A prospective randomized trial comparing Foley catheter, oxytocin, and combination Foley catheter-oxytocin for labour induction with unfavourable cervix

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.

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.

Balloon catheter vs oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix: a multicenter, retrospective study

PURPOSE

To compare the rate of vaginal birth between double-balloon catheter and oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix.

MATERIALS AND METHODS

A retrospective and observational study was conducted from 2013 to 2017, at the Saint-Etienne University Hospital where women received induction with a double-balloon catheter for 12 h and at the Grenoble Alpes University Hospital where women received induction with a low-dose oxytocin infusion. Primary outcome was the rate of vaginal birth.

RESULTS

Out of 1920 women eligible for attempting a vaginal birth after one previous cesarean section, 501 had a labor induction. Among women with an unfavorable cervix, 160 received a double-balloon catheter in Saint Etienne and 152 received oxytocin alone in Grenoble. The vaginal birth rate was higher in the double-balloon catheter group (61% versus 47% in the oxytocin group). An induction of labor with oxytocin alone reduced chances of vaginal birth (aOR 0.38 CI-95% [0.22-0.66]) compared to cervical ripening with double-balloon catheter. The perinatal morbidity was similar in the two groups. There was, however, 3.9% uterine rupture in the oxytocin group versus 0.6% in the double-balloon group (p = 0.11).

CONCLUSION

For induction of labor in women with one previous cesarean section and with unfavorable cervix, cervical ripening with a double-balloon catheter increases the rate of vaginal birth without increased risk of uterine rupture.

Low-dose oxytocin as an adjunct to Foley catheter for cervical ripening in nulliparous women at MTRH, Eldoret, Kenya: A randomized controlled trial

OBJECTIVE

To investigate whether the addition of oxytocin to cervical ripening with a Foley catheter (FC) among nulliparous women shortens the time to delivery.

METHODS

In this double-blinded randomized trial conducted at Moi Teaching and Referral Hospital, 220 women were randomly assigned to FC plus low-dose oxytocin as treatment or FC plus placebo as controls in a 1:1 ratio. A modified intention-to-treat analysis was performed using SPSS v24. The protocol was approved by the institutional ethics committee and registered at www.ctr.pharmacyboardkenya.org; ECCT/19/08/02.

RESULTS

Baseline characteristics were similar. Time to delivery was shorter by 3 h in the treatment group compared with the controls (25.4 versus 28.4 h, P = 0.002). The treatment group had a 22% increased likelihood of delivery within 24 h compared with the controls (53.3% versus 43.1%, relative risk [RR] 1.22, 95% confidence interval [CI] 0.938-1.579, P = 0.135). The controls were however twice more likely to deliver by cesarean section than the treatment group (39% versus 21%, RR 2.32, 95% CI 1.16-2.73, P = 0.006). There were no significant differences in neonatal or other maternal outcomes.

CONCLUSION

FC with adjunctive oxytocin for cervical ripening in nulliparous women results in a shorter time to delivery and reduced cesarean deliveries when compared with FC alone.

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 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.

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

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

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.

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

OBJECTIVE

To assess whether outpatient cervical ripening with a transcervical Foley catheter in parous women undergoing elective induction of labor shortens the total duration of time from admission to the labor ward until delivery.

METHODS

We performed an open-label randomized controlled trial at a single academic center in parous women at 39 weeks of gestation or greater with a cervix 3 cm or less dilated, or, if 2-3 cm dilated, less than 80% effaced and reassuring fetal heart rate monitoring (defined as moderate variability with a normal baseline and absence of decelerations). Exclusions were obstetric and neonatal conditions deemed unsuitable for outpatient cervical ripening, contraindications to vaginal delivery, or conditions that required immediate hospitalization. Women were randomized in the ambulatory setting to either an outpatient transcervical catheter (with immediate placement) or inpatient transcervical catheter placement and concomitant oxytocin infusion on the labor ward. Women in the outpatient group were instructed to return to the hospital the next day or sooner if labor occurred. Induction of labor was managed per institutional protocol, and once participants were admitted, oxytocin was initiated. The primary outcome was the duration of time from labor ward admission until delivery. Based on a prior study in our institution, a total of 128 women were needed for 80% power to detect a 12-hour difference in total duration spent from labor ward admission until delivery with a two-sided α of 0.05.

RESULTS

Of 743 women screened, 129 provided consent and were randomized from May 2016 to October 2017. Baseline characteristics were balanced between groups. Outpatient cervical ripening did not significantly shorten the time from labor ward admission until delivery (12.4±7.4 vs 13.5±7.0 hours, P=.38).

CONCLUSION

Outpatient cervical ripening in parous women does not shorten the time from labor ward admission until delivery if oxytocin is initiated simultaneously with inpatient transcervical catheter placement.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02756689.

Foley catheter with simultaneous oxytocin on labor induction: a meta-analysis of randomized controlled trials

Objective: It is unclear that whether Foley catheter with simultaneous oxytocin could improve the efficacy of induction outcome. Method: To conduct a meta-analysis of randomized controlled trial (RCT) studies to evaluate the effect of Foley catheter with simultaneous oxytocin on labor induction. PubMed, Embase, and other databases were searched from their inception to July 2017. We included all RCTs comparing Foley catheter with simultaneous oxytocin (i.e. intervention group) with Foley catheter followed by oxytocin (i.e. control group) in the three kinds of women (nulliparas and multiparas/only nulliparas/only multiparas). We estimate summarized relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes, standard mean difference for continuous outcomes. Fixed- and random-effects models were used, depending on heterogeneity. Results: After application of our inclusion and exclusion criteria, six RCTs with a total of 1133 participants were identified. We found that only nulliparas had significant RR of delivery within 24 h (RR = 1.32, 95% CI: 1.12, 1.55, I² = 46.5%). Meanwhile, there was no statistically significant difference between intervention and control groups in vaginal delivery in 24 h, cesarean delivery, time to delivery, and Apgar score at 5 min less than 7. Foley catheter with simultaneous oxytocin did not increase the risk of side effects, included chorioamnionitis, postpartum hemorrhage, uterine hyperstimulation, and neonatal intensive care unit admission. Conclusion: The results seem to support the use of oxytocin to a Foley catheter at the initiation of labor induction, as it might lead to increases the rate of delivery within 24 h in nulliparas.