Evaluation of a Transcervical Foley Catheter as a Source of Infection: A Systematic Review and Meta-analysis

Vaginal dinoprostone versus Foley catheter for induction of labor at term with an unfavorable cervix: an open-label randomized controlled trial

BACKGROUND

Induction of labor with mechanical methods or pharmacological agents is used in about 20-30% of all pregnant women. We specialized in comparing the effectiveness and safety of dinoprostone versus transcervical Foley catheter for induction of labor in term pregnant women with an unfavorable cervix with adequate samples.

OBJECTIVE

To compare the effectiveness and safety of dinoprostone versus transcervical Foley catheter for induction of labor in term pregnant women with an unfavorable cervix.

STUDY DESIGN

This is a parallel, open-label randomized controlled trial in two maternal centers in Shanghai, China between October 2019 and July 2022. Women with a singleton pregnancy in cephalic presentation at term and an unfavorable cervix (Bishop score < 6) scheduled for induction of labor were eligible. 1,860 women were randomly allocated to cervical ripening with either a dinoprostone vaginal insert (10mg) or a 60cc Foley catheter for up to 24 hours. The primary outcomes were vaginal delivery rate and time to vaginal delivery. Secondary outcomes included time to delivery and maternal and neonatal morbidity. Analysis was done from an intention-to-treat perspective. The trial was registered with the China trial registry (CTR2000038435).

RESULTS

The vaginal birth rates were 72.8% (677/930) vs. 69.9% (650/930) in vaginal dinoprostone and Foley catheter, respectively (aRR 1.04, 95% CI 0.98 to 1.10, risk difference: 0.03). Time to vaginal delivery was not significantly different between the two groups (sub-distribution hazard ratio 1.11, 95% CI 0.99-1.24). Vaginal dinoprostone was more likely complicated with hyperstimulation with fetal heart rate changes (5.8% vs. 2.8%, aRR 2.09, 95% CI 1.32-3.31) and placenta abruption (0.9% vs. 0.1%, aRR: 8.04, 95% CI 1.01-64.15), while Foley catheter was more likely complicated with suspected intrapartum infection (5.1% vs. 8.2 %, aRR: 0.62, 95% CI 0.44-0.88) and postpartum infection (1.4% vs. 3.7%, aRR: 0.38, 95% CI 0.20-0.72). The composite of poor neonatal outcomes was not significantly different between the two groups (4.5% vs. 3.8%, aRR 1.21, 95% CI 0.78 to 1.88), while more neonatal asphyxia occurred in the dinoprostone group (1.2% vs. 0.2%, aRR 5.39, 95% CI 1.22 to 23.92). In a subgroup analysis, vaginal dinoprostone decreased vaginal birth rate slightly in multiparous women (90.6% vs. 97.0%, aRR 0.93, 95% CI 0.88 to 0.99).

CONCLUSIONS

In term pregnant women with an unfavorable cervix, induction of labor with vaginal dinoprostone or Foley catheter has similar effectiveness. Foley catheter leads to better safety for neonates, while it may result in a higher risk of maternal infection. Furthermore, Foley catheter should be preferred in multiparous women.

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.

Combination Foley Catheter-Oxytocin versus Oxytocin Alone following Preterm Premature Rupture of Membranes

OBJECTIVE

 The benefit of mechanical ripening agents following preterm premature rupture of membranes (PPROM) has not been established. We sought to compare the time to delivery in women who received transcervical Foley catheter plus oxytocin infusion versus oxytocin infusion alone in patients with unfavorable cervices and PPROM.

STUDY DESIGN

 This is a retrospective cohort study of patients presenting with PPROM of a live, singleton gestation between 240/7 and 366/7 weeks' gestation from January 2005 to October 2018 at a single, tertiary care institution. Patients with an unfavorable cervical examination (≤2-cm dilation), no contraindication to labor and undergoing labor induction were analyzed. Time to delivery was analyzed using multivariable linear regression adjusting for cervical dilation at induction and nulliparity. Bivariate and multivariate analyses were used where appropriate.

RESULTS

 A total of 260 participants were included: 109 who received a Foley catheter and oxytocin (Foley/oxytocin) and 151 who had oxytocin alone. Demographic characteristics were similar between the two groups. Unadjusted time to delivery was significantly shorter in the oxytocin only group (Foley/oxytocin: 20.35 hours vs. oxytocin alone: 14.7 hours, p < 0.001). No differences in length of labor were detected after adjusting for cervical dilation at induction and nulliparity (p = 0.5). The unadjusted rate of cesarean delivery was higher in the combination Foley/oxytocin group (Foley/oxytocin: 16.5% vs. oxytocin alone: 7.3%, p = 0.03), but no differences were found in the adjusted analysis (p = 0.06). There were no differences in clinical chorioamnionitis rates between the two groups (Foley/oxytocin: 8.3% vs. oxytocin alone: 9.3%, p = 0.83). Furthermore, no significant differences were found in maternal and neonatal outcomes between the two groups.

CONCLUSION

 In patients with PROM, the use of a transcervical Foley catheter in addition to oxytocin is not associated with a shorter time to delivery compared with oxytocin alone.

KEY POINTS

· Transcervical Foley catheter did not shorten length of labor in PPROM.. · Transcervical Foley catheter did not increase infection risk.. · Pitocin alone can be used in PPROM population..

Applying Tension to the Transcervical Foley Balloon and Delivery Times in Term Nulliparous Women Undergoing Induction of Labor: A Randomized Controlled Trial

OBJECTIVE

To investigate the effects of applying tension to a transcervical Foley balloon on delivery time in term nulliparous patients undergoing labor induction.

METHODS

This cluster randomized clinical trial included 279 term nulliparous women presenting for labor induction with a plan for cervical ripening through transcervical Foley balloon placement. Participants were assigned to either the tension group (n=138) or the no-tension group (n=141) on the basis of randomized, weekly clusters (26 total clusters). The primary outcome measured was the time from initial Foley balloon insertion to delivery. Secondary outcomes included cesarean delivery rates, peripartum infection, and neonatal intensive care unit (NICU) admission. Our prior data suggested that delivery time in the tension group would be about 1,053 minutes. We estimated a sample size of 260 (130 per group, 26 clusters) on the basis of a 25% difference, power of 80%, and two-sided α of 0.05.

RESULTS

A total of 279 term nulliparous patients were included in the analysis. The median time from Foley placement to delivery was 1,596 minutes (range 430-3,438 minutes) for the tension group and 1,621 minutes (range 488-3,323 minutes) for the no-tension group ( P =.8); similar results were noted for time to vaginal delivery. No significant differences were observed in the secondary outcomes, including the rates of cesarean delivery (34.1% vs 29.8%, P =.7), peripartum infection, and NICU admission, between the two groups.

CONCLUSION

Applying tension to a transcervical Foley balloon in term nulliparous women undergoing labor induction did not significantly reduce delivery time or improve secondary outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT05404776.

Comparison of digital and speculum-guided methods of transcervical Foley catheter insertion in primigravida undergoing cervical ripening at term gestation: a noninferiority randomized clinical trial

BACKGROUND

Foley catheter insertion is frequently used for cervical ripening during the induction of labor. However, the insertion failure, safety, maternal side effects, complications, and satisfaction of digital compared with speculum-guided Foley catheter placement have not been evaluated in a large trial involving primigravida.

OBJECTIVE

The study aimed to compare the insertion failure rate of digital and speculum-based transcervical Foley catheter placement in primigravida. The co-primary outcome was insertion-associated pain. The secondary outcomes were the time required for successful insertion, maternal satisfaction, and maternal complications within 24 hours of Foley insertion.

STUDY DESIGN

This randomized, open-label, parallel-arm, noninferiority clinical trial was performed in a large tertiary care university hospital. Primigravida aged >18 years with term gestation (≥37 weeks) were included in this study. Additional inclusion criteria for enrollment in this study were singleton pregnancy with a cephalic presentation, intact membrane, a Bishop score of ≤5, and reassuring preinduction fetal heart rate tracing. All women planned for cervical ripening were assessed for eligibility and were randomized into digital or speculum arms. Foley catheter insertion was performed in a supine lithotomy position. Vaginal and cervical cleaning were performed before insertion. A 22-French Foley balloon catheter was guided digitally or via speculum to position the bulb at the level of the internal os using water-soluble lubricant. Insertion-associated pain was measured using a visual numeric rating scale, and maternal satisfaction was assessed using a set of questions.

RESULTS

Four hundred and sixty-nine pregnant women were assessed for eligibility, and 446 patients were enrolled and randomized. The median age of the parturients was 24 (19-40) and 24 (18-38) years, respectively. The body mass index, gestational age at randomization, the incidence of postdated pregnancy, and prerandomization Bishop scores were comparable. Insertion failure was observed in 24 (10.8%) and 17 (7.6%) women in digital and speculum arms, respectively (relative risk=1.41 [95% confidence interval, 0.78-2.55]; P=.25). Requirements of >1 attempt (5.4% vs 3.6%) followed by the change in hands (3.6% vs 2.7%) were the most common reasons for insertion failure. The median (interquartile range) visual numeric rating scale was comparable (6 [2-9] vs 5 [2-10]; P=.15). The time taken for successful insertion was similar (58 [12-241] vs 54 [10-281]; P=.30). 9.4% and 10.8% of women required additional methods of cervical ripening. More women in the speculum group (41.7% vs 33.2%; P=.06) felt a medium level of discomfort than the digital group.

CONCLUSION

Insertion failure and insertion-related pain in the digital approach were comparable to the speculum-guided approach for transcervical Foley catheter insertion in primigravida for cervical ripening. Nevertheless, maternal satisfaction was higher in the digital group because of a lesser level of discomfort.

Two different regimens of outpatient Foley catheter induction of labor in nulliparas: A randomized trial

OBJECTIVES

To evaluate expectant compared to immediate return to hospital upon outpatient Foley catheter expulsion predicated on maternal satisfaction and amniotomy-titrated oxytocin infusion to delivery interval.

METHODS

This randomized trial was conducted in a tertiary university hospital in Malaysia from September 2020 to February 2022. A total of 330 nulliparous women at term with unripe cervices (Bishop score ≤5), singleton viable fetus in cephalic presentation, reassuring preinduction fetal heart rate tracing and intact membranes who underwent planned outpatient Foley catheter induction of labor (IOL) were included. Women were randomized to expectant or immediate return to hospital if the Foley was spontaneously expelled at home before their scheduled hospital admission the following day. Primary outcomes were amniotomy-titrated oxytocin infusion to delivery interval and maternal satisfaction on the induction process (assessed by 0-10 visual numerical rating scale [VNRS]).

RESULTS

Amniotomy-titrated oxytocin infusion to delivery interval was 8.7 ± 4.1 versus 8.9 ± 3.9 h, P = 0.605 (mean difference - 0.228 95% CI: -1.1 to +0.6 h) and maternal satisfaction VNRS score was median (interquartile range) 8 (7-9) versus 8 (7-9), P = 0.782. Early return to hospital rates were 37/165 (22.4%) versus 72/165 (43.6%), RR 0.51 (95% CI: 0.37-0.72), P ≤ 0.001, Cesarean delivery rates were 80/165 (48.5%) versus 80/165 (48.5%), RR 1.00 (95% CI: 0.80-1.25), P = 1.00 and duration of hospital stay was 54.4 ± 22.9 versus 56.7 ± 22.8 h, P = 0.364 for the expectant versus immediate return groups respectively.

CONCLUSION

In outpatient Foley catheter IOL, expectant compared to immediate return to hospital following Foley dislodgement results in similarly high maternal satisfaction. The amniotomy-titrated oxytocin to delivery duration is non-inferior with expectant management.

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.

Efficacy and safety of double balloon catheter and dinoprostone for labor induction in multipara at term

PURPOSE

The aim of this study was to comparatively assess the efficacy and safety of double balloon catheter (DBC) and dinoprostone as labor-inducing agents just for multipara at term.

METHODS

A retrospective cohort study was conducted among multipara at term with a Bishop score < 6 who needed planned labor induction from January 1, 2020, to December 30, 2020 in Maternal and Child Health Hospital of Hubei province, Tongji Medical College, Huazhong University of Science and Technology. They were divided into DBC group and dinoprostone group, respectively. Baseline maternal data, maternal and neonatal outcomes were recorded for statistical analysis. Total vaginal delivery rate, rate of vaginal delivery within 24 h, rate of uterine hyperstimulation combined with abnormal fetal heart rate(FHR) were regarded as the primary outcome variables. The difference between groups was considered statistically significant when p value < 0.05.

RESULTS

A total of 202 multiparas was included for analysis (95 women in DBC group vs 107 women in dinoprostone group). There were no significant differences in total vaginal delivery rate and rate of vaginal delivery within 24 h between groups. Uterine hyperstimulation combined with abnormal FHR occurred exclusively in dinoprostone group.

CONCLUSION

DBC and dinoprostone seem to be equally effective, while, DBC seems to be safer than dinoprostone.

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.

Prevention of Early-Onset Neonatal Group B Streptococcal Disease: A Comprehensive Review of Major Guidelines

Importance

Group B Streptococcus (GBS) colonization during pregnancy is associated with significant neonatal morbidity and mortality and represents a major public health concern, often associated with poor screening and management.

Objective

The aim of this study was to review and compare the most recently published influential guidelines on the screening and management of this clinical entity during antenatal and intrapartum periods.

Evidence Acquisition

A descriptive review of guidelines from the American College of Obstetricians and Gynecologists, the Royal College of Obstetricians and Gynecologists, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, and the Society of Obstetricians and Gynecologists of Canada on the prevention of early-onset neonatal group B streptococcal disease was carried out.

Results

There is a consensus among the reviewed guidelines regarding the optimal screening specimen type, indications for intrapartum antibiotic administration such as bacteriuria during pregnancy, clinical signs of chorioamnionitis or maternal pyrexia, and history of GBS-related neonatal disease. There is also agreement on several conditions where no intervention is recommended, that is, antepartum treatment of GBS and GBS-positive women with planned cesarean delivery and intact membranes. Controversy exists regarding the optimal screening time, with the Royal College of Obstetricians and Gynecologists stating against routine screening and on management strategies related to preterm labor and preterm prelabor rupture of membranes.

Conclusions

The development of consistent international practice protocols for the timely screening of GBS and effective management of this clinical entity both during pregnancy and the intrapartum period seems of paramount importance to safely guide clinical practice and subsequently improve neonatal outcomes.

Association between intracervical Foley balloon and clinical chorioamnionitis among patients with group B streptococcus colonization undergoing induction with standardized labor management

BACKGROUND

Intracervical Foley balloons are commonly used for cervical ripening, but there has been a historical concern regarding an increased risk of clinical chorioamnionitis with Foley balloon use in patients with group B streptococcus.

OBJECTIVE

This study aimed to determine whether intracervical Foley balloon use in patients with group B streptococcus is associated with an increased risk of clinical chorioamnionitis.

STUDY DESIGN

This was a secondary analysis of a randomized controlled trial Mechanical and Pharmacologic Methods of Labor Induction: A Randomized Controlled Trial that compared cervical ripening agents within a standardized labor protocol. Foley balloon (alone, with oxytocin, or with misoprostol) was compared with misoprostol only to evaluate the primary outcome of clinical chorioamnionitis, defined based on the American College of Obstetricians and Gynecologists guidelines. Patients with a term, singleton pregnancy with intact membranes and an unfavorable cervix (Bishop score of ≤6 and dilation ≤2 cm) and a known group B streptococcus status were included. The secondary outcomes included a composite postpartum maternal infectious outcome consisting of any occurrence of endometritis, wound infection, postpartum urinary tract infection, or maternal sepsis; additional secondary outcomes included neonatal outcomes. Binomial regression with robust error variance was used to evaluate whether group B streptococcus status modified the relationship between Foley balloon use and clinical chorioamnionitis and to adjust for confounders.

RESULTS

A total of 491 patients were enrolled in the original trial. Of these patients, 467 had a known group B streptococcus status and underwent cervical ripening: 182 (39.0%) had group B streptococcus, and 285 (61.0%) did not have group B streptococcus. Moreover, 73.0% of patients received a Foley balloon, and 27.0% of patients did not receive a Foley balloon. There was no difference in the demographic or clinical characteristics between groups. The overall rate of clinical chorioamnionitis was 12.2%, with no difference between those with and without a Foley balloon (12.6% vs 11.1%, respectively; P=.66). Group B streptococcus status did not modify the association between Foley balloon use and clinical chorioamnionitis (relative risk, 0.93; 95% confidence interval, 0.50-1.72). This remained unchanged after adjusting for gestational age (adjusted relative risk, 0.87; 95% confidence interval, 0.45-1.67). Furthermore, other maternal and neonatal outcomes were similar between groups.

CONCLUSION

In this secondary analysis of a large randomized trial using a standardized labor protocol, there was no increased risk of infectious morbidity with Foley balloon use in patients overall and in patients with group B streptococcus. Our findings support that a Foley balloon can be safely used for cervical ripening in patients with group B streptococcus colonization.

Foley catheter (80 vs 60 mL) and misoprostol for labor induction in nulliparous women: a randomized controlled trial

BACKGROUND

Induction of labor is a common intervention in obstetrics worldwide. Foley catheter is a commonly used mechanical method for labor induction in nulliparous women with an unfavorable cervix at term. We hypothesize that a higher volume of Foley catheter (80 mL vs 60 mL) will shorten the induction-delivery interval for labor induction in nulliparous women at term with an unfavorable cervix with simultaneous use of vaginal misoprostol.

OBJECTIVE

This study aimed to evaluate the effect of transcervical Foley catheter (80 mL vs 60 mL) with simultaneous use of vaginal misoprostol on the induction-delivery interval in nulliparous women at term with an unfavorable cervix for induction of labor.

STUDY DESIGN

In this double-blind, single-center, randomized controlled trial, nulliparous women with a term singleton gestation with unfavorable cervix were randomized to either group 1 (Foley catheter [80 mL] simultaneously with vaginal misoprostol 25 µg every 4h) or group 2 (Foley catheter [60 mL] with vaginal misoprostol 25 µg every 4h). The primary outcome was induction-delivery interval. Secondary outcomes were duration of the latent phase of labor, number of doses of vaginal misoprostol required, mode of delivery, as well as maternal and neonatal morbidity. Analyses were based on the intention-to-treat method. A sample size of 100 women per group (N=200) was selected.

RESULTS

Between September 2021 to September 2022, 200 nulliparous women at term with an unfavorable cervix were randomized to labor induction with either FC (80 mL vs 60 mL) and vaginal misoprostol. Induction delivery interval (in minutes) was statistically significantly shorter in Foley catheter (80 mL) (median [interquartile range], 604 [524-719] vs 846 [596-990]; [P<.001]). Median time to labor onset (in minutes) (240 [120-300] vs 360 [180-600]; P<.001) was also shorter in group 1 (80 mL). The number of doses of misoprostol required for labor induction was statistically significantly less than with 80 mL (mean±standard deviation, 1.4±0.7 vs 2.4±1.3; P<.001). There was no statistically significant difference in the mode of delivery (vaginal delivery: 69 vs 80; odds ratio, 0.55 [1.1-0.3]; P=.104 and cesarean delivery: 29 vs 17; odds ratio, 0.99 [0.9-1.1]; P=.063, respectively). The relative risk of delivery within 12 hours with 80 mL was 2.4 [95% confidence interval, 1.68-3.43], P<.001. Maternal and neonatal morbidity were similar across the 2 groups.

CONCLUSION

FC (80 mL) simultaneously with vaginal misoprostol significantly shortens the induction-delivery interval (P<.001) in nulliparous women at term with an unfavorable cervix, as compared with Foley catheter 60 mL and vaginal misoprostol.

Application of intrauterine balloons in cervical ripening

INTRODUCTION

At present, the double balloon represented by the COOK Cervix Ripening Balloon and the single balloon represented by the Foley catheter are the commonly used intrauterine balloons. The application of intrauterine balloons in cervical ripening has evolved over 100 years. Although intrauterine balloons have been widely used in cervical ripening, the effect of labor induction in clinical practice does not satisfy all clinicians, especially patients with poor cervical maturity.

AREAS COVERED

The research in this review is about intrauterine balloons and cervical ripening.

EXPERT OPINION

This article reviews the historical evolution and different application methods of intrauterine balloons in cervical ripening, such as application range, placement method and placement duration of intrauterine balloons, volume and temperature of the solution fillings, and whether to apply traction to the catheter. We aim to better understand the principle of intrauterine balloons in cervical ripening and make this method more effective.

Mechanical methods for induction of labour

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

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

Labor induction with combined low-dose oral misoprostol and Foley catheter vs oral misoprostol alone at term gestation—a randomized study

BACKGROUND

The ideal method for induction of labor is still not clearly defined. Recent reports in literature have shown that oral administration of low-dose misoprostol is as effective as vaginal administration for induction of labor. The use of vaginal misoprostol in combination with Foley catheter has been shown to shorten the period of induction. However, there are limited reports on the use of oral misoprostol in combination with Foley catheter. Given the convenience of oral administration, improved compliance relative to other methods is probable. This study proposed that the combination of oral misoprostol and Foley catheter would be a better means of inducing labor.

OBJECTIVE

To compare the efficacy of combined low-dose oral misoprostol and Foley catheter with oral misoprostol alone for induction of labor at term gestation. The efficacy was compared in terms of the induction-to-delivery interval and the number of women delivering vaginally within 24 hours. The second objective was to document adverse events, if any, of the 2 protocols.

STUDY DESIGN

The study was conducted at a tertiary care center and included 200 patients with indication for induction, randomly allotted to either of the 2 groups: group A (a combination of Foley catheter and 25-µg misoprostol every 2 hours orally) and group B (only 25-µg misoprostol every 2 hours orally), using computer-generated random number sequence. The obstetrical and neonatal outcomes were recorded and compared between the 2 groups. Quantitative variables were compared using unpaired and paired t-tests within the groups across follow-ups.

RESULTS

Group A had significantly shorter mean induction-to-active-labor interval (10.67±1.75 vs 16.28±1.69 hours), mean induction-to-full-dilation interval (11.49 vs 19.00 hours), and mean induction-to-delivery interval (16.85 vs 21.90 hours). The proportion of women delivering vaginally within 24 hours was higher in group A (76 vs 57 women). In comparing maternal side effects, the only significant difference between the 2 groups was found in postpartum hemorrhage. A 5-minute Apgar score <7 was significantly more frequent in group B.

CONCLUSION

The combination of oral misoprostol with transcervical Foley catheter reduced the induction-to-delivery interval significantly (P=.001). In addition, the proportion of women delivering vaginally within 24 hours was significantly higher. Hence, the use of oral misoprostol with Foley catheter for induction of labor would be beneficial for patients.

Evaluating misoprostol and mechanical methods for induction of labour: Scientific Impact Paper No. 68 April 2022

Increasingly, births around the world are started artificially using medications or other methods. This process is known as induction of labour. As it becomes more common, methods are needed to meet the different clinical needs and birth preferences of women. Induction of labour typically includes a combination of the medication dinoprostone inserted into the vagina, artificial rupture of membranes ('releasing the waters'), and synthetic oxytocin (hormone given via a drip). This paper reviews some of the methods less commonly used for induction in the UK, namely a drug called misoprostol, which can be given orally or vaginally, and 'mechanical' methods, where labour is started by stretching the cervix (neck of the womb), most commonly with a soft silicone tube with a balloon near the tip, filled with water. Low-dose oral misoprostol tablets are now commercially available in the UK. Other methods for labour induction are not reviewed in detail in this paper. The evidence suggests mechanical induction of labour (using a balloon catheter) and misoprostol are both at least as safe and effective as using the standard drug, dinoprostone. There is evidence to suggest a balloon catheter may reduce the chance of serious negative outcomes for babies when compared with dinoprostone, and that giving low-dose oral misoprostol results in fewer caesarean births. Where possible and after informed consent, the method of induction of labour should be personalised to suit the individual woman, her clinical condition, and the setting in which she is giving birth. Local contexts and resources also need to be taken into account. To date, research into women's perspectives and experiences of induction of labour have been significantly lacking.

Mechanical Methods for the Induction of Labour After Previous Caesarean Section – An Updated, Evidence-based Review

There are currently no up-to-date evidence-based recommendations on the preferred method to induce labour after previous Caesarean section, especially for patients with unripe cervix, as randomised controlled studies are lacking. Intravenous oxytocin and misoprostol are contraindicated in these women because of the high risk of uterine rupture. In women with ripe cervix (Bishop Score > 6), intravenous administration of oxytocin is an effective procedure with comparable rates of uterine rupture to those with spontaneous onset of labour. Vaginal prostaglandin E ₂ (PGE ₂ ) and mechanical methods (balloon catheters, hygroscopic cervical dilators) are effective methods to induce labour in pregnant women with unripe cervix and previous Caesarean section. According to current guidelines, the administration of PGE ₂ is associated with a higher rate of uterine rupture compared to balloon catheters. Balloon catheters are therefore a suitable alternative to PGE ₂ to induce labour after previous Caesarean section, even though this is an off-label use. In addition to two meta-analyses published in 2016, 12 mostly retrospective cohort/observational studies with low to moderate levels of evidence have been published on mechanical methods of cervical ripening after previous Caesarean section. But because of the significant heterogeneity of the studies, substantial differences in study design, and insufficient numbers of pregnant women included in the studies, it is not possible to make any evidence-based recommendations based on these studies. According to a recent meta-analysis, the average rate using balloon catheters is approximately 53% and the average rate after spontaneous onset of labour is 72%. The uterine rupture rate was 0.2–0.9% for vaginal PGE ₂ and 0.56–0.94% for balloon catheters and is therefore comparable to the uterine rupture rate associated with spontaneous onset of labour. According to the product informations, hygroscopic cervical dilators (Dilapan-S) are currently the only method which is not contraindicated for cervical ripening/induction of labour in women with previous Caesarean section, although data are insufficient. Well-designed, randomised, controlled studies with sufficient case numbers comparing balloon catheters and hygroscopic cervical dilators with mechanical methods and vaginal prostaglandin E ₂ /oral misoprostol are therefore necessary to allow proper decision-making.

Mifepristone versus balloon catheter for labor induction: a cohort study

OBJECTIVE

to compare trans-cervical balloon catheter with oral administration of mifepristone for induction of labor.

METHODS

Retrospective cohort study including a total of 325 patients; labor was induced with Foley catheter (group I, n = 220) or mifepristone (group II, n = 105). We selected patients with cervical ripening ≤5 cm according to Bishop score (n = 208) and divided into 2 subgroups depending on the parity: group I, primiparous with a Bishop score of ≤5, n = 70 - I (1, ≤5); group I, multiparous with a Bishop score of ≤5, n = 44 - I (2,≤5); group II, primiparous with a Bishop score of ≤5, n = 65 - II (1, ≤5); group II, multiparous with a Bishop score of ≤5, n = 29 - II (2, ≤5). Frequencies and percentages were presented using analysis of variance.

RESULTS

Vaginal delivery occurred more frequently in patients induced by mifepristone (76.5%) vs. Foley catheter (74.5%). However, vaginal delivery within 24 h from the onset of induction occurred in the majority of patients in the Foley catheter groups: 39 (55.7%) and 28 (63.6%) versus 15 (23.1%) and 6 (20.7%) in groups induced with mifepristone. The frequency of cesarean section in the primiparas induced using a Foley catheter was 14%, with the use of mifepristone 21%. However, all multiparas induced with mifepristone delivered vaginally, in contrast to 30.7% of multiparas with the placement of a Foley catheter which required a cesarean delivery.

CONCLUSION

Comparison of the effectiveness of induction of labor with the use of mifepristone and an intracervical balloon Foley catheter showed that both of these methods are successful, with more deliveries within the first 24 hrs achieved by using Foley catheter. The results of this study support the postulate that the success of an induction is largely dependent on the degree of cervical ripening and parity.

Comparison of the effectiveness and pregnancy outcomes of labor induction with dinoprostone or single-balloon catheter in term nulliparous women with borderline oligohydramnios

Backgrounds:

At present, there is no consensus on the induction methods in term pregnancy with borderline oligohydramnios. This study aimed to compare the effectiveness and pregnancy outcomes of labor induction with dinoprostone or single-balloon catheter (SBC) in term nulliparous women with borderline oligohydramnios.

Methods:

We conducted a retrospective cohort study from January 2016 to November 2018. During the study period, a total of 244 cases were enrolled. Of these, 103 cases were selected for induction using dinoprostone and 141 cases were selected for induction with SBC. The pregnancy outcomes between the two groups were compared. Primary outcomes were successful vaginal delivery rates. Secondary outcomes were maternal and neonatal adverse events. Multivariate logistic regression was used to assess the risk factors for vaginal delivery failure in the two groups.

Results:

The successful vaginal delivery rates were similar between the dinoprostone group and the SBC group (64.1% [66/103] vs. 59.6% [84/141], P = 0.475), even after adjustment for potential confounding factors (adjusted odds ratio [aOR]: 1.07, 95% confidence interval [CI]: 0.57–2.00, P = 0.835). The incidence of intra-amniotic infection was lower in the dinoprostone group than in the SBC group (1.9% [2/103] vs. 7.8% [11/141], P < 0.001), but the presence of non-reassuring fetal heart rate was higher in the dinoprostone group than in the SBC group (12.6% [13/103] vs. 0.7% [1/141], P < 0.001). Multivariate logistic regression showed that nuchal cord was a risk factor for vaginal delivery failure after induction with dinoprostone (aOR: 6.71, 95% CI: 1.96–22.95). There were three factors related to vaginal delivery failure after induction with SBC, namely gestational age (aOR: 1.51, 95% CI: 1.07–2.14), body mass index (BMI) >30 kg/m² (aOR: 2.98, 95% CI: 1.10–8.02), and fetal weight >3500 g (aOR: 2.49, 95% CI: 1.12–5.50).

Conclusions:

Term nulliparous women with borderline oligohydramnios have similar successful vaginal delivery rates after induction with dinoprostone or SBC, with their advantages and disadvantages. In women with nuchal cord, the risk of vaginal delivery failure is increased if dinoprostone is used in the induction of labor. BMI >30 kg/m², large gestational age, and estimated fetal weight >3500 g are risk factors for vaginal delivery failure after induction with SBC.

Outpatient Foley catheter induction protocol provides clinical and cost benefits

BACKGROUND

Obstetric induction procedures are expensive, and little is known of the specific difference in cost between inpatient and outpatient protocols for these procedures.

OBJECTIVE

The objective of this study was to examine the difference in health care costs, maternal and neonatal morbidity, and cesarean birth rates for inpatient versus outpatient Foley induction protocols.

MATERIAL AND METHODS

We conducted a retrospective study using deliveries from 2013 to 2015 that received an outpatient or inpatient Foley catheter induction. Inductions were matched by race, parity, and maternal age. We used univariate and multivariate logistic regression to test the association between type of induction, length of stay, and cost. Maternal and neonatal factors and cesarean rates were also considered.

RESULTS

A total of 163 outpatient Foley inductions were matched 1:1 to inpatient inductions. Outpatient inductions were more likely to have a shorter length of hospitalization from admission to discharge (a 7.17-hour difference, 95% CI, 71.00, 77.59) and lower costs of hospitalization ($408 per patient, 95% CI, 4305, 4714). In the univariate analysis, there was no difference in rate of cesarean birth (OR 0.95, 95% CI, 0.61, 1.48). However, in the multivariate analysis, there was a decreased rate of cesarean for outpatient inductions (OR 0.5, 95% CI, 0.26, 0.97).

CONCLUSIONS

Outpatient Foley catheter induction appears to be a safe, cost-effective method for induction of labor. Generating protocols allowing patients to receive quality care in an outpatient setting is increasingly important in current health care environments.

Outpatient vs inpatient Foley catheter induction of labor in multiparas with unripe cervixes: A randomized trial

INTRODUCTION

Multiparous labor inductions are typically successful, and the process can be rapid, starting from a ripened cervix with a predictable response to amniotomy and oxytocin infusion. Outpatient Foley catheter labor induction in multiparas with unripe cervixes is a feasible option as the mechanical process of ripening is usually without significant uterine contractions and well tolerated. Labor contractions can be initiated by amniotomy and titrated oxytocin infusion in the hospital for well-timed births during working hours as night birth are associated with adverse events. We sought to evaluate outpatient compared with inpatient Foley catheter induction of labor in multiparas for births during working hours and maternal satisfaction.

MATERIAL AND METHODS

A randomized trial was conducted in the University of Malaya Medical Center. A total of 163 term multiparas (no dropouts) with unripe cervixes (Bishop score ≤5) scheduled for labor induction were randomized to outpatient or inpatient Foley catheter. Primary outcomes were delivery during "working hours" 08:00-18:00 h and maternal satisfaction on allocated care (assessed by 11-point visual numerical rating score 0-10, with higher score indicating more satisfied).

CLINICAL TRIAL REGISTRATION

ISRCTN13534944.

RESULTS

Comparing outpatient and inpatient arms, delivery during working hours were 54/82 (65.9%) vs. 48/81 (59.3%) (relative risk 1.1, 95% CI 0.9-1.4, p = 0.421) and median maternal satisfaction visual numerical rating score was 9 (interquartile range 9-9) vs. 9 (interquartile range 8-9, p = 0.134), repectively. Duration of hospital stay and membrane rupture to delivery interval were significantly shorter in the outpatient arm: 35.8 ± 20.2 vs. 45.2 ± 16.2 h (p = 0.001) and 4.1 ± 2.9 vs. 5.3 ± 3.6 h (p = 0.020), respectively. Other maternal and neonatal secondary outcomes were not significantly different.

CONCLUSIONS

The trial failed to demonstrate the anticipated increase in births during working hours with outpatient compared with inpatient induction of labor with Foley catheter in parous women with an unripe cervix. Hospital stay and membrane rupture to delivery interval were significantly shortened in the outpatient group. The rate of maternal satisfaction was high in both groups and no significant differences were found.

Review of Evidence-Based Methods for Successful Labor Induction

Induction of labor is increasingly a common component of the intrapartum care. Knowledge of the current evidence on methods of labor induction is an essential component of shared decision-making to determine which induction method meets an individual's health needs and personal preferences. This article provides a review of the current research evidence on labor induction methods, including cervical ripening techniques, and contraction stimulation techniques. Current evidence about expected duration of labor following induction, use of the Bishop score to guide induction, and guidance on the use of combination methods for labor induction are reviewed.

Vaginal streptococcus B colonization is not associated with increased infectious morbidity in labor induction

INTRODUCTION

Labor induction rates are increasing and, in Finland today, one of three labors is induced. Group B streptococcus (GBS) is a bacterium found in 10%-30% of pregnant women and it can be transmitted to the neonate during vaginal delivery. Although GBS is rarely harmful in the general population, it is the leading cause of severe neonatal infections such as sepsis, pneumonia, and meningitis. In addition, GBS can cause maternal morbidity. Labor induction in GBS-positive women has not yet been investigated but concerns of infectious morbidity associated with balloon catheters have been raised.

MATERIAL AND METHODS

A historical cohort study of 1959 women undergoing labor induction by balloon catheter in Helsinki University Hospital, Finland, between January 1, 2014 and December 31, 2017. Women with viable singleton term pregnancy in cephalic presentation, unfavorable cervix (Bishop score <6), and intact amniotic membranes were included. GBS was screened by rapid qualitative in vitro test (XPert^® GBS) from vaginal and perineal culture upon admission for labor induction. All women testing positive received prophylactic antibiotics.

RESULTS

Of the women, 469 (23.9%) were GBS-positive. The rate of maternal intrapartum infection was 7.4%, being lower in the GBS-positive group compared with the GBS-negative group (4.7% vs 8.3%; p = 0.01). The rate of maternal postpartum infection was 3.9%, and the rate of neonatal infection was 3.3%, both being similar between the groups. Also, no difference in the rates of other adverse neonatal outcomes was seen. No GBS sepses occurred in the study. In multivariable logistic regression, rupture of membranes to delivery interval ≥12 hours was associated with maternal intrapartum and postpartum infection, as well as neonatal infection. Other risk factors for maternal intrapartum infection were GBS-negativity, nulliparity, prolonged pregnancy (≥41 weeks), and Bishop score <3 at the start of induction. Cesarean section was associated with postpartum endometritis, while nulliparity, gestational diabetes, and maternal intrapartum infection were associated with neonatal infection.

CONCLUSIONS

Regarding maternal and neonatal infectious morbidity, labor induction with balloon catheter appears safe in women colonized with GBS when prophylactic antibiotics are administered at the onset of labor or at membrane rupture.

Foley Bulb Insertion by Blind Placement Compared With Direct Visualization: A Randomized Controlled Trial

OBJECTIVE

To test the hypothesis that digital placement of a balloon catheter is not inferior to the speculum method in terms of rate of maternal infection.

METHODS

In an open-label noninferiority randomized trial, pregnant women who were undergoing induction of labor with unfavorable cervix (less than 3 cm dilated and less than 60% effaced) were randomly assigned to balloon catheter that was placed either digitally or using a sterile speculum. The primary outcome was a composite of maternal infection, defined by occurrence of fever (temperature 38°C or higher), chorioamnionitis, or endometritis (diagnoses were made by the managing obstetric physician or midwife). Prespecified secondary outcomes included outcomes in the primary composite, cesarean delivery rates, and maternal and neonatal outcomes. A patient satisfaction survey was also obtained. On the basis of a noninferiority margin of 10% and an expected primary outcome frequency of 10%, a sample size of 372 women was needed (90% power to confirm noninferiority with 90% protocol adherence).

RESULTS

From February 2018 through February 2019, 372 women were randomized (185 digital placement, 187 sterile speculum). Baseline characteristics were similar between groups. The composite maternal infection rate was not different between groups (digital placement arm: 15.7% vs speculum arm: 12.8%), with an absolute difference with respect to the sterile speculum arm of 2.8% (95% CI -4.3 to 9.9%), indicating noninferiority for the prespecified margin. Secondary outcomes were not different between groups, except for a higher need for a second balloon catheter in the sterile speculum arm. Maternal and neonatal adverse events were not different between groups. Irrespective of method of placement, women were equally satisfied with the explanation of the method before placement, anxiety regarding the procedure, and pain during placement. More women in the sterile speculum group would choose the digital placement method for the subsequent pregnancy (37.6% vs 25.7%; P=.02.).

CONCLUSION

Digital placement of a balloon catheter for preinduction cervical ripening is noninferior to the sterile speculum method, in terms of maternal infection. Women in the sterile speculum group more frequently required a second round of the mechanical dilator. The blind digital approach is a reasonable option for balloon placement for cervical ripening.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03450408.

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 patients' 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.

Outpatient Foley Catheter for Induction of Labor in Nulliparous Women: A Randomized Controlled Trial

OBJECTIVE

To assess whether outpatient cervical ripening with a transcervical Foley catheter in nulliparous women undergoing elective labor induction shortens the time from admission to delivery.

METHODS

We performed a randomized controlled trial of patients with singleton pregnancies undergoing elective labor induction at 39 weeks of gestation or more with a modified Bishop score less than 5. Women were randomized 1:1 to outpatient or inpatient transcervical Foley. In the outpatient group, the Foley was inserted the day before admission for scheduled induction; insertion was performed at scheduled admission in the inpatient group. The primary outcome was duration of time from admission to the labor and delivery unit to delivery. With 80% power and a two-sided α of 0.05, a sample size of 126 was estimated to detect at least a 5-hour mean difference in time from admission to delivery between groups from a baseline duration of 19±10 hours.

RESULTS

From May 2018 to October 2019, 126 women were randomized, 63 in each group. Baseline characteristics were balanced between groups, except that body mass index (31±5.4 vs 34±7.5, P=.01) and group B streptococcus colonization (31% vs 54%, P=.01) were lower in the outpatient group. The time from admission to delivery was shorter in the outpatient group (17.4±7.4 vs 21.7±9.1 hours, P<.01, mean difference 4.3 hours, 95% CI 1.3-7.2). Admissions before scheduled induction were higher in the outpatient group (22% vs 5%, relative risk [RR] 4.7, 95% CI 1.4-15.4, P<.01), as was median modified Bishop score on admission (3 vs 1, P<.01). Cesarean delivery (24% vs 32%, RR 0.8, 95% CI 0.4-1.3, P=.32) and chorioamnionitis (22% vs 13%, RR 1.8, 95% CI 0.8-3.9, P=.16) were not significantly different between groups.

CONCLUSION

In nulliparous patients undergoing elective labor induction at term, outpatient cervical ripening with a transcervical Foley catheter reduced the time from admission to delivery.

CLINCAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03472937.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

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.

Evidence-based labor management: induction of labor (part 2)

Induction of labor is indicated for many obstetrical, maternal, and fetal indications. Induction can be offered for pregnancy at 39 weeks' gestation. No prediction method is considered sensitive or specific enough to determine the incidence of cesarean delivery after induction. A combination of 60- to 80-mL single-balloon Foley catheter for 12 hours and either 25-μg oral misoprostol initially, followed by 25 μg every 2-4 hours, or 50 μg every 4-6 hours (if no more than 3 contractions per 10 minutes or previous uterine surgery), or oxytocin infusion should be recommended for induction of labor. Adding membrane stripping at the beginning of induction should be considered. Once 5-6 cm of cervical dilation is achieved during the induction of labor, consideration can be given to discontinue oxytocin infusion if in use at that time and adequate contractions are present. Induction with oxytocin immediately (as soon as feasible) or up to 12 hours of term prelabor rupture of membranes if labor is not evident is recommended. Outpatient Foley ripening can be considered for low-risk women. Cesarean delivery should not be performed before 15 hours of oxytocin infusion and amniotomy if feasible and ideally after 18-24 hours of oxytocin infusion.

Can we induce labor by mechanical methods following preterm premature rupture of membranes?

OBJECTIVE

To evaluate the use of the intracervical balloon compared with locally applied prostaglandins for cervical ripening for induction in patients with preterm premature rupture of membranes.

METHODS

Monocentric, retrospective (from 2002 to 2017) observational cohort study of singleton pregnancies complicated by preterm premature rupture of membranes and induced between 34 and 37 weeks. The primary outcome measure was balloon catheter efficiency evaluated by Cesarean section rate. Secondary outcomes were : interval from induction to delivery, labor duration, oxytocin use, intrauterine infection rate, maternal complications (i.e., postpartum hemorrhage and endometritis), and neonatal complications.

RESULTS

60 patients had cervical ripening with prostaglandins alone and 58 had balloon catheter. Demographic characteristics were similar between the groups, except for induction term and neonatal weight. There was not a significant difference in occurrence of Cesarean section rate (p = 0.14). Nor were there significant differences in time from induction to birth (p = 0.32) or in intrauterine infection rate (p = 0.95). Labor duration was shorter (p = 0.006) and total oxytocin dose lower (p = 0.005) in patients induced by prostaglandins alone. Concerning neonatal outcomes, there were more transfers to intensive care (p = 0.008) and more respiratory distress (p = 0.005) among newborns induced by prostaglandins.

CONCLUSION

Compared with locally applied prostaglandins, balloon catheter induction is not associated with an increase of Cesarean section rate in patients with preterm premature rupture of membranes.

Induction of labor in continuing pregnancies

This chapter aims to provide an evidence-based approach to cervical-ripening methods and induction of labor in high-, middle-, and low-income countries. We will review the epidemiology of induction and will also review pharmacological and mechanical methods of cervical-ripening as well as oxytocin for induction. Lastly, we will review current guidelines of when to determine an induction to be failed.

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.

Cervical ripening: Why we do what we do

More than 20% of pregnant women have their labor induced and at least half of them will require cervical ripening due to an unfavorable starting cervical exam. The use of cervical ripening methods has been shown to decrease the risk of cesarean delivery when compared to initiating an induction with oxytocin in women with an unfavorable cervix. However, among the different cervical ripening methods themselves, while there may be differences in time to delivery and differences in the safety profile of different cervical ripening methods, there is no clear evidence that any one cervical ripening method reduces the risk of cesarean compared to another method. The objectives of this manuscript are to discuss the pathophysiology of cervical ripening including the biochemical processes that lead to cervical ripening; to review the different methods of cervical ripening including both mechanical and pharmacologic methods, and to evaluate the evidence and efficacy for different doses, routes, and techniques employed when using various cervical ripening methods.

Predictors of vaginal delivery after cervical ripening using a synthetic osmotic dilator

OBJECTIVE

To evaluate the determinants of vaginal delivery and safety in women undergoing cervical ripening with a synthetic osmotic dilator (Dilapan-S) prior to induction of labor.

METHODS

We conducted a secondary analysis of an international multicenter prospective observational study of Dilapan-S for cervical ripening in pregnancies greater than 32 weeks. Data were obtained in a standardized fashion and entered into a centralized electronic data capture system. The association between Bishop score and vaginal delivery was further evaluated with a multivariate receiver-operating characteristic (ROC) curve analysis. A Wilcoxon rank test and multivariable logistic regression were used for statistical analysis (significance: P < .05).

RESULTS

Between May 2015 and July 2016, 444 pregnant women were included. Three hundred ten (70 %) delivered vaginally. Compared to patients who underwent cesarean delivery, those who delivered vaginally were more likely to have a history of prior vaginal delivery. Vaginal delivery rates were significantly correlated with Bishop scores of pre and post Dilapan-S and difference. After adjusting for age, BMI, number of dilators, cervical ripening time, and gestational age, both prior vaginal delivery and post-Dilapan-S Bishop scores were strong predictors of vaginal delivery (estimate coefficient: 0.1275 ± 0.03 P = .0002; 0.049 ± 0.01 P = .0001; respectively). Aggregate ROC accounting for these variables further supported these findings (AUC = 0.734). The lower confidence interval limit of vaginal delivery rates was above 50 % when post-Dilapan-S Bishop scores were ≥ 5. Cox regression analyses demonstrated that the duration of labor was significant shorter in women that had vaginal delivery.

CONCLUSION

Bishop scores after cervical ripening with Dilapan-S are good predictors of vaginal delivery. Bishop scores < 5 post Dilapan-S may warrant further cervical ripening. Further level 1 trials are needed to compare osmotic dilators to other ripening methods.

Induction of labour at 41 weeks versus expectant management and induction of labour at 42 weeks (SWEdish Post-term Induction Study, SWEPIS): multicentre, open label, randomised, superiority trial

OBJECTIVE

To evaluate if induction of labour at 41 weeks improves perinatal and maternal outcomes in women with a low risk pregnancy compared with expectant management and induction of labour at 42 weeks.

DESIGN

Multicentre, open label, randomised controlled superiority trial.

SETTING

14 hospitals in Sweden, 2016-18.

PARTICIPANTS

2760 women with a low risk uncomplicated singleton pregnancy randomised (1:1) by the Swedish Pregnancy Register. 1381 women were assigned to the induction group and 1379 were assigned to the expectant management group.

INTERVENTIONS

Induction of labour at 41 weeks and expectant management and induction of labour at 42 weeks.

MAIN OUTCOME MEASURES

The primary outcome was a composite perinatal outcome including one or more of stillbirth, neonatal mortality, Apgar score less than 7 at five minutes, pH less than 7.00 or metabolic acidosis (pH <7.05 and base deficit >12 mmol/L) in the umbilical artery, hypoxic ischaemic encephalopathy, intracranial haemorrhage, convulsions, meconium aspiration syndrome, mechanical ventilation within 72 hours, or obstetric brachial plexus injury. Primary analysis was by intention to treat.

RESULTS

The study was stopped early owing to a significantly higher rate of perinatal mortality in the expectant management group. The composite primary perinatal outcome did not differ between the groups: 2.4% (33/1381) in the induction group and 2.2% (31/1379) in the expectant management group (relative risk 1.06, 95% confidence interval 0.65 to 1.73; P=0.90). No perinatal deaths occurred in the induction group but six (five stillbirths and one early neonatal death) occurred in the expectant management group (P=0.03). The proportion of caesarean delivery, instrumental vaginal delivery, or any major maternal morbidity did not differ between the groups.

CONCLUSIONS

This study comparing induction of labour at 41 weeks with expectant management and induction at 42 weeks does not show any significant difference in the primary composite adverse perinatal outcome. However, a reduction of the secondary outcome perinatal mortality is observed without increasing adverse maternal outcomes. Although these results should be interpreted cautiously, induction of labour ought to be offered to women no later than at 41 weeks and could be one (of few) interventions that reduces the rate of stillbirths.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN26113652.

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.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 782

Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."

Induction of labour in case of premature rupture of membranes at term with an unfavourable cervix: protocol for a randomised controlled trial comparing double balloon catheter (+oxytocin) and vaginal prostaglandin (RUBAPRO) treatments

INTRODUCTION

Premature rupture of membranes (PROM) occurs at term in 8% of pregnancies. Several studies have demonstrated that the risk of chorioamnionitis and neonatal sepsis increases with duration of PROM. Decreasing the time interval between PROM and delivery is associated with lower rates of maternal infections. In case of an unfavourable cervix, the use of prostaglandin for cervical maturation demonstrates some advantages over oxytocin. The use of double balloon catheter in reduction of PROM duration has not been evaluated in the literature.

METHODS AND ANALYSIS

We are conducting a prospective, monocentric, randomised clinical trial on pregnant women with an unfavourable cervix showing PROM at term (RUBAPRO).After 12-24 hours of PROM, women are randomly assigned to one group treated with a double balloon catheter for 12 hours, with oxytocin administered after 6 hours or to the control group treated with 24 hours of vaginal prostaglandin followed by oxytocin infusion alone. Patients (n=80) are randomised at a 1:1 ratio with stratification on parity.The inclusion criteria are a Bishop score of <6, cephalic presentation at term and confirmed PROM. Women with suspected chorioamnionitis; group B streptococcus (GBS) carrier; a history of caesarean delivery or any contraindication for vaginal delivery are excluded.The time from induction to delivery is the primary outcome. Secondary outcomes were mode of delivery, maternofetal morbidity and the effect of parity on strategies for reduction of PROM duration.To sufficiently demonstrate a difference (10 hours) between groups-with a statistical power of 90% and a two-tailed α of 5%-40 patients per group will be required.

ETHICS AND DISSEMINATION

Written informed consent is required from participants.National Ethics Committee approval was obtained in August 2017. The results will be published in a peer-reviewed journal and presented at relevant conferences. Access to raw data will be available only to members of the research team.

TRIAL REGISTRATION NUMBER

NCT03310333.

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

OBJECTIVE DATA

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

STUDY

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

STUDY APPRAISAL AND SYNTHESIS METHODS

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

RESULTS

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

CONCLUSION

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

Interest of cervical ripening using double balloon catheters for labour induction in term nulliparous women

OBJECTIVE

To compare the efficiency of double balloon catheters with that of intravaginal prostaglandins alone for the labor induction of unfavourable cervices in term nulliparous women.

METHODS

50 nulliparous patients induced with a double balloon device were compared to 53 patients induced using intravaginal prostaglandins alone. The main outcome measure was labour induction failure, characterized by the absence of active labour. The secondary outcome measures were the improvement of the Bishop score, the average durations of ripening and labour induction, the average time to active labour, the need for a second cervical ripening agent, the total dose of prostaglandins used in each group, the use of oxytocins, as well as the rates of vaginal delivery, abnormal foetal heart rate during labour and perinatal maternal infection.

RESULTS

The rate of failed labour induction was of 28% in the double balloon group, against 13% in the prostaglandins group. The average durations of ripening and labour induction, as well as the time to active labour were higher in the double balloon group. The improvement of the Bishop score was significantly lower in the double balloon group.

DISCUSSION AND CONCLUSION

In our study, the use of double balloon catheters does not seem to reduce the rate of failed labour induction in nulliparous women when compared to the use of prostaglandins alone. In addition, it could lengthen the labour induction duration, although more powerful studies would be necessary not to recommend its use for nulliparous women.

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

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

Intracervical Foley catheter balloon versus dinoprostone insert for induction cervical ripening: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Successful labor induction depends on the cervical status at the time of induction. Currently, both a Foley catheter and a dinoprostone insert are used for effective cervical ripening. This study compared the efficacy and safety of the intracervical Foley catheter and dinoprostone insert for cervical ripening to achieve successful labor induction.

METHODS

PubMed, Embase, and the Cochrane Library were searched from January 2000 to February 2017 for relevant articles. Only published randomized, controlled trials comparing the dinoprostone insert with the Foley catheter were included.

RESULTS

Eight trials including 1191 women who received the intracervical Foley catheter balloon and 1199 who received the dinoprostone insert were used for this study. There was no significant difference between the 2 groups regarding the induction-to-delivery (I-D) interval in a random effect model (mean difference, 0.71 hours; 95% confidence interval [CI], -2.50 to 3.91; P = .67). The highly significant heterogeneity (I = 97%) could be explained by the subgroup analysis of the type of Foley catheter and balloon volume. There was no significant difference between the 2 methods regarding the cesarean delivery rate (relative risk, 0.91; 95% CI, 0.78-1.07; P = .24), Apgar score, or side effects, including maternal infection rate, postpartum hemorrhage, and hyperstimulation. No obvious publication bias was found.

CONCLUSIONS

According to the cesarean delivery rate, the intracervical Foley catheter balloon was as efficient as the dinoprostone insert. A moderate balloon volume (30 mL) and higher dose of dinoprostone (≥6 mg) were related to shorter I-D intervals. Additionally, there was no significant difference between the two methods regarding maternal or neonatal safety.