Ripening of the uterine cervix in a post-cesarean parturient: prostaglandin E2 versus Foley catheter

The Hormonal Milieu by Different Labor Induction Methods in Women with Previous Cesarean Section: a Prospective Randomized Controlled Trial

The physiological pattern of hormonal and signaling molecules associated with labor induction is not fully clear. We conducted a preliminary study in order to investigate hormonal changes during labor induction in women with previous cesarean section. Eighty-seven women at term, with previous cesarean section, were randomized to undergo induction of labor by breast stimulation or intracervical balloon and compared with spontaneous labor (controls). Maternal serum levels of oxytocin, prostaglandin F2α, prostaglandin E2, prolactin, estradiol, and cortisol were analyzed at 0, 3, and 6 h post-induction initiation. Fetal umbilical cord hormones were measured. No significant difference was found in the induction-to-delivery time or mode of delivery between the induction groups. Maternal serum oxytocin levels decreased to a lesser extent in the breast stimulation group vs. the control group (p=0.003, p<0.001). In the breast stimulation and control groups, prostaglandin E₂ levels increased as labor progressed (p=0.005, 0.002, respectively). Prostaglandin F2α levels decreased over time in the balloon group (p=0.039), but increased in the control group (p=0.037). Both induction methods had similar outcomes. The hormonal studies ascertained the hypothesized mechanisms, with oxytocin level higher during breast stimulation and lower in balloon induction. These observations could help clinicians determine the appropriate method for cervical ripening in women with previous cesarean section. Larger future studies are needed to examine the effect of these hormonal trends on the rate of successful labor induction and complications, such as uterine rupture, in women with previous uterine scars. ClinicalTrials.gov Identifier NCT04244747.

Prevalence of uterine rupture among women with one prior low transverse cesarean and women with unscarred uterus undergoing labor induction with PGE2: A systematic review and meta-analysis

BACKGROUND

As uterine rupture may affect as many as 11/1000 women with 1 prior cesarean birth and 5/10.000 women with unscarred uterus undergoing labor induction, we intended to estimate the prevalence of such rare outcome when PGE2 is used for cervical ripening and labor induction.

METHODS

We searched MEDLINE, ClinicalTrials.gov and the Cochrane library up to September 1st 2020. Retrospective and prospective cohort studies, as well as randomized controlled trials (RCTs) on singleton viable pregnancies receiving PGE2 for cervical ripening and labor induction were reviewed. Prevalence of uterine rupture was meta-analyzed with Freeman-Tukey double arcsine transformation among women with 1 prior low transverse cesarean section and women with unscarred uterus.

RESULTS

We reviewed 956 full text articles to include 69 studies. The pooled prevalence rate of uterine rupture is estimated to range between 2 and 9 out of 1000 women with 1 prior low transverse cesarean (5/1000; 95%CI 2-9/1000, 122/9000). The prevalence of uterine rupture among women with unscarred uterus is extremely low, reaching at most 0.7/100.000 (<1/100.000.000; 95%CI <1/100.000.000-0.7/100.000, 8/17.684).

CONCLUSIONS

Uterine rupture is a rare event during cervical ripening and labor induction with PGE2.

Vaginal prostaglandin E2 versus double-balloon catheter for induction of labour for vaginal birth after caesarean section: A retrospective cohort study

OBJECTIVE

To compare the success of the double-balloon catheter (DBC) versus prostaglandin gel (PGE2) for induction of labour in women with one previous caesarean section.

DESIGN

Retrospective cohort study using routinely collected maternity data in a Tertiary NHS hospital, North West England, UK. Women with a live singleton cephalic pregnancy induced using DBC or PGE2 after one previous birth by caesarean section from 1st April 2017 to 1st July 2019 were included. The core outcomes assessed were the inability to perform artificial rupture of membranes, requirement of oxytocin, vaginal birth and uterine rupture.

RESULTS

208 women met the inclusion criteria, 127 were induced using the DBC and 81 using PGE2. The two groups were well matched for demographics and characteristics. Women induced for prolonged ruptured membranes with PGE2 were excluded from the study leaving 127 managed with DBC and 69 with PGE2. There were no significant differences observed between the two groups. Vaginal birth rates were 52.7% for the DBC and 66.6% for the PGE2 (relative risk 0.79 (confidence interval 0.63-1.00); P = 0.05). A single uterine rupture was reported following DBC usage.

CONCLUSIONS

The DBC and PGE2 appear to be equally effective for induction of labour in women with one previous caesarean section.

Morbidity associated with the use of Foley balloon for cervical ripening in women with prior cesarean delivery

OBJECTIVE

We evaluated the morbidity of Foley balloon for cervical ripening in comparison to oxytocin alone in women with a prior cesarean delivery.

STUDY DESIGN

A four-hospital retrospective review of all women with viable singleton pregnancies and history of a single prior cesarean delivery presenting for cervical ripening between 1994 and 2015. Exposure groups were either Foley balloon or oxytocin, at the treating physician's discretion. The primary outcome was defined as maternal morbidity, evaluated by a composite that included hemorrhage, and/or uterine infection, and/or uterine rupture. We defined two secondary outcomes: neonatal morbidity, and vaginal delivery rate. Neonatal morbidity was evaluated by a composite that included five-minute APGAR score <7 and/or NICU admission. We adjusted results for potential confounding variables, including hospital site, maternal age and race, initial cervical dilation, and gestational age at delivery.

RESULTS

We identified 688 patients who received ripening, 276 by Foley balloon and 412 by oxytocin. There was no significant difference in the primary outcome of maternal morbidity between groups: 38 (13.8%) in the Foley balloon group and 79 (19.2%) in the oxytocin group (aOR 1.43; 95% CI, 0.90-2.27). There was no significant difference in the secondary outcome of neonatal morbidity: 31 (11.3%) in the Foley balloon group and 51 (12.4%) in the oxytocin group (aOR 1.02; 95% CI, 0.57-1.80). The rate of vaginal delivery was significantly less in the Foley balloon group compared to the oxytocin group: 56.2% vs 64.1%, p = .037.

CONCLUSION

When cervical ripening with either Foley balloon or oxytocin was utilized at the physician's discretion in women with prior cesarean, there was no identified difference in maternal and neonatal morbidity, but the rate of successful vaginal delivery was lower.

Double-balloon catheter versus prostaglandin for cervical ripening to induce labor after previous cesarean delivery

PURPOSE

To compare the effectiveness of cervical ripening by a mechanical method (double-balloon catheter) and a pharmacological method (prostaglandins) in women with one previous cesarean delivery, an unfavorable cervix (Bishop score < 6), and a singleton fetus in cephalic presentation.

METHODS

This retrospective study, reviewing the relevant records for the years 2013 through 2017, took place in two French university hospital maternity units. This study included women with one previous cesarean delivery, a liveborn singleton fetus in cephalic presentation, and intact membranes, for whom cervical ripening, with unfavorable cervix (Bishop score < 6) was indicated for medical reasons. It compared two groups: (1) women giving birth in a hospital that uses a protocol for mechanical cervical ripening by a double-balloon catheter (DBC), and (2) women giving birth in a hospital that performed pharmacological cervical ripening by prostaglandins. The principal endpoint was the cesarean delivery rate. The secondary outcome measures were maternal and neonatal outcomes.

RESULTS

We compared 127 women with prostaglandin ripening to 117 women with DBC. There was no significant difference between the two groups for the cesarean rate (42.5% in the prostaglandin group and 42.7% in the DBC group; p = 0.973; crude OR 1.01 [0.61-1.68]; adjusted OR 1.55 [0.71-3.37]). The median interval between the start of ripening and delivery did not differ between the groups (28.7 h in the prostaglandin group vs 25.6 h in the DBC group; p = 0.880). Neonatal outcomes did not differ between the groups, either. There was one case of uterine rupture in the prostaglandin group, with no associated maternal or neonatal morbidity. There were no neonatal deaths. The postpartum hemorrhage rate was significantly higher in the DBC group.

CONCLUSION

For cervical ripening for women with one previous cesarean, the choice of a pharmacological or mechanical protocol does not appear to modify the mode of delivery or maternal or neonatal morbidity.

Cervical ripening by prostaglandin E2 in patients with a previous cesarean section

OBJECTIVE

To assess the efficacy and safety of prostaglandin in inducing labor in pregnant women with one previous cesarean section. Secondly, to evaluate predictors of successful vaginal delivery in cervical ripening by prostaglandin in these women.

STUDY DESIGN

This was an observational, retrospective, single-center study conducted in a type 3 maternity unit at Bicêtre University Hospital between January 1, 2013 and December 31, 2016. Patients with one previous cesarean section, a singleton pregnancy, a fetus in the cephalic presentation with a medical indication for induction of labor and an unfavorable cervix (Bishop score less than 6) were included in the study. Cervical ripening was performed using a dinoprostone intravaginal device for a duration of 24 h.

RESULTS

A total of 153 patients were included in the study. The rate of vaginal delivery was 55.6 % (85/153) overall and 78.3 % (36/46) in the subgroup of 46 women with a previous vaginal delivery before or after the cesarean section. There was no difference in neonatal and maternal morbidity (defined by intraoperative wounds or postpartum hemorrhage or uterine rupture) and mortality between women who delivered vaginally and women who had a cesarean section. The two cases of complete uterine rupture have been reported for patients whose labor was induced by intravaginal prostaglandin followed by intravenous oxytocin. The total maternal morbidity rate was 11.8 % (n = 8/68) in the case of emergency cesarean section. Predictors of vaginal delivery were a history of vaginal delivery, the onset of labor following cervical ripening, and a higher Bishop score before and after the 24 h following the cervical ripening.

CONCLUSION

Cervical ripening by prostaglandin after previous cesarean delivery has a 56 % success rate, with a 1.3 % risk of uterine rupture, especially when prostaglandin is combined with oxytocin. Low-risk patients should be identified to propose cervical ripening by prostaglandin.

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.

No. 155-Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section." The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

VALIDATION: These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Double-balloon catheter for induction of labor in 362 women with and without prior cesarean section

Objective

Balloon catheter is the preferred method for induction of labor in women with prior cesarean section. We sought to evaluate the rate of vaginal delivery, induction-delivery time and outcome predictors after induction with double-balloon catheter.

Study design

We conducted a retrospective cohort study including women with prior cesarean section undergoing induction of labor with a double-balloon catheter during the period January 2007–June 2014 at a large, tertiary Danish university hospital. For comparison, we included women with no prior cesarean section undergoing induction with double-balloon catheter after failed medical induction. Inclusion criteria were singleton pregnancy, an unfavorable cervix, intact membranes, cephalic presentation and either previous cesarean section or failed medical induction of labor. Exclusion criteria included contraindications for vaginal delivery, severe fetal malformation and stillbirth. Study subjects were identified in a local computerized system and data extracted from the medical records.

Results

Women with prior cesarean section (n = 304) induced with double-balloon catheter had a vaginal delivery rate of 50.3% (95% CI 44.7–55.9) compared to 51.7% (95% CI 39.2–64.1) in women with no prior cesarean section but preceding failed medical induction of labor (n = 58) (p = 0.85). BMI≥30 was associated with increased frequency of cesarean section. Median time from induction to vaginal delivery was 27.1(20.4–31.1) hours and 28.4(25.5–36.1) hours, respectively (p = 0.05). The rate of complete uterine rupture was 1.0%.

Conclusions

Similar success rates of approximately 50% for vaginal delivery were observed after induction of labor with a double-balloon catheter in women with and without prior caesarean section. A BMI ≥ 30 was associated with an increased frequency of caesarean section.

Risk of maternal, fetal and neonatal complications associated with the use of the transcervical balloon catheter in induction of labour: A systematic review

Induction of labour is one of the most frequently applied obstetrical interventions globally. Many studies have compared the use of balloon catheters with pharmacological agents. Although the safety of the balloon catheter is often mentioned, little has been written about the total spectrum of maternal and fetal morbidity associated with induction of labour using a balloon catheter. We evaluated the safety of labour induction with a transcervical balloon catheter by conducting a literature review with pooled risk assessments of the maternal, fetal and neonatal morbidity. We searched Medline, EMBASE and CINAHL as well as the Cochrane database using the Keywords 'induction of labour', 'cervical ripening', 'transcervical balloon', 'balloon catheter' and 'Foley balloon'. We did not use language or date restrictions. Randomized and quasi-randomized controlled trials as well as observational studies that contained original data on occurrence of maternal, fetal or neonatal morbidity during induction of labour with the balloon catheter were included. Studies were excluded if the balloon catheter was used concurrently with oxytocin and concurrently or consecutively with misoprostol, dinoprostone or extra-amniotic saline infusion. Study selection and quality assessment was performed by two authors independently using a standardized critical appraisal instrument. Outcomes were reported as weighted mean rates. We detected 84 articles reporting on 13,791 women. The overall risk of developing intrapartum maternal infection was 11.3% (912 of 8079 women), 3.3% (151 of 4538 women) for postpartum maternal infection and 4.6% (203 of 4460 women) for neonatal infection. Uterine hypercontractility occurred in 2.7% (148 of 5439) of the women. Uterine rupture after previous caesarean section occurred in 1.9% of women (26 of 1373), while other major maternal complications had an occurrence rate of <1%. The risk for developing minor maternal complications was <2%. The risk of developing a non-reassuring fetal heart rate was 10.8% (793 of 7336 women), 10.1% (507 of 5008 women) for fetal distress and 14.0% (460 of 3295 women) for meconium stained liquor. Neonatal death occurred in 0.29% (6 of 2058) of the deliveries and NICU admission in 7.2% (650 of 9065 deliveries). This review shows that labour induction with a balloon catheter is a safe intervention, with intrapartum maternal infection being the only reasonable risk above 10%.

Vaginal birth after cesarean section: 10 years of experience in a tertiary medical center in Taiwan

OBJECTIVE

Because of the increased risk of uterine rupture and other morbidities, instances of trial of labor after cesarean (TOLAC) have decreased in number each year. Nevertheless, under careful assessment and advanced medical care, TOLAC is still a safe option for delivery. The objective of this study is to find the factors that impact the success rate for TOLAC and to compare the results with Taiwan national registry data.

MATERIALS AND METHODS

A longitudinal cohort study that includes a total of 254 cases of women receiving TOLAC in a tertiary medical center over a period of 10 years.

RESULTS

A total of 254 participants who underwent TOLAC, which accounts for 1.67% of total labor instances (254/15,166), were enrolled for analysis. The success rate of TOLAC was found to be 80.70% (205/254), including 146 (57.5%) normal deliveries, 45 (17.7%) vacuum-assisted deliveries, and 14 (5.5%) forceps-assisted deliveries. The conversion rate to cesarean section was 19.3%. There were no uterine rupture cases in our study, and there were only two suspected cases, which turned out to have no actual rupture. When analyzing the factors affecting the results of TOLAC, we found that a successfully spontaneously delivered baby had a lower birth weight than the failed TOLAC cases that were converted to cesarean delivery (mean, 2989 g vs. 3379 g; p < 0.001). Among the patients who were converted to cesarean section, the most common reason was dysfunctional labor (79.6%), followed by fetal distress (14.3%).

CONCLUSION

Under intensive care and observation, TOLAC section may still be a feasible choice. Nevertheless, the body weight of the baby has been shown to be a factor that can influence the success rate.

Trial of labour after caesarean section: Two-year analysis at a Portuguese centre

We conducted a retrospective study aimed at determining variables associated with a higher success rate for vaginal delivery after caesarean section, and assessing the impact of induction of labour. Secondarily, we aimed to describe our vaginal delivery and uterine rupture rates with the use of a controlled-release dinoprostone vaginal insert for cervical ripening. Of 292 women who met the inclusion criteria, induction of labour occurred in 48% (94% with dinoprostone). There was a non-significant difference between the vaginal delivery rate of spontaneous labour (57%) and induction of labour (33%), after adjusting for confounding variables. The success rate was influenced by a Bishop score ≥6, previous vaginal delivery and previous caesarean for dystocia or failed induction. There was only one case of uterine rupture, which was associated with dinoprostone use (overall rate 0.34%, 0.77% for dinoprostone). Impact statement Trial of labour after caesarean section is considered an alternative to elective repeat caesarean. Both present associated benefits and risks, the most fearsome of which is uterine rupture during labour (0.78% in term pregnancies). Induction is also possible but carries a higher risk of uterine rupture and lower success rate for vaginal birth. Prostaglandins have been of particular concern due to a higher risk of uterine scar rupture, estimated at 2% for dinoprostone; however, its use as a controlled-release vaginal insert has been under-reported. Our study confirms the reported impact of previous vaginal delivery, previous caesarean indication and Bishop score at admission on success rate for vaginal birth after caesarean. We were unable to prove a lower success rate for induction of labour after adjusting for other variables. Despite our study limitations, we report on the use of a controlled-release vaginal insert with 10mg of dinoprostone in 130 women with a uterine rupture rate of 0.77%, lower than previously reported and similar to the overall rate estimated for term pregnancies. This dinoprostone formulation may be safer than previously reported but larger studies, and preferably randomised controlled trials, are needed to confirm these findings.

Comparison of induction of labor methods for unfavorable cervices in trial of labor after cesarean delivery

OBJECTIVE

To compare induction of labor methods in patients attempting a trial of labor after cesarean (TOLAC) with an unfavorable cervix.

METHODS

This is a retrospective cohort study from patients attempting TOLAC from 2009 to 2013. Patients with a simplified Bishop score of three or less where labor was initiated with either a Cook balloon or oxytocin were included. Our primary outcome was mode of delivery. Our secondary outcomes included duration of labor and multiple maternal and neonatal morbidities.

RESULTS

Two-hundred and fourteen women met inclusion criteria: 150 received oxytocin and 64 had the Cook balloon placed. The vaginal birth after cesarean delivery rate was significantly higher in the oxytocin group at 70.7% versus 50.0% in the Cook balloon group (p = 0.004). In the multivariable analysis, odds for cesarean delivery were two times higher with the Cook balloon than with oxytocin (Adjusted OR = 2.09, 95% CI = 1.05-4.18, p = 0.036). The duration of labor was longer with the Cook balloon versus oxytocin (21.9 versus 16.3 hours, p = 0.0002). There were no significant differences in maternal and neonatal health outcomes.

CONCLUSION

Oxytocin induction of labor was associated with a higher rate of vaginal delivery and a shorter duration of labor compared to the Cook balloon in women undergoing TOLAC with an unfavorable cervix.

Back to "once a caesarean: always a caesarean"? A trend analysis in Switzerland

PURPOSE

Caesarean sections (CS) have significantly increased worldwide and a previous CS is nowadays an important and increasingly reported indication to perform a repeat CS. There is a paucity of information in Switzerland on the incidence of repeat CS after previous CS and relationship between the rates of vaginal birth after CS (VBAC). The aim of this study was to analyse the actual trend in VBAC in Switzerland.

METHODS

We performed a retrospective cohort study to analyse the proportion of VBAC among all pregnant women with previous sections which give birth during two time periods (group 1:1998/1999 vs. group 2:2004/2005) in our tertiary care referral hospital and in the annual statistics of Swiss Women's Hospitals (ASF-Statistics). In addition, the proportion of induction of labour after a previous caesarean and its success was analysed.

RESULTS

In both cohorts studied, we found a significant decrease of vaginal births (p < 0.05) and a significant increase of primary elective repeat caesarean section (p < 0.05) from the first to the second time period, while there was a decrease of secondary repeat caesarean sections. The prevalence of labour induction did not decrease.

CONCLUSION

Our study shows that vaginal birth after a prior caesarean section has decreased over time in Switzerland. There was no significant change in labour induction during the study period. While this trend might reflect an increasing demand for safety in pregnancy and childbirth, it concomitantly increases maternal risks of further pregnancies, and women need to be appropriately informed about long-term risks.

An elevated amniotic fluid prostaglandin F2α concentration is associated with intra-amniotic inflammation/infection, and clinical and histologic chorioamnionitis, as well as impending preterm delivery in patients with preterm labor and intact membranes

OBJECTIVE

To determine whether an elevated amniotic fluid concentration of prostaglandin F2α (PGF2α) is associated with intra-amniotic inflammation/infection and adverse pregnancy outcomes in patients with preterm labor and intact membranes.

MATERIALS AND METHODS

The retrospective cohort study included 132 patients who had singleton pregnancies with preterm labor (< 35 weeks of gestation) and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for genital mycoplasmas. Intra-amniotic inflammation was defined by an elevated amniotic fluid matrix metalloproteinase-8 (MMP-8) concentration (>23 ng/mL). PGF2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF2α concentration was considered elevated when it was above the 95th percentile among pregnant women at 15-36 weeks of gestation who were not in labor (≥170 pg/mL).

RESULTS

(1) The prevalence of an elevated amniotic fluid PGF2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF2α concentration had a significantly higher rate of positive amniotic fluid culture [19% (10/53) versus 5% (4/79); p = 0.019], intra-amniotic inflammation/infection [49% (26/53) versus 20% (16/79); p = 0.001], spontaneous preterm delivery, clinical and histologic chorioamnionitis, and funisitis, as well as a higher median amniotic fluid MMP-8 concentration and amniotic fluid white blood cell count and a shorter amniocentesis-to-delivery interval than those without an elevated concentration of amniotic fluid PGF2α (p < 0.05 for each); and (3) an elevated amniotic fluid PGF2α concentration was associated with a shorter amniocentesis-to-delivery interval after adjustment for the presence of intra-amniotic inflammation/infection [hazard ratio 2.1, 95% confidence interval (CI) 1.4-3.1; p = 0.001].

CONCLUSION

The concentration of PGF2α was elevated in the amniotic fluid of 40.2% of patients with preterm labor and intact membranes and is an independent risk factor for intra-amniotic inflammation/infection, impending preterm delivery, chorioamnionitis, and funisitis.

Double-balloon catheter and sequential vaginal prostaglandin E2 versus vaginal prostaglandin E2 alone for induction of labor after previous cesarean section

PURPOSE

To evaluate the efficacy of inducing labor using a double-balloon catheter and vaginal prostaglandin E2 (PGE2) sequentially, in comparison with vaginal PGE2 alone after previous cesarean section.

METHODS

A total of 264 pregnant women with previous cesarean section undergoing labor induction at term were included in this prospective multicentre cohort study. Induction of labor was performed either by vaginal PGE2 gel or double-balloon catheter followed by vaginal PGE2. The primary outcome measure was the cesarean section rate.

RESULTS

The cesarean section rate was 37 % without any statistically significant difference between the two groups (PGE2: n = 41, 37 % vs. balloon catheter/PGE2: n = 41, 42 %; P = 0.438). The median (range) number of applications of PGE2 [2 (1-10) versus 1 (0-8), P < 0.001] and the total amount of PGE2 used in median (range) mg [2 (1-15) vs. 1 (0-14), P = 0.001] was less in the balloon catheter/PGE2 group. Factors significantly increasing risk for cesarean section were "no previous vaginal delivery" (OR 5.391; CI 2.671-10.882) and "no oxytocin augmentation during childbirth" (OR 2.119; CI 1.215-3.695).

CONCLUSIONS

The sequential application of double-balloon catheter and vaginal PGE2 is as effective as the sole use of vaginal PGE2 with less applications and total amount of PGE2.

Induction of labor in women with a prior cesarean delivery

Given the historically high rates of cesarean delivery in the United States, obstetrical providers must often consider an induction of labor for women with a history of prior cesarean delivery versus repeat cesarean delivery. Clinical evaluation of this scenario involves weighing the benefits of a successful trial of labor after cesarean delivery against the risks associated with symptomatic uterine rupture. This article will review the uncommon but clinically important circumstance of labor induction following a cesarean delivery, including method of induction as well as induction in the setting of second trimester still birth and fetal anomalies.

Umbilical cord prostaglandins in term and preterm parturition

OBJECTIVE

Prostaglandins (PGs) are considered the universal mediators of parturition. Amniotic fluid PGE2 and PGF2α concentrations increase before the onset of spontaneous labor at term, as well as during labor. This study was conducted to determine if the concentrations of umbilical cord PGE2 and PGF2α change with advancing gestational age, spontaneous labor at term, and preterm labor (with and without funisitis).

METHODS

Umbilical cord (UC) tissue samples were obtained from women (N = 158) with singleton pregnancies in the following groups: (1) term deliveries without labor (TNL; n = 20); (2) term deliveries with labor (TIL; n = 20); (3) spontaneous preterm deliveries (sPTD) with (n = 20) and without acute funisitis (n = 20); and (4) preeclampsia without labor (n = 78). The concentrations of PGs were determined in different locations of the UC. PGE2 and PGF2α were measured by specific immunoassays. Non-parametric statistics were used for analysis.

RESULTS

(1) In spontaneous preterm deliveries, the median UC PGE2 concentration was higher in cases with funisitis than in those without funisitis (233.7 pg/µg versus 87.4 pg/µg of total protein, p = 0.001); (2) the median UC PGE2 concentration in sPTD with funisitis was also higher than that obtained from samples who had undergone labor at term (233.7 pg/µg versus 116.1 pg/µg of total protein, p = 0.03); (3) the UC PGE2 and PGF2α concentration increased as a function of advancing gestational age before 36 weeks (PGE2: ρ = 0.59, p < 0.001; PGF2α: ρ = 0.39, p = 0.01), but not after 36 weeks (PGE2: ρ = -0.1, p = 0.5; PGF2α: ρ = -0.2, p = 0.2); (4) the median UC concentrations of PGE2 and PGF2α at term was similar in samples obtained from women with and without labor (PGE2: TNL 133.7 pg/µg versus TIL 116.1 pg/µg of total protein, p = 0.9; PGF2α: TNL 8.4 pg/µg versus TIL 8.1 pg/µg of total protein, p = 0.7); and (5) there was no correlation between UC PG concentration and gestational age at term pregnancy (PGE2: ρ = 0.01, p = 0.9; PGF2α: ρ = 0.07, p = 0.7).

CONCLUSIONS

(1) PGE2 concentrations in the UC are higher in the presence of acute funisitis than in the absence of this lesion; (2) spontaneous labor at term was not associated with a change in the UC concentration of PGE2 and PGF2α; and (3) the UC concentrations of PGE2 and PGF2α increased as a function of gestational age. We propose that UC PGs act as inflammatory mediators generated in the context of fetal systemic inflammation.

Efficacy and safety of labour induction in patients with a single previous caesarean section: a proposal for a clinical protocol

PURPOSE

To evaluate the efficacy and safety of induction in women with a single prior Caesarean section.

METHODS

This was a cohort study in which we included all singleton pregnancies in patients with a single prior Caesarean who delivered between 2007 and 2012. Methods of induction were ocytocic infusion plus amniotomy (if Bishop score ≥6) or insertion of a Foley catheter (Bishop <6).

RESULTS

Of the 2,075 patients included, 806 (38.8 %) had an elective repeat Caesarean, 1,045 (50.4 %) went into spontaneous labour, 89 (4.3 %) were induced by artificial rupture of the membranes and infusion of ocytocics and 135 (6.5 %) were induced using a Foley catheter. Rates of vaginal delivery were 79.2, 79.8 and 43.7 %, respectively. Six cases of uterine rupture were reported in the group of patients who went into spontaneous labour. There was no difference between groups with regard to neonatal morbidity. On multivariate analysis, risk factors for Caesarean delivery were macrosomia (OR 2.04, 95 % CI 1.31-3.18) and induction by Foley catheter (OR 3.73, 95 % CI 2.47-5.62); protective factors were previous vaginal delivery (OR 0.41, 95 % CI 0.29-0.57) and cervical dilatation (OR 0.84, 95 % CI 0.78-0.91).

CONCLUSIONS

Uterine induction after a single Caesarean section with ocytocic infusion and amniotomy where the cervix is favourable does not appear to entail any significant added risk in terms of maternal or foetal morbidity. Foley catheter induction is a reasonable option if the cervix is not ripe.

Cervical ripening with Foley catheter for induction of labor after cesarean section: a cohort study

OBJECTIVE

To evaluate spontaneous vaginal delivery and complication rates after induction of labor with a transcervical Foley catheter in women with a previous cesarean delivery.

DESIGN

Retrospective cohort study.

SETTING

Secondary teaching hospital in the second largest city of the Netherlands.

POPULATION

Women with a history of cesarean delivery (n = 208), undergoing induction of labor with a Foley catheter in a subsequent pregnancy.

MATERIAL AND METHODS

The women who had induction of labor with a transcervical Foley catheter in the Ikazia Hospital, Rotterdam, between January 2003 and January 2012, were identified in a computerized database. Patient's records were checked for accuracy.

MAIN OUTCOME MEASURES

Vaginal delivery rate, cesarean section rate, uterine rupture and maternal and neonatal (infectious) morbidity.

RESULTS

Of the women 60% had a spontaneous vaginal delivery and 11% were delivered by vacuum extraction. Uterine rupture occurred in one woman. Postpartum hemorrhage was the most common maternal complication (12%). Maternal intrapartum and postpartum infections occurred in 5% and 1%. Proven neonatal infection was found in 3% of the cases. Two perinatal deaths occurred (1%), of which one was related to uterine rupture.

CONCLUSION

Induction of labor with a transcervical Foley catheter is an effective method to achieve vaginal delivery in women with a previous cesarean delivery. There is a low risk of uterine rupture and maternal and neonatal (infectious) morbidity in this cohort.

[National Survey of the management and delivery of the unicicatriciel uterus in France in 2009]

OBJECTIVES

To audit French maternity units' obstetric procedures in delivering women who have undergone previous caesarean section.

MATERIAL AND METHODS

[corrected] Survey by questionnaire collecting the obstetrical practices about agreement and methods of delivery of women with previous caesarean section in France in 2009. The questionnaire was sent by email to 472 private and public maternity units of grades 1, 2 and 3.

RESULTS

One hundred and seventy-five units (37%) replied, about 305,710 new-borns representated, few private maternity units answered (12.6% of the answers), despite their accounting for 30.2% of obstetric work; 50.9% had no written policy for the management of patients with previous caesarean; 53.1% of units relied on written consent from women attempting vaginal delivery after previous caesarean. The documentation concerning previous caesarean section was considered important by 73.1% of units. Rates for acceptance of attempted vaginal delivery were as follows: after a transverse lower uterine segment incision - 100% of maternity units; after a transverse corporeal incision - 30.3% of units and after a vertical incision - 25.1% of units; 55.4% of maternities induced labour after a previous caesarean section, 29.9% of them with prostaglandin E2; 64% used internal tocometry. Radiopelvimetry was a routine examination for 55.9% of grade 1 units, compared with 13.5% of grade 3 (P=0.000035). Induction was practised by more grade 3 units (78.3%) than grade 1 units (44%) (P=0.009). No team acknowledged carrying out subsequent caesarean delivery as a matter of principle.

CONCLUSIONS

This national survey, statistically representative in terms of the numbers of deliveries, gives an objective view of different practices, according to type and grade of maternity unit in France, in 2009. The data indicate that it is desirable to devise specific recommendations in order to harmonise management, bearing in mind the frequency of caesarean sections.

The views of obstetricians in the south-west of England on the use of prostaglandins and syntocinon in VBAC

The aim of our study was to explore the views of consultant obstetricians in the south-west of England on the use of prostaglandin and oxytocin in women undergoing vaginal birth after caesarean delivery (VBAC), and assess how the perceived risk of uterine rupture in such a cohort of women affected their practice. A postal questionnaire was sent to randomly selected consultant obstetricians in the south-west of England. The response rate from the survey was 59.2%. The study showed that the willingness of consultants to use prostaglandin in VBAC was related to their length of practice. Some 89.7% of all respondents claim they would use syntocinon for augmentation in VBAC; 75% of all the responding consultants who have been in the post for longer than 10 years claim they would not use either of the agents in VBAC. We conclude that, despite concerns about the risks of increased uterine rupture in both induction and augmentation in labour of women undergoing VBAC, our study did not seem to support the fact that obstetricians' practices are influenced by this perceived risk.

Mechanical Methods of Cervical Ripening and Labor Induction

This article reviews the safety and efficacy of mechanical agents for cervical ripening. Hygroscopic dilators, balloon catheters, and devices designed for cervical ripening have all been shown to be safe and effective for cervical ripening. Mechanical agents are as efficacious as other agents for cervical ripening. However, there is no method that has been conclusively shown to improve mode of delivery or perinatal outcome. The advantages of preinduction cervical ripening with mechanical devices include low cost, low incidence of systemic side effects, and low risk of uterine hyperstimulation.

Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section". The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

1. Provided there are no contraindications, a woman with 1 previous transverse low-segment Caesarean section should be offered a trial of labour (TOL) with appropriate discussion of perinatal risks and benefits. The process of informed consent with appropriate documentation should be an important part of the birth plan in a woman with a previous Caesarean section (II-2B). 2. The intention of a woman undergoing a TOL after Caesarean section should be clearly stated, and documentation of the previous uterine scar should be clearly marked on the prenatal record (II-2B). 3. For a safe labour after Caesarean section, a woman should deliver in a hospital where a timely Caesarean section is possible. The woman and her health care provider must be aware of the hospital resources and the availability of obstetric, anesthetic, pediatric, and operating-room staff (II-2A). 4. Each hospital should have a written policy in place regarding the notification and (or) consultation for the physicians responsible for a possible timely Caesarean section (III-B). 5. In the case of a TOL after Caesarean, an approximate time frame of 30 minutes should be considered adequate in the set-up of an urgent laparotomy (III-C). 6. Continuous electronic monitoring of women attempting a TOL after Caesarean section is recommended (II-2A). 7. Suspected uterine rupture requires urgent attention and expedited laparotomy to attempt to decrease maternal and perinatal morbidity and mortality (II-2A). 8. Oxytocin augmentation is not contraindicated in women undergoing a TOL after Caesarean section (11-2A). 9. Medical induction of labour with oxytocin may be associated with an increased risk of uterine rupture and should be used carefully after appropriate counselling (II-2B). 10. Medical induction of labour with prostaglandin E2 (dinoprostone) is associated with an increased risk of uterine rupture and should not be used except in rare circumstances and after appropriate counselling (II-2B). 11. Prostaglandin E1 (misoprostol) is associated with a high risk of uterine rupture and should not be used as part of a TOL after Caesarean section (II-2A). 12. A foley catheter may be safely used to ripen the cervix in a woman planning a TOL after Caesarean section (II-2A). 13. The available data suggest that a trial of labour in women with more than 1 previous Caesarean section is likely to be successful but is associated with a higher risk of uterine rupture (II-2B). 14. Multiple gestation is not a contraindication to TOL after Caesarean section (II-2B). 15. Diabetes mellitus is not a contraindication to TOL after Caesarean section (II-2B). 16. Suspected fetal macrosomia is not a contraindication to TOL after Caesarean section (II-2B). 17. Women delivering within 18 to 24 months of a Caesarean section should be counselled about an increased risk of uterine rupture in labour (II-2B). 18. Postdatism is not a contraindication to TOL after Caesarean section (II-2B). 19. Every effort should be made to obtain the previous Caesarean section operative report to determine the type of uterine incision used. In situations where the scar is unknown, information concerning the circumstances of the delivery is helpful in determining the likelihood of a low transverse incision. If the likelihood of a low transverse incision is high, a TOL after Caesarean section can be offered (II-2B).

VALIDATION

These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.

Cervical Ripening With Transcervical Foley Catheter and the Risk of Uterine Rupture

OBJECTIVE

To estimate whether the rate of uterine rupture in patients with a previous cesarean delivery is related to labor induction and/or cervical ripening using transcervical Foley catheter.

METHODS

Charts of all patients who had a trial of labor after a previous cesarean delivery in our institution between 1988 and 2002 were reviewed. The rates of successful vaginal birth after cesarean delivery and uterine rupture in patients with spontaneous labor (control group) were compared with those of patients who underwent a labor induction by means of amniotomy with or without oxytocin and patients who underwent a labor induction/cervical ripening using a transcervical Foley catheter. Logistic regression analysis was performed to adjust for confounding variables.

RESULTS

Of 2479 patients, 1807 had a spontaneous labor, 417 had labor induced by amniotomy with or without oxytocin, and 255 had labor induced by using transcervical Foley catheter. The rate of successful vaginal birth after cesarean delivery was significantly different among the groups (78.0% versus 77.9% versus 55.7%, P <.001), but not the rate of uterine rupture (1.1% versus 1.2% versus 1.6%, P =.81). After adjusting for confounding variables, the odds ratio (OR) for successful vaginal birth after cesarean delivery was 0.68 (95% confidence interval [CI] 0.41, 1.15), and the OR for uterine rupture was 0.47 (95% CI 0.06, 3.59) in patients who underwent an induction of labor using a transcervical Foley catheter when compared with patients with spontaneous labor.

CONCLUSION

Labor induction using a transcervical Foley catheter was not associated with an increased risk of uterine rupture.

Induction of labour with an unfavourable cervix

Labour induction is undertaken when the advantages for the mother and/or the baby are considered to outweigh the disadvantages. When the uterine cervix is unfavourable, oxytocin, with or without amniotomy, is frequently ineffective. Vaginal prostaglandin E(2) is most commonly used if it is affordable. Evidence regarding many alternative methods is discussed in this chapter. Of particular interest are misoprostol and extra-amniotic saline infusion.Misoprostol, an orally active prostaglandin E(1) analogue, has been used widely by the vaginal and oral routes for labour induction at or near term. Several recent trials have confirmed that it is highly effective. Overall Caesarean section rates appear to be reduced, despite a relative increase in Caesarean sections for fetal heart rate abnormalities. Concern remains regarding increased rates of uterine hyperstimulation and meconium-stained amniotic fluid, although data on perinatal outcome have been reassuring. Postpartum haemorrhage may be increased following labour induction with misoprostol, and isolated reports of uterine rupture, with or without previous Caesarean section, have appeared. Using small dosages appears to reduce adverse outcomes. Very large trials are needed to evaluate rare adverse outcomes.Extra-amniotic saline infusion is an effective method which appears to reduce the risk of uterine hyperstimulation that occurs with the use of exogenous uterotonics.