TOLAC) following IOL.

RESULTS

A total of 69.57% (208/299) of the women who planned for IOL had VBAC. In the final binary logistic regression equation, lower fetal weight (< 4000 g) (odds ratio [OR]5.26; 95% confidence interval [CI] 2.09,13.27), lower body mass index (BMI,<30 kg/m²) (OR 2.27; CI 1.21, 4.26), Bishop score after cervical ripening > 6 (OR 1.94; CI 1.37, 2.76) remained independently associated with an increased chance of VBAC.

CONCLUSIONS

The influencing factors of VBAC following IOL were fetal weight, BMI, and Bishop score after cervical ripening. Adequate individualized management and assessment of the IOL may help improve the VBAC rate.

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.

The influence of various induction methods on adverse outcomes in small for gestational age neonates: A secondary analysis of the PROBAAT 1 and 2 trials

OBJECTIVE

To evaluate the safety aspects of different induction methods in pregnancies with small-for-gestational-age neonates.

STUDY DESIGN

This was a secondary analysis of two previously reported multicenter, randomized controlled trials conducted in the Netherlands. In the original trials, women were randomized to either a 30 cc Foley catheter, vaginal prostaglandin E2 (PROBAAT-1) or oral misoprostol (PROBAAT-2). A total of 425 patients with a term, singleton pregnancy in cephalic presentation with an indication for labor induction and a small-for-gestational-age neonate were included in this secondary analysis. Our primary outcome was a composed adverse neonatal outcome of Apgar score < 7 after 5 min and/or a pH in the umbilical artery < 7.05 and/or NICU admission. Secondary outcomes were mode of birth, operative birth for fetal distress and pH < 7.10 in the umbilical artery. For these outcome measures, multivariate as well as bivariate analyses were performed.

RESULTS

An adverse neonatal outcome occurred in 4.7 % (10/214) induction with a Foley catheter, versus 12.8 % (19/149) after misoprostol (RR 0.36; 95 % CI 0.17-0.76) and 4.7 % (3/64) after Prostaglandin E2 (RR 0.98; 95 %CI 0.28-3.51). For individual components of the composed outcome of adverse events, a difference was found between a Foley catheter and misoprostol for Apgar score < 7 at 5 min (0.5 % versus 3.4; RR 0.14; 95 %CI 0.02-1.16) and NICU admission (1.9 % versus 6.1 %; RR 0.31; 0.10-0.97). No differences were found for mode of birth.

CONCLUSIONS

For women who gave birth to a small-for-gestational-age neonate, a Foley catheter is probably a safer induction method compared to oral misoprostol.

Evidence-Based Approaches to Labor Induction

Importance

The induction rate continues to increase in the United States placing pressure on the health care system with increasing cost and time spent on labor and delivery. Most labor induction regimens have evaluated uncomplicated singleton-term gestations. Unfortunately, the optimal labor regimens of medically complicated pregnancies have not been well described.

Objective

The aim of this study was to review the current available evidence regarding the various labor induction regimens and understand the evidence that exists for induction regimens in complicated pregnancies.

Evidence Acquisition

Data were acquired by a literature search on PubMed, ClinicalTrials.gov, the Cochrane Review database, the most recent American College of Obstetricians and Gynecologists practice bulletin on labor induction, and a review of the most recent edition on widely used obstetric texts for key words related to labor induction.

Results

Many heterogeneous clinical trials exist examining various labor induction regimens such as prostaglandin only, oxytocin only, or a combination of mechanical dilation with prostaglandins or oxytocin. Several Cochrane systematic reviews have been performed, which suggest a combination of prostaglandins and mechanical dilation results in an improved time to delivery when compared with single-use methods. Evaluating pregnancies complicated by maternal or fetal conditions, there exist retrospective cohorts describing significantly different labor outcomes. Although a few of these populations have planned or active clinical trials, most do not have an optimal labor induction regimen described.

Conclusions and Relevance

Most induction trials are significantly heterogeneous and limited to uncomplicated pregnancies. A combination of prostaglandins and mechanical dilation may result in improved outcomes. Complicated pregnancies have significantly different labor outcomes; however, almost none have well-described labor induction regimens.

Evaluation of mechanical and nonmechanical methods of cervix ripening in women with premature rupture of membranes: a randomized controlled trial

BACKGROUND

Premature rupture of membranes occurs in 8% of pregnancies. In the absence of spontaneous labor, induction of labor is considered an appropriate strategy for term pregnant women with premature rupture of membranes. There are several approaches for preinduction cervical ripening, including mechanical methods, such as Foley catheterization, and nonmechanical methods, such as oral misoprostol.

OBJECTIVE

This study aimed to evaluate and compare the effects of oral misoprostol and Foley catheterization in pregnant women with premature rupture of membranes at ≥34 weeks of gestation who underwent induction of labor.

STUDY DESIGN

A randomized clinical trial was conducted. The inclusion criteria included nulliparous and multiparous pregnant women at ≥34 weeks of gestation with singleton pregnancies, cephalic presentation, and confirmed amniotic fluid leakage for more than 60 minutes. A total of 104 participants were randomly allocated into 2 groups, one receiving sublingual misoprostol and the other receiving transcervical Foley catheter for cervical ripening. The primary outcome was time from intervention to delivery, and the secondary outcomes included delivery method, maternal and neonatal results (chorioamnionitis, Apgar score, neonatal sepsis, and asphyxia), and arterial blood gas analysis of the umbilical cord.

RESULTS

The mean time from induction of labor to delivery (11.6±1.98 hours for Foley catheter vs 10.16±2.35 hours for misoprostol; P=.007) and the median duration of cervical ripening (4.5 hours [interquartile range, 0.0-6.0] for Foley catheter vs 4.0 hours [interquartile range, 1.5-6.0] for misoprostol; P=.04) were longer in the Foley catheter group than in the misoprostol group. There was no statistically significant difference in the cesarean delivery rate between the 2 groups (29.6% for Foley catheter vs 38.5% for misoprostol; P=.2). There was no case of chorioamnionitis or asphyxia in the 2 groups. There was no significant difference between the 2 groups in terms of umbilical cord pH and the 1- and 5-minute Apgar scores (P=.1, P=.4, and P=.1); nevertheless, these values were higher in the Foley catheter group. There was no statistically significant difference among additional secondary outcomes.

CONCLUSION

In premature rupture of membranes cases, cervical ripening with a Foley catheter was associated with a longer duration of ripening and time from induction to delivery than cervical ripening with misoprostol. The cesarean delivery rate and the maternal and neonatal infection rates were not different between these methods.

Intra-cervical Foley Balloon Catheter Versus Prostaglandins for the Induction of Labour: A Literature Review

Labour induction involves helping a woman to start her labour, before labour begins on its own, for a vaginal birth with the aid of artificial methods, such as medications or other medical techniques. Labour induction is done in cases where extending the pregnancy can threaten the mother or her baby's health, and delivery should result in better outcomes than continuing the pregnancy. Currently, nearly 25% of babies are born by labour induction in economically developed countries. It is often necessary in certain situations to induce labour by using ripening techniques that not only soften the cervix but also make it thin and dilated. Mechanical or pharmacological approaches are used for the artificial induction of labour. Because research articles evaluating the safety and efficacy of various ripening techniques of the cervix vary in terms of their findings, it remains uncertain as to which is the best way to induce labour. In light of this, to find out the most popular interventions for ripening of the cervix during labour induction, we performed a review of the literature that compares the use of a Foley catheter and prostaglandins (misoprostol and dinoprostone). Our findings show that using misoprostol orally is much better than using it vaginally. Foley catheter proved to be the least effective induction technique, despite the fact that it offers the lowest risk.

Predictors of efficacy for cervical ripening among the Bishop score criteria in nulliparous women at term

OBJECTIVE

To determine predictors of efficacy for cervical ripening among the Bishop score criteria in nulliparous women at term.

METHOD

Prospective observational study of nulliparous women with singleton term fetuses in vertex presentation, intact membranes, and an unfavorable cervix (Bishop score < 6) who underwent cervical ripening with a cervical-ripening balloon (CRB; n = 47) or dinoprostone vaginal insert (PG; n = 28). The authors analyzed Bishop score criteria (dilatation, effacement, fetal station, consistency, position) before and after device removal. Primary outcome was favorable cervix (Bishop score ≥ 6) after device removal. Secondary outcomes were vaginal delivery, modification of Bishop score criteria, and perinatal morbidity.

RESULTS

Rates of favorable cervix after cervical ripening were similar between groups (66.7% with CRB vs. 59.3% with PG; P = 0.526). Vaginal delivery (76.6% vs. 78.6%; P = 0.843) and perinatal morbidity did not differ between groups. CRB appeared to be more effective than PG in increasing consistency (+0.7 ± 0.2 vs. +0.3 ± 0.2; P = 0.001) and dilatation of the cervix (+1.3 ± 0.3 vs. +0.9 ± 0.3; P = 0.005). No Bishop score criterion was found as a significant predictor for vaginal delivery.

CONCLUSION

CRB seems to be more effective than PG in increasing the consistency and dilatation of the cervix. Efficacy of CRB and PG for vaginal delivery was similar.

Balloon catheters versus vaginal prostaglandins for labour induction (CPI Collaborative): an individual participant data meta-analysis of randomised controlled trials

BACKGROUND

Induction of labour is one of the most common obstetric interventions globally. Balloon catheters and vaginal prostaglandins are widely used to ripen the cervix in labour induction. We aimed to compare the effectiveness and safety profiles of these two induction methods.

METHODS

We did an individual participant data meta-analysis comparing balloon catheters and vaginal prostaglandins for cervical ripening before labour induction. We systematically identified published and unpublished randomised controlled trials that completed data collection between March 19, 2019, and May 1, 2021, by searching the Cochrane Library, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, and PubMed. Further trials done before March 19, 2019, were identified through a recent Cochrane review. Data relating to the combined use of the two methods were not included, only data from women with a viable, singleton pregnancy were analysed, and no exclusion was made based on parity or membrane status. We contacted authors of individuals trials and participant-level data were harmonised and recoded according to predefined definitions of variables. Risk of bias was assessed with the ROB2 tool. The primary outcomes were caesarean delivery, indication for caesarean delivery, a composite adverse perinatal outcome, and a composite adverse maternal outcome. We followed the intention-to-treat principle for the main analysis. The primary meta-analysis used two-stage random-effects models and the sensitivity analysis used one-stage mixed models. All models were adjusted for maternal age and parity. This meta-analysis is registered with PROSPERO (CRD42020179924).

FINDINGS

Individual participant data were available from 12 studies with a total of 5460 participants. Balloon catheters, compared with vaginal prostaglandins, did not lead to a significantly different rate of caesarean delivery (12 trials, 5414 women; crude incidence 27·0%; adjusted OR [aOR] 1·09, 95% CI 0·95-1·24; I²=0%), caesarean delivery for failure to progress (11 trials, 4601 women; aOR 1·20, 95% CI 0·91-1·58; I²=39%), or caesarean delivery for fetal distress (10 trials, 4441 women; aOR 0·86, 95% CI 0·71-1·04; I²=0%). The composite adverse perinatal outcome was lower in women who were allocated to balloon catheters than in those allocated to vaginal prostaglandins (ten trials, 4452 neonates, crude incidence 13·6%; aOR 0·80, 95% CI 0·70-0·92; I²=0%). There was no significant difference in the composite adverse maternal outcome (ten trials, 4326 women, crude incidence 22·7%; aOR 1·02, 95% CI 0·89-1·18; I²=0%).

INTERPRETATION

In induction of labour, balloon catheters and vaginal prostaglandins have comparable caesarean delivery rates and maternal safety profiles, but balloon catheters lead to fewer adverse perinatal events.

FUNDING

Australian National Health and Medical Research Council and Monash Health Emerging Researcher Fellowship.

Using the WHO-INTEGRATE evidence-to-decision framework to develop recommendations for induction of labour

BACKGROUND

In 2019, WHO prioritized updating recommendations relating to three labour induction topics: labour induction at or beyond term, mechanical methods for labour induction, and outpatient labour induction. As part of this process, we aimed to review the evidence addressing factors beyond clinical effectiveness (values, human rights and sociocultural acceptability, health equity, and economic and feasibility considerations) to inform WHO Guideline Development Group decision-making using the WHO-INTEGRATE evidence-to-decision framework, and to reflect on how methods for identifying, synthesizing and integrating this evidence could be improved.

METHODS

We adapted the framework to consider the key criteria and sub-criteria relevant to our intervention. We searched for qualitative and other evidence across a variety of sources and mapped the eligible evidence to country income setting and perspective. Eligibility assessment and quality appraisal of qualitative evidence syntheses was undertaken using a two-step process informed by the ENTREQ statement. We adopted an iterative approach to interpret the evidence and provided both summary and detailed findings to the decision-makers. We also undertook a review to reflect on opportunities to improve the process of applying the framework and identifying the evidence.

RESULTS

Using the WHO-INTEGRATE framework allowed us to explore health rights and equity in a systematic and transparent way. We identified a lack of qualitative and other evidence from low- and middle-income settings and in populations that are most impacted by structural inequities or traditionally excluded from research. Our process review highlighted opportunities for future improvement, including adopting more systematic evidence mapping methods and working with social science researchers to strengthen theoretical understanding, methods and interpretation of the evidence.

CONCLUSIONS

Using the WHO-INTEGRATE evidence-to-decision framework to inform decision-making in a global guideline for induction of labour, we identified both challenges and opportunities relating to the lack of evidence in populations and settings of need and interest; the theoretical approach informing the development and application of WHO-INTEGRATE; and interpretation of the evidence. We hope these insights will be useful for primary researchers as well as the evidence synthesis and health decision-making communities, and ultimately contribute to a reduction in health inequities.

Prognostic factors for successful induction of labor in intrauterine growth restriction after 36 weeks of gestation

OBJECTIVE

In comparison to eutrophic fetuses, intra uterine growth restriction fetuses (IUGR) have a higher risk of perinatal morbi-mortality. There are no guidelines on the labor induction of labor (IOL) method to be performed in IUGR. The main objective was to determine fetal and maternal predictive factors of successful induction in IUGR fetuses from 36 weeks. Study design We conducted a retrospective cohort single-center study including 320 women with a cephalic fetal presentation. Labour was induced after 36 weeks for suspected IUGR between January 2013 and December 2019.

RESULTS

Among the 320 patients, 246 were delivered vaginally (76.9 %) and 74 had a cesarean (23.1 %). Prognostic factors for successful IUGR induction were nonscarring uterus (OR 8.41; 95 %CI [2.92-24.21]), absence of preeclampsia (OR 7.14; 95 %CI [2.42-21.03]), multiparity (OR 4.32; 95 %CI [1.83-10.18]), normal fetal heart rate before IOL (OR 2.99; 95 %CI [1.24-7.22]) and BMI < 30 (OR 3.54; 95 %CI [1.62-7.72]). Doppler abnormalities, method and number of line of IOL, cervical evaluation were not significant in our study.

CONCLUSION

The prognostic factors for successful IUGR induction are essentially maternal. Thus, a low BMI, multiparity, nonscarring uterus, absence of preeclampsia, and a normal FHR are good prognostic factors in IUGR induction.

[Induction of labour with oral misoprostol versus vaginal misoprostol: A before-after study]

OBJECTIVE

The rate of induction of labor represented 22 % of deliveries in 2016 in France. Oral misoprostol (Angusta®) was marketed in France in the last quarter of 2018. The objective of our study was to compare the efficacy and safety of induction of labor with oral misoprostol compared to vaginal misoprostol in women with an unripe cervix.

MATERIAL AND METHODS

We carried out a retrospective study before and after the implementation of oral misoprostol including all women with an unripe cervix who benefited from an induction of labor with a viable infant in vertex presentation, without uterine scar. During the first two-year period, women received 50μg of misoprostol in the posterior fornix, repeated 6hours later if needed. If labor had not started after 24hours, women received another dose of 50μg, which was repeated every 4hours until labor was established, up to a total dose of 150μg. During the second two-year period, women received two tablets of oral misoprostol 25μg every four hours if necessary, up to a total dose of 200μg. The primary endpoints were mode of delivery and neonatal safety.

RESULTS

During the two study periods, 1199 women received vaginal misoprostol and 1199 women received oral misoprostol including. The cesarean delivery rate was 21.8% during the first period and 21,3% during the second period (P=0.83). A 5-minutes Apgar score<7 was observed in 23 (1.9%) and 14 (1.2%) newborns in the vaginal misoprostol and oral misoprostol groups (P=0.14), respectively. An arterial cord pH<7.00 was observed in 6 (0.5%) and 7 (0.6%) newborns (P=0.99), respectively.

CONCLUSION

Oral misoprostol administered at the dose of 50μg every 4hours (up to a total dose of 200μg) is as effective and safe as the vaginal misoprostol to induce labor in women with an unripe cervix.

Mechanical dilatation of the stenosed cervix under local anesthesia: A prospective case series

AIM

Cervical stenosis is traditionally managed by mechanical dilatation under general anesthesia (GA). We aimed to assess the safety, effectiveness, and patient acceptability of dilatation in the outpatient setting under local anesthesia (LA).

METHODS

Data were collected prospectively from all patients attending the outpatient department with cervical stenosis from March 20, 2015 to September 23, 2020. Mechanical dilatation of the cervix was performed using Hegar dilators under LA. Subsequent colposcopic assessment, cytology, histology, and management were recorded.

RESULTS

One hundred forty-nine cases were referred for cervical dilatation, 63 (43%) of which had complete stenosis. One hundred eighteen (79%) patients had previously undergone cervical procedures. Successful dilatation under LA was achieved in 119 (83%) patients; 5 (3%) declined (requesting GA), 6 (4%) did not tolerate speculum examination, and 19 (13%) had unsuccessful procedures. The median Hegar size used was 8 mm. Dilatation under LA was acceptable in 93% attempted procedures. Thirteen episodes of restenosis were recorded with no major adverse events. Younger age (p = 0.045) and severe (compared to complete) stenosis (p < 0.0001) were associated with procedure success, with improved results over time (p = 0.003). Successful dilatation permitted cervical assessment; eight patients required cervical excisions, two underwent hysterectomies, with one confirmed case of adenocarcinoma.

CONCLUSION

Rigid cervical dilatation in the outpatient setting provides effective, instantaneous treatment for women who have failed cytological or colposcopic assessment. For the vast majority of women, the procedure was well tolerated and preferred to using GA. However, given that 1 in 10 women experienced restenosis, patients should be counseled about the possibility of requiring further management.

Outcome of Induction of Labor with Foley's Catheter in Women with Previous One Cesarean Section with Unfavorable Cervix: An Experience From a Tertiary Care Institute in South India

BACKGROUND

Induction of labor in women with previous cesarean section is associated by the fear of scar rupture, resulting in high rates of repeat scheduled cesarean section. Mechanical methods are being advocated as a safe method. We present our experience of vaginal birth rates and safety profile with single-balloon Foley's catheter for induction of labor in women with previous one cesarean section.

METHODS

We studied 96 women admitted in Women and Children Hospital JIPMER, India, with a previous cesarean section at term having unfavorable cervix and undergoing induction of labor. Foley's catheter inflated to 60 ml was used for cervical ripening for 24 h followed by strict oxytocin infusion protocol.

RESULTS

The mean Bishop score before induction of labor was 3.3 ± 0.88. Ripening with Foley's catheter resulted in mean improvement in the Bishop score by 2.56 ± 0.67. Forty-seven percent women spontaneously expelled the Foley's catheter, and 53.1% achieved contractions spontaneously. The successful vaginal birth rate was 40%. Emergency caesarean section was more likely in women with poor post ripening Bishop score, meconium stained liquor and abnormal fetal heart rate pattern during labour. There was one scar dehiscence, one neonate with low Apgar score. There was no rupture uterus.

CONCLUSION

Induction of labor with Foley's catheter resulted in a 40% successful vaginal birth rate and was found to be safe with only one scar dehiscence and no perinatal or maternal mortality. There was no perinatal or maternal mortality.

Prospective observational study investigating the effectiveness, safety, women’s experiences and quality of life at 3 months regarding cervical ripening methods for induction of labor at term—The MATUCOL study protocol

Background

The purposes of successful induction of labor (IOL) are to shorten the time for IOL to delivery, increase the vaginal delivery rate, and reduce the rate of maternal and neonatal morbidity. In cases of unfavorable cervix (Bishop score <6), cervical ripening is advised to improve vaginal delivery rate. It may be initiated by mechanical (double balloon catheter (DBC), synthetic osmotic dilator) or pharmacologic (prostaglandins) methods, and the problem is complex due to the multitude of cervical ripening methods. We are constantly looking for the optimal protocol of cervical ripening for each woman. The present study aims to elucidate whether cervical ripening method is associated with increase rate of vaginal delivery, good women’s experience and unaltered long-term quality of life after cervical ripening at term regarding maternal and obstetric characteristics.

Methods and design

The MATUCOL study is a monocentric, prospective, observational study of all consecutive women who required cervical ripening (Bishop score <6) using different methods (DBC, vaginal dinoprostone, oral misoprostol) with a live fetus at term (≥37 weeks) between January 2020 and August 2021. The outcomes will be mode of delivery, maternal and neonatal morbidity, discomfort/pain assessments during cervical ripening, women’s experience and satisfaction, and the impact of cervical ripening on the health-related quality of life at 3 months. If it reports a significant efficacy/safety/perinatal morbidity/women’s satisfaction/quality of life at 3 months post-delivery associated with a method of cervical ripening in a specific situation (gestational and/or fetal disease) using a multivariate analysis, its use should be reconsidered in clinical practice.

Discussion

This study will reveal that some cervical ripening methods will be more effectiveness, safe, with good women’s experiences and QOL at 3 months compared to others regarding maternal and obstetric characteristics.

Trial registration

This study is being performed at La Roche sur Yon Hospital following registration as GNEDS on January 8, 2020.

Nomogram predicting cesarean delivery undergoing induction of labor among high-risk nulliparous women at term: a retrospective study

Background

Our aim was to create and validate a nomogram predicting cesarean delivery after induction of labor among nulliparous women at term.

Methods

Data were obtained from medical records from Nanjing Drum Tower Hospital. Nulliparous women with singleton pregnancies undergoing induction of labor at term were involved. A total of 2950 patients from Jan. 2014 to Dec. 2015 were served as derivation cohort. A nomogram was constructed by multivariate logistic regression using maternal, fetal and pregnancy characteristics. The predictive accuracy and discriminative ability of the nomogram were internal validated by 1000-bootstrap resampling, followed by external validation of a new dataset from Jan. 2016 to Dec. 2016.

Results

Logistic regression revealed nine predictors of cesarean delivery, including maternal height, age, uterine height, abdominal circumference, estimated fetal weight, indications for induction of labor, initial cervical consistency, cervical effacement and station. Nomogram was well calibrated and had an AUC of 0.73 (95% confidence interval [CI], 0.70-0.75) after bootstrap resampling for internal validation. The AUC in external validation reached 0.67, which was significantly higher than that of three models published previously (P<0.05).

Conclusions

This validated nomogram, constructed by variables that were obtained form medical records, can help estimate risk of cesarean delivery before induction of labor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04386-8.

Maternal and fetal characteristics for predicting risk of Cesarean section following induction of labor: pooled analysis of PROBAAT trials

OBJECTIVE

Induction of labor (IOL) is one of the most widely used obstetric interventions. However, one-fifth of IOLs result in Cesarean section (CS). We aimed to assess maternal and fetal characteristics that influence the likelihood of CS following IOL, according to the indication for CS.

METHODS

This was a secondary analysis of pooled data from four randomized controlled trials, including women undergoing IOL at term who had a singleton pregnancy and an unfavorable cervix, intact membranes and the fetus in cephalic presentation. The main outcomes of this analysis were CS for failure to progress (FTP) and CS for suspected fetal compromise (SFC). Restricted cubic splines were used to determine whether continuous maternal and fetal characteristics had a non-linear relationship with outcome. Optimal cut-offs for those characteristics with a non-linear pattern were determined based on the maximum area under the receiver-operating-characteristics curve. Adjusted odds ratios (aOR) were computed, using multivariable logistic regression analysis, for the associations between optimally categorized characteristics and outcome.

RESULTS

Of a total of 2990 women undergoing IOL, 313 (10.5%) had CS for FTP and 227 (7.6%) had CS for SFC. The risk of CS for FTP was increased in women aged 31-35 years compared with younger women (aOR, 1.51 (95% CI, 1.15-1.99)), in nulliparous compared with parous women (aOR, 8.07 (95% CI, 5.34-12.18)) and in Sub-Saharan African compared with Caucasian women (aOR, 2.09 (95% CI, 1.33-3.28)). Higher body mass index (BMI) increased incrementally the risk of CS for FTP (aOR, 1.06 (95% CI, 1.04-1.08)). High birth-weight percentile was also associated with an increased risk of CS due to FTP (aOR, 2.66 (95% CI, 1.74-4.07) for birth weight between the 80.0^th and 89.9^th percentiles and aOR, 4.08 (95% CI, 2.75-6.05) for birth weight ≥ 90^th percentile, as compared with birth weight between the 20.0^th and 49.9^th percentiles). For CS due to SFC, higher maternal age (aOR, 1.09 (95% CI, 1.05-1.12)) and BMI (aOR, 1.05 (95% CI, 1.03-1.08)) were associated with an incremental increase in risk. The risk of CS for SFC was increased in nulliparous compared with parous women (aOR, 5.91 (95% CI, 3.76-9.28)) and in South Asian compared with Caucasian women (aOR, 2.50 (95% CI, 1.23-5.10)). Birth weight < 10.0^th percentile increased significantly the risk of CS due to SFC (aOR, 1.93 (95% CI, 1.22-3.05)), as compared with birth weight between the 20.0^th and 49.9^th percentiles. Bishop score did not demonstrate a significant association with the risk of CS for FTP or for SFC.

CONCLUSIONS

In women undergoing IOL, maternal age, BMI, parity, ethnicity and birth-weight percentile are predictors of CS due to FTP and of CS due to SFC, but the direction and magnitude of the associations differ according to the indication for CS. These characteristics should be considered in combination with the Bishop score to stratify the risk of CS for different indications in women undergoing IOL. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Simultaneous use of high-volume Foley catheter (60 ml) and misoprostol for labor induction in nulliparous women: A randomized controlled trial

OBJECTIVE

To examine the simultaneous effect of high-volume Foley catheter (HVFC) (60 ml) and vaginal misoprostol on labor induction in nulliparous women.

METHODS

A randomized, double-blind, controlled trial was conducted among nulliparous post-date (>40 weeks) pregnant women between June and December 2019. At enrollment 100 women were randomized into each group (either HVFC and vaginal misoprostol or low-volume Foley catheter [LVFC] [30 ml] and vaginal misoprostol), for labor induction. Demographic and clinical data were collected at enrollment and delivery.

RESULTS

Women in the HVFC group had statistically significantly shorter induction to delivery interval (median 860 min, interquartile range [IQR] 840-940 min vs. 1160 min, IQR 1080-1320 min, P < 0.001) and duration of labor (median 615 min, IQR 600-680 min vs. 750, IQR 692.5-800 min, P < 0.001). Mode of vaginal delivery (n = 94 vs. n = 78, P = 0.002), number of doses of misoprostol required (median 2, IQR 1-2 vs. 2, IQR 1-3), and need of oxytocin augmentation (n = 22 vs. n = 39, P = 0.014 and P < 0.001), was significantly better in the HVFC group. However, there was no significant difference with respect to other maternal or neonatal outcomes.

CONCLUSION

Simultaneous use of HVFC and vaginal misoprostol for labor induction significantly shortens the induction to delivery interval and duration of labor in nulliparous women.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2019/05/019394 (http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=31554&EncHid=&userName=Foley%20catheter).

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.

Changes in local protocols on inpatient cervical priming and introduction of outpatient priming: A nationwide survey in the Netherlands

OBJECTIVE

The aims of this study are to assess (changes in) local procedures for inpatient cervical priming as part of induction of labor and to identify the implementation of outpatient cervical priming in the Netherlands.

METHODS

This survey study was conducted from October 2019 until January 2020; obstetricians of all 72 hospitals with a maternity unit in the Netherlands received a questionnaire. The questionnaire consisted of three parts: basic hospital data, local protocol on methods of inpatient induction of labor (IPI), local protocol for outpatient induction of labor (OPI).

RESULTS

A response was received from 66/72 hospitals, giving a response rate of 92%. For IPI the most preferred method was a Foley catheter (87.9%), 27.6% protocols switched to prostaglandins after day 1 if the cervix was not ripe yet. A prostaglandin gel or pessary was not the preferred method on day 1 but only used after 24 h in 5 hospitals (7.6%). OPI was offered in 53% (35/66 hospitals), all using a Foley catheter.

CONCLUSION

In the Netherlands, local protocols for IPI have shifted towards the use of a Foley catheter. More than half of the hospitals offer OPI. As safety and efficacy data of OPI are lacking, research on this topic is urgently warranted.

Cervical ripening at home or in-hospital-prospective cohort study and process evaluation (CHOICE) study: a protocol

INTRODUCTION

The aim of the cervical ripening at home or in-hospital-prospective cohort study and process evaluation (CHOICE) study is to compare home versus in-hospital cervical ripening to determine whether home cervical ripening is safe (for the primary outcome of neonatal unit (NNU) admission), acceptable to women and cost-effective from the perspective of both women and the National Health Service (NHS).

METHODS AND ANALYSIS

We will perform a prospective multicentre observational cohort study with an internal pilot phase. We will obtain data from electronic health records from at least 14 maternity units offering only in-hospital cervical ripening and 12 offering dinoprostone home cervical ripening. We will also conduct a cost-effectiveness analysis and a mixed methods study to evaluate processes and women/partner experiences. Our primary sample size is 8533 women with singleton pregnancies undergoing induction of labour (IOL) at 39+0 weeks' gestation or more. To achieve this and contextualise our findings, we will collect data relating to a cohort of approximately 41 000 women undergoing IOL after 37 weeks. We will use mixed effects logistic regression for the non-inferiority comparison of NNU admission and propensity score matched adjustment to control for treatment indication bias. The economic analysis will be undertaken from the perspective of the NHS and Personal Social Services (PSS) and the pregnant woman. It will include a within-study cost-effectiveness analysis and a lifetime cost-utility analysis to account for any long-term impacts of the cervical ripening strategies. Outcomes will be reported as incremental cost per NNU admission avoided and incremental cost per quality adjusted life year gained.

RESEARCH ETHICS APPROVAL AND DISSEMINATION

CHOICE has been funded and approved by the National Institute of Healthcare Research Health Technology and Assessment, and the results will be disseminated via publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN32652461.

Induction of labor using Foley catheter with weight attached versus without weight attached: A randomized control trial

OBJECTIVE

To assess the effectiveness in preventing cesarean section for failed induction by using Foley catheter for cervical ripening in comparison to Foley catheter with a weight attached to it.

METHODS

A randomized control trial conducted between November 2018 and July 2020, which looked at induction of labor with 30-ml Foley catheter in one arm and the Foley placed with a 500 ml weight attached to it in the other arm. Primary outcome was the cesarean section rate.

RESULTS

We randomized 399 women. Modes of delivery were similar in both groups. Numbers undergoing cesarean section for failed induction were higher in the group that underwent induction with Foley with weight but this was not statistically significant (45.7% vs 26.5%, P = 0.1). There was a shorter time to expulsion of the Foley with weight attached (mean ± standard deviation: 2.6 ± 3.3 h vs 10.9 ± 3.2 h, P < 0.001) but this did not translate into a difference in time to active labor or time to delivery.

CONCLUSION

Placing a weight at the end of the Foley catheter for induction of labor does not affect the time to delivery or the rate of cesarean deliveries, although there is faster expulsion of the Foley. Clinical trial registration no.: CTRI/2018/10/016154.

[Retrospective comparison of effectiveness of balloon catheter versus dinoprostone for cervical ripening]

OBJECTIVE

To compare the effectiveness and the safety of cervical ripening between two methods: the Cook double balloon catheter and the dinoprostone pessary (Propess 10mg).

METHODS

We performed a retrospective comparative study in a French maternity. We analyzed 404 women with induction of labour after 37 gestational weeks, with singleton cephalic live fetus, unscarred uterus, unruptured membranes, and Bishop score<6. The primary endpoint was the time between the start of the ripening and the delivery. Secondary endpoints include effectiveness and safety outcomes of the methods.

RESULTS

Compared to dinoprostone pessary, the balloon catheter was associated with a longer time to delivery (34.4±16.5 vs 25.5±15.3h; P<0.001). This difference is found in both primiparous and multiparous women. Balloon catheter is also associated with a smaller improvement of the Bishop score (2.5±2.1 vs 4.2±2.9 Bishop's points; P<0.001) and more failure to achieve delivery in 24h (32.3% vs 56.7%; P<0.001). There was no difference in mother and fetal safety.

CONCLUSION

In this retrospective study, cervical ripening using balloon catheter seems to lengthen the induction of labour. No difference in safety outcomes with dinoprostone was found.

Massive antepartum haemorrhage at insertion of Foley balloon catheter for induction of labour

Induction of labour using a balloon catheter is common practice throughout the world, often used in high-risk pregnancies due to the improved safety profile for the fetus compared with pharmacological methods. This report outlines the case of a 2500 mL antepartum haemorrhage on placement of a Foley catheter through the cervix at a secondary obstetric unit in New Zealand. An emergency caesarean section was carried out 20 min after the bleeding onset. No obvious cause for the bleeding was identified at caesarean. The mother required a blood transfusion, but otherwise, did well clinically; the infant required resuscitation at birth and went on to suffer a left middle cerebral artery stroke. At 6 months, he is assumed to have recovered with no long-term sequelae. A literature review has highlighted this was an unprecedented event. We hope to raise awareness of this rare catastrophic adverse outcome given the prevalence of balloon catheter induction.

Induction of labor with Foley catheter and risk of subsequent preterm birth: follow-up study of two randomized controlled trials (PROBAAT-1 and -2)

OBJECTIVE

To evaluate the rate of preterm birth (PTB) in a subsequent pregnancy in women who had undergone term induction using a Foley catheter compared with prostaglandins.

METHODS

This was a follow-up study of two large randomized controlled trials (PROBAAT-1 and PROBAAT-2). In the original trials, women with a term singleton pregnancy with the fetus in cephalic presentation and with an indication for labor induction were randomized to receive either a 30-mL Foley catheter or prostaglandins (vaginal prostaglandin E2 in PROBAAT-1 and oral misoprostol in PROBAAT-2). Data on subsequent ongoing pregnancies > 16 weeks' gestation were collected from hospital charts from clinics participating in this follow-up study. The main outcome measure was preterm birth < 37 weeks' gestation in a subsequent pregnancy.

RESULTS

Fourteen hospitals agreed to participate in this follow-up study. Of the 1142 eligible women, 572 had been allocated to induction of labor using a Foley catheter and 570 to induction of labor using prostaglandins. Of these, 162 (14%) were lost to follow-up. In total, 251 and 258 women had a known subsequent pregnancy > 16 weeks' gestation in the Foley catheter and prostaglandin groups, respectively. There were no differences in baseline characteristics between the groups. The overall rate of PTB in a subsequent pregnancy was 9/251 (3.6%) in the Foley catheter group vs 10/258 (3.9%) in the prostaglandin group (relative risk (RR), 0.93; 95% CI, 0.38-2.24), and the rate of spontaneous PTB was 5/251 (2.0%) vs 5/258 (1.9%) (RR, 1.03; 95% CI, 0.30-3.51).

CONCLUSION

In women with term singleton pregnancy, induction of labor using a 30-mL Foley catheter is not associated with an increased risk of PTB in a subsequent pregnancy, as compared to induction of labor using prostaglandins. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Outpatient Induction of Labor - Are Balloon Catheters an Appropriate Method?

As the number of labor inductions in high-income countries has steadily risen, hospital costs and the additional burden on obstetric staff have also increased. Outpatient induction of labor is therefore becoming increasingly important. It has been estimated that 20 – 50% of all pregnant women requiring induction would be eligible for outpatient induction. The use of balloon catheters in patients with an unripe cervix has been shown to be an effective and safe method of cervical priming. Balloon catheters are as effective as the vaginal administration of prostaglandin E ₂ or oral misoprostol. The advantage of using a balloon catheter is that it avoids uterine hyperstimulation and monitoring is less expensive. This makes balloon catheters a suitable option for outpatient cervical ripening. Admittedly, intravenous administration of oxytocin to induce or augment labor is required in approximately 75% of cases. Balloon catheters are not associated with a higher risk of maternal and neonatal infection compared to vaginal PGE ₂ . Low-risk pregnancies (e.g., post-term pregnancies, gestational diabetes) are suitable for outpatient cervical ripening with a balloon catheter. The data for high-risk pregnancies are still insufficient. The following conditions are recommended when considering an outpatient approach: strict selection of appropriate patients (singleton pregnancy, cephalic presentation, intact membranes), CTG monitoring for 20 – 40 minutes after balloon placement, the patient must be given detailed instructions about the indications for immediate readmission to hospital, and 24-hour phone access to the hospital must be ensured. According to reviewed studies, the balloon catheter remained in place between 12 hours (“overnight”) and 24 hours. The most common reason for readmission to hospital was expulsion of the balloon catheter. The advantages of outpatient versus inpatient induction of cervical ripening with a balloon catheter were the significantly shorter hospital stay, the lower costs, and higher patient satisfaction, with both procedures having been shown to be equally effective. Complication rates (e.g., vaginal bleeding, severe pain, uterine hyperstimulation syndrome) during the cervical ripening phase are low (0.3 – 1.5%); severe adverse outcomes (e.g., placental abruption) have not been reported. Compared to inpatient induction of labor using vaginal PGE ₂ , outpatient cervical ripening using a balloon catheter had a lower rate of deliveries/24 hours and a significantly higher need for oxytocin; however, hospital stay was significantly shorter, frequency of pain during the cervical ripening phase was significantly lower, and patientsʼ duration of sleep was longer. A randomized controlled study comparing outpatient cervical priming with a balloon catheter with outpatient or inpatient induction of labor with oral misoprostol would be of clinical interest.

Foley Bulb Added to an Oral Misoprostol Induction Protocol: A Cluster Randomized Trial

OBJECTIVE

To evaluate whether the induction of labor in term gravid women with cervical dilation 2 cm or less and intact membranes by using oral misoprostol preceded by transcervical Foley bulb placement results in a significantly increased vaginal delivery rate compared with the use of oral misoprostol alone.

METHODS

We randomized the induction method by week of admission to labor and delivery, with each week group described as a cluster in a block randomized design. Women with gestational age of 37 weeks or greater, cervical dilation 2 cm or less, intact membranes, and indication for labor induction were included. Study arms were either 100 micrograms of oral misoprostol after transcervical Foley bulb placement or 100 micrograms of oral misoprostol alone. The primary outcome was vaginal delivery with the first induction attempt. Secondary outcomes included time to delivery, clinical chorioamnionitis (maternal temperature of 38°C or greater during labor with or without fundal tenderness, without other identified cause), cesarean delivery indication, and adverse outcomes. We estimated that a sample size of 1,077 per arm was needed to detect a 5% increase in vaginal delivery rate with a type I error of 5% and power of 80%, accounting for interim analysis and cluster size of 30 inductions per week. This was a pragmatic trial, and analysis was by intention-to-treat.

RESULTS

From January 1, 2018, to May 13, 2019, 1,117 women (34 clusters) were assigned to oral misoprostol plus Foley and 1,110 women (34 clusters) to oral misoprostol alone. Demographic characteristics were similar. Vaginal delivery at the first induction occurred in 78% of the misoprostol plus Foley arm and in 77% of the misoprostol arm (relative risk [RR] 1.00; 95% CI 0.96-1.05; adjusted relative risk [aRR], 1.00; 95% CI 0.95-1.05). Clinical chorioamnionitis occurred in 18% of the misoprostol plus Foley arm and in 14% of the misoprostol arm (RR 1.30; 95% CI 1.07-1.58; aRR 1.30; 95% CI 1.08-1.56). There were no differences in neonatal outcomes.

CONCLUSION

Induction of labor in gravid women at term with intact membranes by using oral misoprostol plus Foley bulb did not result in a higher vaginal delivery rate, but it did result in more clinical chorioamnionitis compared with the use of oral misoprostol alone.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03407625.

Outpatient management of pre-induction cervical ripening

INTRODUCTION

Induction of labor is a common obstetric intervention. For women requiring cervical ripening, the current standard practice of inpatient labor induction can be long and challenging. Outpatient cervical ripening may be a safe and beneficial option for a select subset of low-risk pregnant women.

METHODS

Electronic databases were searched with specific criteria to select articles for review. The review covered literature on the safety, efficacy and acceptability of outpatient cervical ripening in the low-risk population.

DISCUSSION

Pharmacological and mechanical cervical ripening agents have been trialed in the outpatient setting. Mechanical ripening is safer than pharmacological priming, and there appears to be no disadvantage to offering outpatient catheter balloon cervical ripening to appropriately screened women who require this intervention prior to labor induction. Maternal and midwifery acceptability of outpatient care further support outpatient cervical ripening for women with low-risk pregnancies.

CONCLUSION

The balloon catheter appears to be the optimal method for outpatient cervical ripening, but further prospective studies are required to ensure safety and benefit before it can be routinely offered to low-risk women.

Prostaglandin insert dinoprostone versus trans-cervical balloon catheter for outpatient labour induction: a randomised controlled trial of feasibility (PROBIT-F)

Background

The aim was to assess the feasibility of conducting a randomised controlled trial (RCT) of induction of labour comparing use of two methods in the outpatient setting.

Methods

An open-label feasibility RCT was conducted in two UK maternity units from October 2017 to March 2019. Women aged ≥ 16 years, undergoing induction of labour (IOL) at term, with intact membranes and deemed suitable for outpatient IOL according to local guidelines were considered eligible. They were randomised to cervical ripening balloon catheter (CRB) or vaginal dinoprostone (Propess). The participants completed a questionnaire and a sub-group underwent detailed interview. Service use and cost data were collected via the Adult Service Use Schedule (AD-SUS). Women who declined to participate were requested to complete a decliners’ questionnaire.

Results

During the study period, 274 eligible women were identified. Two hundred thirty (83.9%) were approached for participation of whom 84/230 (36.5%) agreed and 146 did not. Of these, 38 were randomised to Propess (n = 20) and CRB (n = 18). Decliner data were collected for 93 women. The reasons for declining were declining IOL (n = 22), preference for inpatient IOL (n = 22) and preference for a specific method, Propess (n = 19). The intended sample size of 120 was not reached due to restrictive criteria for suitability for outpatient IOL, participant preference for Propess and shortage of research staff.

The intervention as randomised was received by 29/38 (76%) women. Spontaneous vaginal delivery was observed in 9/20 (45%) women in the dinoprostone group and 11/18 (61%) women in the CRB group. Severe maternal adverse events were recorded in one woman in each group. All babies were born with good condition and all except one (37/38, 97.4%) remained with the mother after delivery. No deaths were recorded. − 21% of women in the dinoprostone group were re-admitted prior to diagnosis of active labour compared to 12% in the CRB group.

Conclusions

A third of the approached eligible women agreed for randomisation. An RCT is not feasible in the current service context. Modifications to the eligibility criteria for outpatient IOL, better information provision and round the clock availability of research staff would be needed to reach sufficient numbers.

Trial registration

NCT03199820. Registered on June 27, 2017

Term prelabor rupture of membranes: Foley catheter versus dinoprostone as ripening agent

INTRODUCTION

Term prelabor rupture of membranes (TPROM) occurs in approximately 8 % of pregnancies. This condition regularly requires medical intervention such as induction of labor. The actual data concerning cervical ripening in case of TPROM does not favor any of the available techniques. This is the first study comparing dinoprostone versus Foley catheter for cervical ripening in TPROM.

MATERIALS AND METHODS

We conducted a retrospective before-after study. We enrolled all the patients with confirmed TPROM after 37 weeks of gestation (WG) who required cervical ripening. Women were included if they had a singleton fetus in cephalic presentation, with unfavorable cervix (Bishop ≤ 6). Patients were excluded if they had a previous uterine surgery, a multiple pregnancy, contraindication to vaginal delivery, spontaneous labor or favorable cervix (Bishop > 6). During the first period (2015), the protocol of cervical ripening involved dinoprostone (prostaglandins E2) by vaginal administration (vaginal gel or pessary). During the second period (2016-2017), the protocol of cervical ripening involved Foley catheter (FC). The primary outcome was the rate of cesarean section.

RESULTS

Two hundred and thirty-eight patients were included for the analysis: 131 in the first period (dinoprostone group) and 107 in the second period (foley catheter group). There was no significant difference between the two groups regarding the mode of delivery (cesarean section: 206 % vs 13 %, p = 016). Concerning tolerance, the were no difference in the rates of postpartum hemorrhage, maternal per-partum fever and endometrisis. Neonatal outcomes were similar between the two groups. The induction to delivery interval was lower with dinoprostone (20,3 h versus 26,0 h, p = 0001). The mean duration of labor was also significantly different (6,9 h for dinoprostone group versus 8,7 h for FC group, p = 001).

CONCLUSION

Cervical ripening in case of TPROM after 37 W G with Foley catheter seems to be a safe technique with similar outcomes to prostaglandins regarding the mode of delivery.

Do fertility treatments affect labor induction success rate? A retrospective cohort study

Purpose: To evaluate labor induction success rate by Foley catheter (FC) on patients who conceived spontaneously, as compared to those who underwent fertility treatments.Materials and methods: This retrospective cohort study included all pregnant women hospitalized at a single tertiary care center between January 2011 and May 2018 for induction of labor with FC. The study groups included patients with a singleton pregnancy who conceived after fertility treatments: controlled ovarian hyperstimulation (COH) or in vitro fertilization (IVF), while control group included patients who conceived spontaneously. Our primary outcome was the rate of cesarean deliveries. Regression analysis was conducted on the following parameters: age, gravidity, parity, the gestational week, and IVF.Results: The study groups included 59, 321, and 3159 patients who conceived following COH, IVF, or spontaneously, respectively. While 72.1% of patients who conceived spontaneously had a vaginal delivery, only 62.7% and 58% of patients who conceived by COH and IVF had successful labor induction (respectively, p < .01). Similarly, significantly higher cesarean section (CS) rates were demonstrated by patients who conceived by COH and IVF (28.8% and 30%, respectively), compared to the control group (18.7%, p < .01). Regression analysis demonstrated that although age, parity, and the gestational week were significantly related to cesarean sections, no statistically significant association was found regarding fertility treatments (p = .050).Conclusions: The possible association between fertility treatments and cesarean delivery remains an important dilemma for obstetricians and fertility experts. While unadjusted analysis demonstrated such association among patients who undergo labor induction by FC, adjusted analysis has not supported that finding. Further studies focusing on the causes of failed vaginal delivery are needed to further expand our knowledge and to improve patient consultation.

Balloon catheter use for cervical ripening in women with term pre-labor rupture of membranes: A 5-year cohort study

INTRODUCTION

To investigate the safety of balloon catheter for cervical ripening in women with term pre-labor rupture of membranes (PROM) and to compare the incidence of maternal and neonatal infections in women with PROM and women with intact membranes undergoing cervical ripening with a balloon catheter.

MATERIAL AND METHODS

This retrospective cohort study of 1923 women with term singleton pregnancy and an unfavorable cervix undergoing cervical ripening with a balloon catheter was conducted in Helsinki University Hospital between January 2014 and December 2018. For each case of PROM, two controls were assigned. The main outcome measures were the rates of maternal and neonatal infections. Statistical analyses were performed by SPSS.

RESULTS

In all, 641 (33.3%) women following PROM and 1282 (66.6%) women with intact amniotic membranes underwent labor induction. The rates of intrapartum infection (3.7% vs 7.7%; P = .001) and neonatal infection (1.7% vs 3.8%; P = .01) were not increased in women induced by balloon catheter following PROM. Intrapartum infections were associated with nulliparity (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.6-6.5), history of previous cesarean section (OR 2.8, 95% CI 1.2-6.4), extended gestational age ≥41 weeks (OR 1.9, 95% CI 1.2-3.0) and an induction to delivery interval of 48 hours or more (OR 2.0, 95% CI 1.2-3.3). The risk of neonatal infection was associated with nulliparity (OR 3.3, 95% CI 1.4-8.0), gestational age ≥41 weeks (OR 1.9, 95% CI 1.09-3.36) and induction to delivery interval of 48 hours or more (OR 3.4, 95% CI 1.9-6.0).

CONCLUSIONS

Use of balloon catheter in women with term PROM appears safe and was not associated with increased maternal or neonatal infectious morbidity.

Intracervical Foley Catheter Plus Intravaginal Misoprostol vs Intravaginal Misoprostol Alone for Cervical Ripening: A Meta-Analysis

Currently, there is no meta-analysis comparing intravaginal misoprostol plus intracervical Foley catheter versus intravaginal misoprostol alone for term pregnancy without identifying risk factors. Therefore, the purpose of this study is to conduct a systematic review and meta-analysis of randomized control trials (RCTs) comparing concurrent intravaginal misoprostol and intracervical Foley catheter versus intravaginal misoprostol alone for cervical ripening. We systematically searched Embase, Pubmed, and Cochrane Collaboration databases for randomized controlled trials (RCTs) comparing intracervical Foley catheter plus intravaginal misoprostol and intravaginal misoprostol alone using the search terms "Foley", "misoprostol", "cervical ripening", and "induction" up to 29 January 2019. Data were extracted and analyzed by two independent reviewers including study characteristics, induction time, cesarean section (C/S), clinical suspicion of chorioamnionitis, uterine tachysystole, meconium stain, and neonatal intensive care unit (NICU) admissions. Data was pooled using random effects modeling and calculated with risk ratio (RR) and 95% confidence interval (CI). Pooled analysis from eight studies, including 1110 women, showed that labor induction using a combination of intracervical Foley catheter and intravaginal misoprostol decreased induction time by 2.71 h (95% CI -4.33 to -1.08, p = 0.001), as well as the risk of uterine tachysystole and meconium staining (RR 0.54, 95% CI 0.30-0.99 and RR 0.48, 95% CI 0.32-0.73, respectively) significantly compared to those using intravaginal misoprostol alone. However, there was no difference in C/S rate (RR 0.93, 95% CI 0.78-1.11) or clinical suspicion of chorioamnionitis rate (RR 1.22, CI 0.58-2.57) between the two groups. Labor induction with a combination of intracervical Foley catheter and intravaginal misoprostol may be a better choice based on advantages in shortening induction time and reducing the risk of uterine tachysystole and meconium staining compared to intravaginal misoprostol alone.

Intrauterine Foley catheter for 48 versus 24 hours for cervical ripening: A randomized controlled trial

OBJECTIVE

To compare the safety of keeping an intrauterine Foley catheter for 48 hours versus 24 hours for cervical ripening.

METHODS

A randomized controlled trial was conducted at the De Soysa Hospital for Women, Sri Lanka from April 1 to December 31, 2014 (trial registration: SLCTR/2014/006). Low-risk women with a Bishop score ≤5 at 40 weeks + 5 days of gestation were allocated to either 24-hour (n=107; Group A) or 48-hour (n=94; Group B) groups. Proportions developing spontaneous onset of labor (SOL), neonatal status, pre- and post-procedure C-reactive protein (CRP), cervical smears, and placental histology in those who experienced SOL were compared.

RESULTS

In Group A, 35 (32.7%) experienced SOL, against 54 (57.4%) in Group B (P<0.001, odds ratio 2.78, 95% confidence interval 1.56-4.93). There was no difference in mean length of active labor (7.48 vs 7.69 hours), cesarean delivery (16% vs 14%), bacterial vaginosis rates in post-induction cervical smear (10.3% vs 6.7%), mean CRP increase (4.08 vs 3.91 IU), evidence of chorioamnionitis (5.7% vs 11.1%), mean 1 and 5-minute Apgars, number of neonates with pyrexia (8.4 vs 8.5%), and admission to the Special Care Baby Unit (15% vs 12.8%).

CONCLUSION

Group B experienced a statistically significant increase in SOL, without increasing infectious and neonatal morbidity.

Comparing Foley Catheter to Prostaglandins for Cervical Ripening in Multiparous Women

OBJECTIVE

This study sought to test the hypothesis that among multiparous women requiring cervical ripening, mechanical ripening with a Foley catheter is more effective than prostaglandin preparations.

METHODS

This was a retrospective analysis of multiparous women with a singleton gestation who required cervical ripening in a single tertiary center from 2014 to 2019. Women who underwent cervical ripening with a Foley catheter (Foley group) were compared with women who underwent cervical ripening using a controlled-release dinoprostone vaginal insert (PGE₂-CR group) or dinoprostone vaginal gel (PGE₂-gel group). The primary outcome was the ripening-to-delivery interval.

RESULTS

A total of 229 women met the study criteria (Foley group: 95; PGE₂-CR group: 83; PGE₂-gel group: 51). Women in the Foley group had a significantly shorter ripening-to-delivery interval compared with women in the PGE₂-CR group (16.2 ± 9.2 hours vs. 27.0 ± 14.8 hours; P < 0.001) and were more likely to deliver within 12 hours (47.4% vs. 12.0%; P < 0.001; adjusted relative risk [aRR] 3.87; 95% confidence interval [CI] 2.07-7.26) and within 24 hours (78.9% vs. 49.4%; P < 0.001; aRR 1.61; 95% CI 1.26-2.06). Women in the Foley group were also less likely to require a second ripening method compared with women in the PGE₂-CR group (1.1% vs. 8.4%; P = 0.018; aRR 7.26; 95% CI 2.99-17.62). These differences were not observed when comparing the Foley and the PGE₂-gel groups. The cesarean section rate was similar among the Foley group (9.5%), PGE₂-CR group (9.6%; P = 0.970), and PGE₂-gel group (11.8%; P = 0.664).

CONCLUSION

In multiparous women requiring cervical ripening, all methods of cervical ripening have a similar success rate. However, the use of a PGE₂-CR insert is associated with a considerably longer interval to delivery compared with a Foley catheter or PGE₂ gel.

Oral misoprostol, low dose vaginal misoprostol, and vaginal dinoprostone for labor induction: Randomized controlled trial

OBJECTIVE

To compare effectiveness and safety of oral misoprostol (50 μg every four hours as needed), low dose vaginal misoprostol (25 to 50 μg every six hours as needed), and our established dinoprostone vaginal gel (one to two mg every six hours as needed) induction.

MATERIALS AND METHODS

Consenting women with a live term single cephalic fetus for indicated labor induction were randomized (3N = 511). Prior uterine surgery or non-reassuring fetal surveillance were exclusions. Concealed computer generated randomization was stratified and blocked. Newborns were assessed by a team unaware of group assignment. The primary outcome was time from induction at randomization to vaginal birth for initial parametric analysis. Sample size was based on mean difference of 240 minutes with α2 = 0.05 and power 95%. Non-parametric analysis was also pre-specified ranking cesareans as longest vaginal births.

RESULTS

Enrollment was from April 1999 to December 2000. Demographics were similar across groups. Analysis was by intent to treat, with no loss to follow up. Mean time (±SD) to vaginal birth was 1356 (±1033) minutes for oral misoprostol, 1530 (±3249) minutes for vaginal misoprostol, and 1208 (±613) minutes for vaginal dinoprostone (P = 0.46, ANOVA). Median times to vaginal birth were 1571, 1339, and 1451 minutes respectively (P = 0.46, Kruskal-Wallis). Vaginal births occurred within 24 hours in 44.9, 53.5 and 47.7% respectively (P = 0.27, χ2). There were no significant differences in Kaplan Meier survival analyses, cesareans, adverse effects, or maternal satisfaction. The newborn who met birth asphyxia criteria received vaginal misoprostol, as did. all three other newborns with cord artery pH<7.0 (P = 0.04, Fisher Exact).

CONCLUSION

There was no significant difference in effectiveness of the three groups. Profound newborn acidemia, though infrequent, occurred only with low dose vaginal misoprostol.

MEchanical DIlatation of the Cervix-- in a Scarred uterus (MEDICS): the study protocol of a randomised controlled trial comparing a single cervical catheter balloon and prostaglandin PGE2 for cervical ripening and labour induction following caesarean delivery

INTRODUCTION

Labour induction in women with a previous caesarean delivery currently uses vaginal prostaglandin E2 (PGE2), which carries the risks of uterine hyperstimulation and scar rupture. We aim to compare the efficacy of mechanical labour induction using a transcervically applied Foley catheter balloon (FCB) with PGE2 in affected women attempting trial of labour after caesarean (TOLAC).

METHODS AND ANALYSIS

This single-centre non-inferiority prospective, randomised, open, blinded-endpoint study conducted at an academic maternity unit in Singapore will recruit a total of 100 women with one previous uncomplicated caesarean section and no contraindications to vaginal delivery. Eligible consented participants with term singleton pregnancies and unfavourable cervical scores (≤5) requiring labour induction undergo stratified randomisation based on parity and are assigned either FCB (n=50) or PGE2 (n=50). Treatments are applied for up to 12 hours with serial monitoring of the mother and the fetus and serial assessment for improved cervical scores. If the cervix is still unfavourable, participants are allowed a further 12 hours' observation for cervical ripening. Active labour is initiated by amniotomy at cervical scores of ≥6. The primary outcome is the rate of change in the cervical score, and secondary outcomes include active labour within 24 hours of induction, vaginal delivery, time-to-delivery interval and uterine hyperstimulation. All analyses will be intention-to-treat. The data generated in this trial may guide a change in practice towards mechanical labour induction if this proves efficient and safer for women attempting TOLAC compared with PGE2, to improve labour management in this high-risk population.

ETHICS AND DISSEMINATION

Ethical approval is granted by the Domain Specific Review Board (Domain D) of the National Healthcare Group, Singapore. All adverse events will be reported within 24 hours of notification for assessment of causality. Data will be published and will be available for future meta-analyses.

TRIAL REGISTRATION NUMBER

NCT03471858; Pre-results.

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.

Balloon catheter vs oxytocin alone for induction of labor in women with a previous cesarean section: A randomized controlled trial

INTRODUCTION

The aim of this study was to compare the efficacy and maternal-neonatal morbidity between balloon catheter and oxytocin for induction of labor in women with a previous cesarean section and an unfavorable cervix.

MATERIAL AND METHODS

This open-label randomized controlled trial took place in seven French hospitals. Inclusion criteria were medical indication for labor induction in pregnant women, ≥37 weeks, with lower segment cesarean section, Bishop score ≤4, no pre-labor rupture of membranes, singleton fetus in cephalic presentation. Women were allocated randomly to induction with a 50-mL balloon catheter for 12 hours or a low-dose oxytocin infusion. Primary outcome was the rate of vaginal birth. Secondary outcomes were maternal and neonatal complications.

RESULTS

The study enrolled 204 women from 26 December 2010 to 31 December 2013: 101 were allocated to receive balloon catheter and 103 to oxytocin. Vaginal birth rate was 50% (n = 51) in the balloon catheter group vs 37% (n = 38) in the oxytocin group (P = 0.050). Maternal and neonatal morbidity did not differ between balloon catheter and oxytocin groups: two uterine dehiscences vs one, one vs four maternal infections, five vs two hemorrhages and 11 vs five neonatal transfers, respectively. Heterogeneity of treatment effect for vaginal delivery was observed across initial Bishop scores. Balloon catheter was more effective for low values of bishop score.

CONCLUSIONS

Balloon catheter tended to be associated with a higher probability of vaginal delivery as compared with low-dose intravenous oxytocin when used for induction of labor in women with a previous cesarean section and low Bishop score at induction.