Progress of labor in women induced with misoprostol versus the Foley catheter

Vaginal misoprostol versus intracervical Foley catheter for cervical ripening in postdate primigravid women: a randomized clinical trial

BACKGROUND

Being one of the most common indications of labor induction, postdate pregnancy can lead to serious maternal and fetal complications. In this study we aimed to compare vaginal misoprostol with intracervical Foley catheter (FC) for cervical ripening in postdate primigravid women.

METHODS

This randomized clinical trial included 120 primigravid women aged 18-35 years with singleton,  postdate pregnancies, and Bishop score ≤ 4. Participants were randomized into two equal groups. The first group received 25 µg vaginal misoprostol and the second group had an 18 Fr FC inserted into their cervical canal. Labor induction was performed using oxytocin in both groups if progression of labor or true contractions did not occur within 6 h of the interventions. In case of nonreassuring fetal heart rate, fetal distress, placental abruption, or prolonged labor, C-section was performed.

RESULTS

The frequency of normal vaginal delivery, Cesarean section, meconium-stained amniotic fluid, and neonatal intensive care unit admission did not differ significantly between groups. Placental abruption and uterine tachysystole occurred more frequently in the misoprostol group (15.0 vs. 1.7%, P = 0.008 and 21.7 vs. 0.0%, P < 0.001, respectively). A significantly higher number of women in the FC group required oxytocin (73.3 vs. 41.7%, P < 0.001). Duration of labor was significantly higher in the FC group (P = 0.001).

CONCLUSIONS

Due to the lower rate of placental abruption and uterine tachysystole observed with FC, it appears to be superior to vaginal misoprostol for cervical ripening in postdate primigravid women; however, its longer labor duration and higher oxytocin requirement should be taken into consideration.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT20181218042033N4 . Registered 19/04/2020. Retrospectively registered, https://www.irct.ir/trial/47037.

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.

Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin

BACKGROUND

Trial of labor after cesarean (TOLAC) is a viable option for safe delivery. In some cases cervical ripening and subsequent labor induction is necessary. However, the commonly used prostaglandins are not licensed in this subgroup of patients and are associated with an increased risk of uterine rupture.

METHODS

This cohort study compares maternal and neonatal outcomes of TOLAC in women (n=82) requiring cervical ripening agents (osmotic dilator vs. prostaglandins). The initial Bishop scores (BSs) were 2 (0-5) and 3 (0-5) (osmotic dilator and prostaglandin group, respectively). In this retrospective analysis, Fisher's exact test, the Kruskal-Wallis rank sum test and Pearson's chi-squared test were utilized.

RESULTS

Vaginal birth rate (including operative delivery) was 55% (18/33) in the osmotic dilator group vs. 51% (25/49) in the dinoprostone group (P 0.886). Between 97% and 92% (32/33 and 45/49) (100%, 100%) of neonates had an Apgar score of >8 after 1 min (5, 10 min, respectively). The time between administration of the agent and onset of labor was 36 and 17.1 h (mean, Dilapan-S® group, dinoprostone group, respectively). Time from onset of labor to delivery was similar in both groups with 4.4 and 4.9 h (mean, Dilapan-S® group, dinoprostone group, respectively). Patients receiving cervical ripening with Dilapan-S® required oxytocin in 97% (32/33) of cases. Some patients presented with spontaneous onset of labor, mostly in the dinoprostone group (24/49, 49%). Amniotomy was performed in 64% and 49% (21/33 and 24/49) of cases (Dilapan-S® group and dinoprostone group, respectively).

CONCLUSIONS

This pilot study examines the application of an osmotic dilator for cervical ripening to promote vaginal delivery in women who previously delivered via cesarean section. In our experience, the osmotic dilator gives obstetricians a chance to perform induction of labor in these women.

Tension compared to no tension on a Foley transcervical catheter for cervical ripening: a randomized controlled trial

BACKGROUND

Cervical ripening of an unfavorable cervix can be achieved by placement of a transcervical catheter. Advantages of this method include both lower cost and lower risk of tachysystole than other methods. Despite widespread use with varying degrees of applied tension, an unanswered question is whether there is an advantage to placing the transcervical catheter to tension compared with placement without tension.

OBJECTIVE

The purpose of this study was to determine whether tension placed on a transcervical balloon catheter that is inserted for cervical ripening results in a faster time to delivery.

STUDY DESIGN

This was a prospective, randomized controlled trial; 140 women who underwent cervical ripening (Bishop score, ≤6) were assigned randomly to a balloon catheter with applied tension vs no tension. Tension was created when the catheter was taped to the patient's thigh and tension was reapplied in 30-minute increments. There were 67 patients in the tension group and 73 patients in the no tension group. Low-dose oxytocin (maximum, 6 mU/min) was administered after catheter placement. The primary outcome was time from catheter insertion to delivery. A secondary outcome was time from insertion to catheter expulsion. The Kolmogorov-Smirnov test was used to determine whether the data were distributed normally. Survival curves that used lifetables were constructed from time of catheter insertion to delivery and from time of catheter insertion to catheter expulsion and were compared with the use of the Wilcoxon (Gehan) Breslow statistic. A probability value of <.05 was set to denote statistical significance.

RESULTS

Baseline characteristics were similar between groups. The median time from catheter insertion to delivery was not significantly different between the tension group and the no tension group (16.2 vs 16.9 hours; P=.814). The median time from catheter insertion to expulsion, however, was significantly less in the tension group vs the no tension group (2.6 vs 4.6 hours; P<.001), respectively. Vaginal delivery within 24 hours was not significantly different between the tension and no tension groups (41/52 [79%] vs 37/52 [71%]; P=.365) nor were there significant differences in cesarean delivery rates between the tension and no tension groups (17/67 [25%] vs 27/73 [37%]; P=.139).

CONCLUSION

Application of tension did not result in faster delivery times but did result in faster times to catheter expulsion.

Cervical ripening agents in the second trimester of pregnancy in women with a scarred uterus: a systematic review and metaanalysis of observational studies

OBJECTIVE

The aim of this systematic review and metaanalysis was to determine the efficacy and safety of cervical ripening agents in the second trimester of pregnancy in patients with previous cesarean delivery.

STUDY DESIGN

Data sources were PubMed, EMBASE, CINAHL, LILACS, Google Scholar, and clinicaltrials.gov (1983 through 2015). Eligibility criteria were cohort or cross-sectional studies that reported on efficacy and safety of cervical ripening agents in patients with previous cesarean delivery. Efficacy was determined based on the proportion of patients achieving vaginal delivery and vaginal delivery within 24 hours following administration of a cervical ripening agent. Safety was assessed by the risk of uterine rupture and complications such as retained placental products, blood transfusion requirement, and endometritis, when available, as secondary outcomes. Of the 176 studies identified, 38 met the inclusion criteria. Of these, 17 studies were descriptive and 21 studies compared the efficacy and safety of cervical ripening agents between patients with previous cesarean and those with no previous cesarean. From included studies, we abstracted data on cervical ripening agents and estimated the pooled risk differences and risk ratios with 95% confidence intervals. To account for between-study heterogeneity, we estimated risk ratios based on underlying random effects analyses. Publication bias was assessed via funnel plots and across-study heterogeneity was assessed based on the I(2) measure.

RESULTS

The most commonly used agent was PGE1. In descriptive studies, PGE1 was associated with a vaginal delivery rate of 96.8%, of which 76.3% occurred within 24 hours, uterine rupture in 0.8%, retained placenta in 10.8%, and endometritis in 3.9% in patients with ≥1 cesarean. In comparative studies, the use of PGE1, PGE2, and mechanical methods (laminaria and dilation and curettage) were equally efficacious in achieving vaginal delivery between patients with and without prior cesarean (risk ratio, 0.99, and 95% confidence interval, 0.98-1.00; risk ratio, 1.00, and 95% confidence interval, 0.98-1.02; and risk ratio, 1.00, and 95% confidence interval, 0.98-1.01; respectively). In patients with history of ≥1 cesarean the use of PGE1 was associated with higher risk of uterine rupture (risk ratio, 6.57; 95% confidence interval, 2.21-19.52) and retained placenta (risk ratio, 1.21; 95% confidence interval, 1.03-1.43) compared to women without a prior cesarean. However, the risk of uterine rupture among women with history of only 1 cesarean (0.47%) was not statistically significant (risk ratio, 2.36; 95% confidence interval, 0.39-14.32), whereas among those with history of ≥2 cesareans (2.5%) was increased as compared to those with no previous cesarean (0.08%) (risk ratio, 17.55; 95% confidence interval, 3.00-102.8). Funnel plots did not demonstrate any clear evidence of publication bias. Across-study heterogeneity ranged from 0-81%.

CONCLUSION

This systematic review and metaanalysis provides evidence that PGE1, PGE2, and mechanical methods are efficacious for achieving vaginal delivery in women with previous cesarean delivery. The use of prostaglandin PGE1 in the second trimester was not associated with significantly increased risk for uterine rupture among women with only 1 cesarean; however, this risk was substantially increased among women with ≥2 cesareans although the absolute risk appeared to be relatively small.

Foley catheter for induction of labor: potential barriers to adopting the technique

OBJECTIVE

To evaluate if a learning curve exists for cervical Foley placement for labor induction in women with unfavorable cervices and whether labor curves differ compared with the dinoprostone insert (PGE2).

STUDY DESIGN

We conducted a secondary analysis of a multicenter randomized controlled trial.

RESULT

For Foley and PGE2, successful placement occurred in 157/185 (85%) and 188/191 (98%) women (P<0.001). Unsuccessful Foley placements decreased over time (P=0.005); all occurred at the site previously using PGE2 preferentially. In women with allocated agent placed successfully who achieved complete cervical dilation, median progress with Foley (n=112), compared with PGE2 (n=123), was: 1-3 cm (6.2 vs 14.1 h; P<0.001), 3-6 cm (11.1 vs 6.7 h; P<0.001) and 6-10 cm (1.9 vs 1.5 h; P=0.14).

CONCLUSION

There is a learning curve for placing cervical Foley catheters. Despite faster times to delivery, Foley is associated with slower dilation from 3 to 6 cm compared with PGE2.

Management of Foley catheter induction among nulliparous women: a retrospective study

Background

Induction of labour is associated with increased risk for caesarean delivery among nulliparous women. The aims of this study were to evaluate the risk factors for caesarean delivery and to investigate the risk of maternal and neonatal infections in nulliparous women undergoing induction of labour by Foley catheter.

Methods

This clinical retrospective study of 432 nulliparous women with singleton pregnancy and intact amniotic membranes at or beyond 37 gestational weeks scheduled for induction of labour by Foley catheter was conducted over the course of one year, between January 2012 and January 2013, in Helsinki University Hospital. The main outcome measures were caesarean section rate and maternal and neonatal infections. Univariate and multivariate logistic regressions were used to estimate relative risks by odds ratios with 95 % confidence intervals.

Results

The caesarean section rate was 39.1 % (n = 169). In multivariate regression analysis, the factors associated with caesarean section were the need for oxytocin for labour induction [OR 2.9 (95 % CI 1.8-4.5) p < 0.001] and early epidural analgesia [OR 9.9 (95 % CI 2.1-47.5), p = 0.004]. The maternal intrapartum infection rate was 6.3 %, and the clinical neonatal infection rate was 2.8 %. In multivariate analysis, gestational diabetes was associated with maternal intrapartum infection [OR 4.3 (95 % CI 1.7-11.0, p = 0.002] and early epidural analgesia with neonatal clinical sepsis [OR 10.5 (95 % CI 1.4-76), p = 0.02].

Conclusions

Oxytocin induction and early epidural analgesia were associated with caesarean delivery. Gestational diabetes and early epidural analgesia were associated with infectious morbidity. Since the first caesarean delivery has a major impact on subsequent pregnancies, optimising labour induction among nulliparous women is important.

Foley Catheter versus Vaginal Misoprostol for Labour Induction

Objectives. To compare the efficacy and safety of intravaginal misoprostol with transcervical Foley catheter for labour induction. Material and Methods. One hundred and four women with term gestation, with Bishop score < 4, and with various indications for labour induction were randomly divided into two groups. In Group I, 25 μg of misoprostol tablet was placed intravaginally, 4 hourly up to maximum 6 doses. In Group II, Foley catheter 16F was placed through the internal os of the cervix under aseptic condition and then inflated with 50 cc of sterile saline. Statistical analysis was done using SPSS software. Results. The induction to delivery interval was 14.03 ± 7.61 hours versus 18.40 ± 8.02 hours (p < 0.01). The rate of vaginal delivery was 76.7% versus 56.8% in misoprostol and transcervical Foley catheter group, respectively. Uterine hyperstimulation was more common with misoprostol. Neonatal outcome was similar in both the groups. Conclusion. Intravaginal misoprostol is associated with a shorter induction to delivery interval as compared to Foley's catheter and it increases the rate of vaginal delivery in cases of unripe cervix at term. Transcervical Foley catheter is associated with a lower incidence of uterine hyperstimulation during labour.

Intra-vaginal prostaglandin E2 versus double-balloon catheter for labor induction in term oligohydramnios

OBJECTIVE

Compare mechanical and pharmacological ripening for patients with oligohydramnios at term.

STUDY DESIGN

Fifty-two patients with oligohydramnios ⩽ 5 cm and Bishop score ⩽ 6 were randomized for labor induction with a vaginal insert containing 10 mg timed-release dinoprostone (PGE2) or double-balloon catheter. The primary outcome was time from induction to active labor. Time to labor, neonatal outcomes and maternal satisfaction were also compared.

RESULT

Baseline characteristics were similar. Time from induction to active labor (13 with PGE2 vs 19.5 h with double-balloon catheter; P = 0.243) was comparable, with no differences in cesarean rates (15.4 vs 7.7%; P = 0.668) or neonatal outcomes. The PGE2 group had higher incidence of early device removal (76.9 vs 26.9%; P = 0.0001), mostly because of active labor or non-reassuring fetal heart rate. Fewer PGE2 patients required oxytocin augmentation for labor induction (53.8 vs 84.6% P = 0.034). Time to delivery was significantly shorter with PGE2 (16 vs 20.5 h; P = 0. 045).

CONCLUSION

Intravaginal PGE2 and double-balloon catheter are comparable methods for cervical ripening in term pregnancies with oligohydramnios.