Uterine Rupture During Trial of Labor: Controversy of Induction’s Methods

Oxytocin augmentation and neurotransmitters in prolonged delivery: An experimental appraisal

The uterus is a highly innervated organ, and during labor, this innervation is at its highest level. Oxytocinergic fibers play an important role in labor and delivery and, in particular, the Lower Uterine Segment, cervix, and fundus are all controlled by motor neurofibers. Oxytocin is a neurohormone that acts on receptors located on the membrane of the smooth cells of the myometrium. During the stages of labor and delivery, its binding causes myofibers to contract, which enables the fundus of the uterus to act as a mediator. The aim of this study was to investigate the presence of oxytocinergic fibers in prolonged and non-prolonged dystocic delivery in a cohort of 90 patients, evaluated during the first and second stages of labor. Myometrial tissue samples were collected and evaluated by electron microscopy, in order to quantify differences in neurofibers concentrations between the investigated and control cohorts of patients. The authors of this experiment showed that the concentration of oxytocinergic fibers differs between non-prolonged and prolonged dystocic delivery. In particular, in prolonged dystocic delivery, compared to non-prolonged dystocic delivery, there is a lower amount of oxytocin fiber. The increase in oxytocin appeared to be ineffective in patients who experienced prolonged dystocic delivery, since the dystocic labor ended as a result of the altered presence of oxytocinergic fibers detected in this group of patients.

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.

Heterogenous use of misoprostol for induction of labour: results of an online survey among midwives in German-speaking countries

PURPOSE

This online survey looked at the experiences and general perceptions of midwives concerning induction of labour and the specific use of misoprostol.

METHODS

We published an online questionnaire with 24 questions in German on midwives' experiences and perceptions of different methods of induction of labour.

RESULTS

The online survey was answered by 412 midwives between February 2016 and February 2017. At least 20% of the 24 questions were answered in 333 questionnaires, which were included in this analysis. Oral misoprostol was the most common induction method for primipara and for women with a previous vaginal birth and an unfavourable cervix. Apart from alternative methods for induction of labour like castor oil and complementary/alternative methods, oral misoprostol was the preferred method of induction of labour by midwives. Midwives described a wide range of dosage schedules concerning application intervals, starting doses, and the maximum daily dose of misoprostol. Approximately 50% of the participants of this study described prescriptions of more than 200 µg misoprostol daily for induction of labour.

CONCLUSION

Misoprostol is widely used in Germany and was one of the three preferred methods of induction of labour among midwives in our study next to castor oil and complementary/alternative methods. The preparation and dosage of misoprostol vary significantly among hospitals and do not adhere to international guidelines. Midwives voiced their concerns about inconsistent indications and heterogenous use of different methods and dosages of induction. They wished for more patience with late-term pregnancies and individualized shared decision-making between pregnant women and obstetricians.

Labour Induction with Misoprostol in German Obstetric Clinics: What Are the Facts on Such Use?

Subject While the synthetic prostaglandin E1 analogue misoprostol is the most effect labour induction agent, its use is off-label for the most part. For this reason, and in view of its potential adverse effects and varying approaches to its administration, the drug has recently once again become a focus of critical attention. The objective of this survey was thus to establish a record of labour induction with misoprostol in German clinics and determine the impact of the negative reporting on everyday obstetric practice. Material and Methods In this cross-sectional study, 635 obstetrics and gynaecology departments in Germany were requested by email to participate in our survey in February/March 2020. Online responses to 19 questions were requested regarding the clinic, use of misoprostol before and after the critical reporting, use of misoprostol (sourcing, method of administration, dosage, monitoring) and other labour induction methods. Results A total of 262 (41.3%) of the clinics solicited for the survey completed the questionnaire. There were no differences regarding the care level (Perinatal Centre Level I, Perinatal Centre Level II, Clinic with Perinatal Focus or Obstetric/Private Clinic; p = 0.2104) or birth counts (p = 0.1845). In most cases, misoprostol was prepared in the clinic's own pharmacy (54%) or imported from another country (46%) and administered orally in tablet form (95%). Misoprostol dosage levels varied (25 µg [48%], 50 µg [83%], 75 µg [6%], 100 µg [47%] and > 100 µg [5%]). Most of the clinics used premanufactured tablets/capsules (59%), although Cytotec tablets were also divided (35%) or dissolved in water (5%). Misoprostol administration intervals were mainly every 4 hours (64%) or every 6 hours (30%). CTG checks were run in most cases before and after administration of a dose of misoprostol (78% and 76%) and before and after administration of a dose of prostaglandin E2 (both 88%). Presence of contractions led to no misoprostol (59%) or no prostaglandin E2 (64%) being administered in most cases. The critical reporting resulted in discontinuation of use of misoprostol in 17% of the clinics - mainly smaller obstetric/private clinics with fewer than 1000 births. Labour cocktails were used mainly in obstetric and private clinics (61%). Conclusion Misoprostol is an established agent for labour induction in German clinics. The dosing schemes used vary. Improvements of currently common management practices are required, especially in the area of labour induction (CTG checks before and after administration of labour-inducing medication, no administration of prostaglandin if contractions are ongoing). The discussion of use of misoprostol in the media resulted in stoppage of its use mainly in smaller clinics.

The urological complications of vaginal birth after cesarean (VBAC) - a literature review

The appearance of urological complications is a major problem in obstetrics and gynecologic surgery; the bladder is the most common damaged organ. Due to a continuous increase in the rate of cesareans, the incidence of urologic complications will be potentially higher. We reviewed the most important risk factors for urinary tract injury and analyzed the strategies necessary to avoid these situations during vaginal birth after cesarean (VBAC). The risks and benefits of VBAC should be balanced before deciding the mode of delivery.

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.

Balloon catheter for induction of labor in women with one previous cesarean and an unfavorable cervix

Introduction

When women with a previous cesarean section and an unfavorable cervix have an indication for delivery, the choice is to induce labor or to perform a cesarean section. This study aims to assess the effectiveness and safety of a balloon catheter as a method of induction of labor in women with one previous cesarean section and an unfavorable cervix compared with an elective repeat cesarean section.

Material and methods

We performed a prospective cohort study in 51 hospitals in the Netherlands on term women with one previous cesarean section, a live singleton fetus in cephalic position, an unfavorable cervix and an indication for delivery. We recorded obstetric, maternal and neonatal characteristics. We compared the outcome of women who were induced with a balloon catheter with the outcome of women who delivered by elective repeat cesarean section. Main outcomes were maternal and neonatal morbidity. Mode of delivery was a secondary outcome for women who were induced. Adjusted odds ratios (aOR) were calculated using logistic regression, adjusted for potential confounders.

Results

Analysis was performed on 993 women who were induced and 321 women who had a repeat cesarean section (August 2011 until September 2012). Among the women who were induced, 560 (56.4%) delivered vaginally and 11 (1.1%) sustained a uterine rupture. Composite adverse maternal outcome (uterine rupture, severe postpartum hemorrhage or postpartum infection) occurred in 73 (7.4%) in the balloon and 14 (4.5%) women in the repeat cesarean section group (aOR 1.58, 95% confidence interval [CI] 0.85‐2.96). Composite adverse neonatal outcome (Apgar score <7 at 5 minutes or umbilical pH <7.10) occurred in 57 (5.7%) and 10 (3.2%) neonates, respectively (aOR 1.40, 95% CI 0.87‐3.48). Women who were induced had a shorter postpartum admission time (2.0 vs 3.0 days (P < 0.0001)).

Conclusions

In women with a previous cesarean section and a need for delivery, induction of labor with a balloon catheter does not result in a significant increase in adverse maternal and neonatal outcomes as compared with planned cesarean section.

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.

[Risk of uterine rupture in vaginal birth after cesarean: Systematic review]

OBJECTIVE

To assess the risk of uterine rupture (UR) in attempted vaginal birth after cesarean and to identify risk factors.

METHODS

Systematic review by consulting the following databases: PubMed (MEDLINE), Cochrane Library Plus, Embase, Nursing@Ovid, Cuidatge and Dialnet. The search was conducted between January and March 2015. MeSH descriptors used were: vaginal birth after cesarean; uterine rupture; labor induced and labor obstetric or trial of labor. There were no restrictions on date or language. The selection of articles was performed by 2 independent reviewers, standardized and unblinded. A critical review of the summary was conducted, and if was necessary, the full text was consulted. Prospective and retrospective documents were included.

RESULTS

A total of 39 documents were included for their relevance and interest. Few clinical trials were found. The UR incidence on the results of the studies analyzed ranged from 0.15-0.98% in spontaneous labor; 0.3-1.5% in stimulation and induction with oxytocin, and 0.68-2.3% in prostaglandin inductions.

CONCLUSIONS

The success of vaginal birth after cesarean is important and improves when conditions are optimal. However it is not without risks, the main one being UR. Induction of labor with oxytocin and/or prostaglandins appears as the main risk factor, while the spontaneous onset of labor and a prior vaginal birth are protective factors.

Misoprostol for Labour Induction after Previous Caesarean Section - Forever a "No Go"?

Misoprostol in oral or vaginal form is an established method of labour induction worldwide. Its use after previous caesarean section is associated with a high rate of uterine rupture; according to international guidelines it is therefore contraindicated in this setting. However the evidence base for this recommendation comprises case reports, one randomised trial that was discontinued prematurely, and numerous low quality retrospective data analyses published between 1997 and 2004. New insights into e.g. resorption kinetics, dosage and application intervals, dose dependant uterine hyperstimulation rates, as well as increasing clinical experience with misoprostol have lead to a critical reappraisal of these "historical" studies. Accordingly the evidence supporting a ban on vaginal and particularly oral misoprostol for labour induction in the context of a scarred uterus is currently insufficient for a convincing guideline recommendation. In view of the clear advantages of misoprostol over prostaglandin E₂ (cheaper, more effective) a retrospective review of registry data should be conducted to determine the incidence of uterine rupture following misoprostol and the circumstances in which it occurs. A prospective, randomised trial could then be conducted on the basis of these findings (e.g. oral misoprostol vs. vaginal prostaglandin E₂); known risk factors for uterine rupture including the type of uterine scar would need to be taken into account when selecting patients for vaginal delivery. Until new data from well-designed studies are available, misoprostol will continue to be contraindicated in clinical guidelines for use in labour induction after previous caesarean section.

Women's reasons for, and experiences of, choosing a homebirth following a caesarean section

Background

Caesarean section is rising in the developed world and vaginal birth after caesarean (VBAC) is declining. There are increased reports of women seeking a homebirth following a caesarean section (HBAC) in Australia but little is known about the reasons for this study aimed to explore women's reasons for and experiences of choosing a HBAC.

Methods

Twelve women participated in a semi-structured one-to-one interview. The interviews were digitally recorded, then transcribed verbatim. These data were analysed using thematic analysis.

Results

The overarching theme that emerged was ‘It’s never happening again’. Women clearly articulated why it [caesarean section] was never happening again under the following sub themes: ‘treated like a piece of meat’, ‘I was traumatised by it for years’, ‘you can smell the fear in the room’, ‘re-traumatised by the system’. They also described how it [caesarean section] was never happening again under the sub themes: ‘getting informed and gaining confidence’, ‘avoiding judgment through selective telling’, ‘preparing for birth’, ‘gathering support’ and ‘all about safety but I came first’. The women then identified the impact of their HBAC under the subthemes ‘I felt like superwoman’ and ‘there is just no comparison’.

Conclusions

Birth intervention may cause physical and emotional trauma that can have a significant impact on some women. Inflexible hospital systems and inflexible attitudes around policy and care led some women to seek other options. Women report that achieving a HBAC has benefits for the relationship with their baby. VBAC policies and practices in hospitals need to be flexible to enable women to negotiate the care that they wish to have.