What Is A Failed Labor Induction?

Cook's balloon versus dinoprostone for Labour induction of term pregnancies with fetal GROWth restriction: study protocol for a randomised controlled trial in tertiary maternity hospitals in Spain (COLIGROW study)

INTRODUCTION

Fetal growth restriction (FGR) affects about 3%-5% of term pregnancies. If prenatally detected and anterograde umbilical artery flow is preserved (stage I), it is recommended to deliver at term (≥ 37+0 weeks). In the absence of contraindications, the vaginal route is preferred, and labour induction is usually required. It has been postulated that mechanical methods for cervical ripening may have an optimal profile for the induction of term FGR fetuses since they are associated with less uterine stimulation than the standard pharmacological methods, and therefore, could be better tolerated by fetuses with reduced placental reserve. This study aims to evaluate whether cervical ripening with a Cook's balloon for the induction of labour from 37+0 weeks of gestation in the stage I FGR manages to increase the rate of vaginal delivery compared with vaginal dinoprostone.

METHODS AND ANALYSIS

This will be an open-labelled, randomised, parallel-group clinical trial to be held in five Spanish maternities. Women aged ≥18 years with singleton pregnancies complicated with stage I FGR (defined as the presence of at least one of these two criteria: (1) estimated fetal weight (EFW) <3rd percentile; (2) EFW <10th percentile and at least one of the following: (2.1.) umbilical artery pulsatility index >95th percentile and presence of antegrade end-diastolic flow or (2.2.) Cerebroplacental ratio <5th percentile), gestational age dated by first-trimester ultrasound ≥37+0 weeks at the time of labour induction, cephalic presentation, unfavourable cervix (Bishop score <7), intact fetal membranes, no previous caesarean section and no maternal or fetal contraindications for vaginal delivery or labour induction will be 1:1 randomised by centre to labour induction with Cook's balloon (experimental arm) or dinoprostone (control arm). FGR cases with evidence of non-placental origin (major structural fetal malformations, chromosomal anomalies or congenital infection) will be excluded. The primary outcome is the achievement of a vaginal delivery and it will be assessed by comparing the rates of vaginal delivery in each group using the one-sided χ2 test at an alpha level of 0.025. The sample size has been estimated to observe an expected 84% of vaginal deliveries with Cook's balloon vs 62% with dinoprostone. Therefore, a total of 172 patients (86 per arm) are required (power of 90%, alpha level of 0.025, assuming a percentage of losses of 5%). The efficacy analysis will be performed in the intention-to-treat population. An interim analysis using a two-stage sequential design with the O'Brien-Fleming method will be applied.

ETHICS AND DISSEMINATION

The trial was registered in the European Union drug regulating authorities' clinical trials database (EUDRACT) (2021-001726-22) and received approval from the local Research Ethics Committee (21/728) and the Spanish Agency of Medicines and Medical Devices (AEMPS). AEMPS classified the study as a low-intervention trial. The study will be conducted in compliance with the principles of Good Clinical Practice. The study results will be disseminated through workshops and national/international conferences and published in peer-reviewed journals. In addition, they will be disclosed to patients and the public in understandable language through study newsletters and press releases to news and social media.

PROTOCOL VERSION

V.1.1, 18 May 2023.

TRIAL REGISTRATION NUMBERS

EUDRACT 2021-001726-22 and NCT05774236.

The Correct Indication to Induce Labour in a Swiss Cantonal Hospital

BACKGROUND

Induction of labour (IOL) is a way to stimulate the onset of labour using mechanical and pharmacological methods. IOL is one of the most frequently performed obstetric procedures worldwide. We aimed to determine compliance with guidelines and to investigate factors associated with the success of labour.

METHODS

In this retrospective, observational study, we analysed all induced deliveries in a Swiss hospital between January 2020 and December 2022.

RESULTS

Out of 1705 deliveries, 349 women underwent IOL, and 278 were included in this study, with an average age of 32 years (range 19-44 years). Most of the women were induced for missed deadlines (20.1%), the premature rupture of membranes (16.5%), and gestational diabetes mellitus (9.3%), and there was a good adherence to the guideline, especially with the indication and IOL monitoring (100%). However, an improvement needs to be made in measuring and documenting the Bishop score (41%). The success of labour was associated with multiparity (81.8% vs. 62.4% p = 0.001) and maternal non-obesity (73.4 vs. 54.1% p = 0.026).

CONCLUSIONS

An improvement is needed in the measurement and documentation of the Bishop score. Further research is needed to confirm the found associations between parity, obesity, and the success of IOL.

Assessing uterine electrophysiology prior to elective term induction of labor

Objective

The purpose of this study was to determine if uterine electrophysiological signals gathered from 151 non-invasive biomagnetic sensors spread over the abdomen were associated with successful induction of labor (IOL).

Study design

Uterine magnetomyogram (MMG) signals were collected using the SARA (SQUID Array for Reproductive Assessment) device from 33 subjects between 37 and 42 weeks gestational age. The signals were post-processed, uterine contractile related MMG bursts were detected, and parameters in the time and frequency domain were extracted. The modified Bishop score calculated at admission was used to determine the method of IOL. Wilcoxon's rank-sum test was used to compare IOL successes and failures for differences in gestational age (GA), parity, modified Bishop's score, maximum oxytocin, and electrophysiological parameters extracted from MMG.

Results

The average parity was three times (3x) higher (1.53 versus 0.50; p = 0.039), and the average modified Bishop score was 2x higher (3.32 versus 1.63; p = 0.032) amongst IOL successes than failures, while the average GA and maximum oxytocin showed a small difference. For the MMG parameters, successful IOLs had, on average, 3.5x greater mean power during bursts (0.246 versus 0.070; p = 0.034) and approximately 1.2x greater mean number of bursts (2.05 versus 1.68; p = 0.036) compared to the failed IOLs, but non-significant differences were observed in mean peak frequency, mean burst duration, and mean duration between bursts.

Conclusion

The study showed that inductions of labor that took less than 24 h to deliver have a higher mean power in the baseline electrophysiological activity of the uterus when recorded prior to planned induction. The results are indicative that baseline electrophysiological activity measured prior to induction is associated with successful induction.

Failed Induction of Labor and Associated Factors Among Women Who Undergone Induction of Labor in Jimma Medical Center, Ethiopia: A Hospital-Based Cross-Sectional Study

BACKGROUND

Although induction of labor is intended to achieve a safe vaginal delivery, its process is not always successful. Failed induction of labor leads to an increased risk of complication for both mother and fetus. Thus, this study aimed to assess the proportion of failed induction of labor and associated factors among women who undergone induction of labor from September 1, 2019 to August 31, 2020 in Jimma Medical Center (JMC), southwest Ethiopia.

METHODS

A hospital-based retrospective cross-sectional study was conducted on 243 charts of women who had induction of labor in JMC selected by a simple random sampling method from January 10 to 30, 2021. The collected data were entered into Epi-data version 4.2 and analyzed by SPSS version 23. Bivariate and multivariable logistic regression analyses were done to test the association. Adjusted odds ratio at 95% confidence interval (CI) andP-value <.05 was used to ascertain statistical significance.

RESULTS

The proportion of failed induction of labor in JMC was 16.9%. Maternal age ≥ 30 years (AOR 7.57; 95%CI = 2.88, 19.9) at (P-value = .000), elective induction (AOR .39; 95% CI = .16, .98) at (P-value = .045), and unfavorable bishop score (AOR 6.94; 95%CI = 2.35, 20.4) at (P-value = .000) were factors statistically significantly associated with failed induction of labor.

CONCLUSIONS

The proportion of failed induction of labor was relatively low in the study area. Advanced maternal age, elective induction, and unfavorable bishop score were associated with failed induction of labor. Thus, the hospital should strictly follow the protocol for induction of labor, and candidates of emergency induction of labor should be counseled thoroughly so as to be well prepared psychologically for the labor thereby reducing the risk of failed induction.

Failed induction of labor and associated factors among women undergoing induction at University of Gondar Specialized Hospital, Northwest Ethiopia

BACKGROUND

Induction of labor is a process of artificially initiating labor to attain vaginal birth. Despite its vital role in the reduction of maternal mortality, the failure rate of induction and its contributing factors were not well studied in Ethiopia; particularly there was a limited study in the study area. This study aimed to assess the prevalence and factors associated with failed induction of labor among women undergoing induction at University of Gondar Specialized Hospital, Northwest Ethiopia.

METHODS

An institution-based retrospective cross-sectional study was conducted among 743 women undergoing induction at University of Gondar Specialized Hospital. A systematic random sampling method was used to draw a sample and the data were retrieved from the maternity registration books and medical records. Data were cleaned and entered into EpiData version 3.1 and SPSS version 20 used for analysis. Frequencies, proportions, and summary statistics were used to describe the study population and a multivariable logistic regression model was fitted to identify factors contributing to failed induction of labor. Odds ratio with 95% confidence interval computed and level of significance declared at P-value< 5%.

RESULTS

The prevalence of failed induction of labor was 24.4% (95% CI: 21.4, 27.9). Age ≤ 30 years (AOR = 3.7, 95% CI: 2.2,6.2), rural residence (AOR = 3.7, 95% CI: 2.4,5.8), being nulliparous (AOR = 2.1, 95% CI: 1.2,3.7), 5 or less Bishop Score (AOR = 3.4, 95% CI: 2.2,5.4), premature rupture of membrane (AOR = 2.7, 95% CI: 1.5,4.6), having pregnancy-induced hypertension (AOR = 4.0, 95% CI: 2.3,7.1), and artificial rupture of membrane with oxytocin (AOR = 0.2, 95% CI: 0.1, 0.4) were associated with failed induction of labor.

CONCLUSIONS

One-fourth of women undergoing induction at University of Gondar Specialized Hospital had failed induction of labor. Age, residence, parity, bishop score, premature-rupture of the membrane, pregnancy-induced hypertension, and method of induction were independent predictors for failed induction of labor. The combination method of ARM with oxytocin, early detection and treatment of pregnancy-induced hypertension and premature rupture of the membrane are highly recommended for reducing failed induction of labor.

Predicting cesarean delivery for failure to progress as an outcome of labor induction in term singleton pregnancy

BACKGROUND

Induction of labor is one of the most common interventions in modern obstetrics, and its frequency is expected to continue to increase. There is inconsistency as to how failed induction of labor is defined; however, the majority of studies define success as the achievement of vaginal delivery. Induction of labor in nulliparous women poses an additional challenge with a 15% to 20% incidence of failure, ending in emergency operative deliveries. The Bishop score has been traditionally used before decisions for induction of labor. Nonetheless, it is subjective and prone to marked interobserver variation. Several studies have been conducted to find alternative predictors, yet a reliable, objective method still remains to be introduced and validated. Hence, there is still a need for the development of new predictive tools to facilitate informed decision making, optimization of resources, and minimization of potential risks of failure. Furthermore, a peripartum transperineal ultrasound scan has been proven to provide objective, noninvasive assessment of labor.

OBJECTIVE

This study aimed to assess the feasibility of developing and validating an objective and reproducible model for the prediction of cesarean delivery for failure to progress as an outcome of labor induction in term singleton pregnancies.

STUDY DESIGN

This was a prospective observational cohort study conducted in Cairo University Hospitals and University of Bologna Hospitals between November 2018 and November 2019. We recruited 382 primigravidae with singleton term pregnancies in cephalic presentation. All patients had baseline Bishop scoring together with various transabdominal and transperineal ultrasound assessments of the fetus, maternal cervix, and pelvic floor. The managing obstetricians were blinded to the ultrasound scan findings. The method and indication of induction of labor, the total duration of stages of labor, mode of birth, and neonatal outcomes were all recorded. Women who had operative delivery for fetal distress or indications other than failure to progress in labor were excluded from the final analysis, leaving a total of 344 participants who were randomly divided into 243 and 101 pregnancies that constituted the model development and cross-validation groups, respectively.

RESULTS

It was possible to perform transabdominal and transperineal scans and assess all the required parameters on all study participants. Univariate and multivariate analyses were used for selection of potential predictors and model fitting. The independent predictive variables for cesarean delivery included maternal age (odds ratio, 1.12; P=.003), cervical length (odds ratio, 1.08; P=.04), angle of progression at rest (odds ratio, 0.9; P=.001), and occiput posterior position (odds ratio, 5.7; P=.006). We tested the performance of the prediction model on our cross-validation group. The calculated areas under the curve for the ability of the model to predict cesarean delivery were 0.7969 (95% confidence interval, 0.71-0.87) and 0.88 (95% confidence interval, 0.79-0.97) for the developed and validated models, respectively.

CONCLUSION

Maternal age and sonographic fetal occiput position, angle of progression at rest, and cervical length before labor induction are very good predictors of induction outcome in nulliparous women at term.

Induction of labor using Foley catheter with weight attached versus without weight attached: A randomized control trial

OBJECTIVE

To assess the effectiveness in preventing cesarean section for failed induction by using Foley catheter for cervical ripening in comparison to Foley catheter with a weight attached to it.

METHODS

A randomized control trial conducted between November 2018 and July 2020, which looked at induction of labor with 30-ml Foley catheter in one arm and the Foley placed with a 500 ml weight attached to it in the other arm. Primary outcome was the cesarean section rate.

RESULTS

We randomized 399 women. Modes of delivery were similar in both groups. Numbers undergoing cesarean section for failed induction were higher in the group that underwent induction with Foley with weight but this was not statistically significant (45.7% vs 26.5%, P = 0.1). There was a shorter time to expulsion of the Foley with weight attached (mean ± standard deviation: 2.6 ± 3.3 h vs 10.9 ± 3.2 h, P < 0.001) but this did not translate into a difference in time to active labor or time to delivery.

CONCLUSION

Placing a weight at the end of the Foley catheter for induction of labor does not affect the time to delivery or the rate of cesarean deliveries, although there is faster expulsion of the Foley. Clinical trial registration no.: CTRI/2018/10/016154.

Recent advances in the induction of labor

The rate of labor induction is steadily increasing and, in industrialized countries, approximately one out of four pregnant women has their labor induced. Induction of labor should be considered when the benefits of prompt vaginal delivery outweigh the maternal and/or fetal risks of waiting for the spontaneous onset of labor. However, this procedure is not free of risks, which include an increase in operative vaginal or caesarean delivery and excessive uterine activity with risk of fetal heart rate abnormalities. A search for "Induction of Labor" retrieves more than 18,000 citations from 1844 to the present day. The aim of this review is to summarize the controversies concerning the indications, the methods, and the tools for evaluating the success of the procedure, with an emphasis on the scientific evidence behind each.

Effect of extra-amniotic Foley's catheter and vaginal misoprostol versus vaginal misoprostol alone on cervical ripening and induction of labor in Kenya, a randomized controlled trial

BACKGROUND

The safest, most effective and fastest combined approaches to induction of labor is unknown. In an open-label randomized clinical trial we evaluated the efficacy of combination of extra-amniotic Foley's catheter and vaginal misoprostol compared to vaginal misoprostol alone for cervical ripening and induction of labor on the incidence of failed induction, induction-to-delivery interval and adverse maternal and perinatal outcomes.

METHODS

Pregnant women at gestational age of 28 weeks or greater admitted at Kenyatta National Hospital, Kenya for induction of labor were enrolled then randomized to either a combination of extra-amniotic Foley's catheter inflated by 30 cm3 of normal saline and 25 micrograms of vaginal misoprostol or 25 micrograms of vaginal misoprostol alone. Women underwent 6 hourly reviews and additional misoprostol inserted if required. The primary outcome was incidence of failed induction. Secondary outcomes were induction-to-delivery interval and adverse maternal and perinatal outcomes. We conducted an intent-to-treat analysis and compared means or medians using t-test or Wilcoxon rank, proportions using Chi-square or Fishers test as appropriate. Induction-to-delivery interval were compared using the log-rank test. P-values of < 0.05 and 95% confidence intervals that excluded the null were considered statistically significant.

RESULTS

Between February and May 2016, we enrolled 180 of 237 pregnant women admitted for induction of labor and randomized them to either a combination of extra-amniotic Foley's catheter and vaginal misoprostol (n = 90) or vaginal misoprostol alone (n = 90). The socio-demographic and obstetric characteristics were similar between the two groups. Failed induction rates were lower but not statistically significant following combined extra-amniotic Foley's catheter and vaginal misoprostol (8.9%) versus vaginal misoprostol alone (11.1%). The mean induction-to-delivery time was 4.8 h shorter in the combined extra-amniotic Foley's catheter and vaginal misoprostol (mean 18.9, standard deviation (SD) 7.2 h) compared to misoprostol only group (mean 14.1, SD 6.9 h) (log-rank test, p < 0.001). Maternal and perinatal complications were similar between the two groups.

CONCLUSIONS

Extra-amniotic Foley's catheter and vaginal misoprostol for cervical ripening and induction of labor did not significantly lower the incidence of failed induction but safely shortened induction-to-delivery time compared to vaginal misoprostol only.

TRIAL REGISTRATION

Trial was retrospectively registered on 14-03-2016 PACTR201604001535825.

Outcome of Induction and Associated Factors among Term and Post-Term Mothers Managed at Jimma University Specialized Hospital: A Two Years' Retrospective Analysis

BACKGROUND

Induction of labor using oxytocin is a routine procedure in obstetrics used for vaginal delivery of gravid uterus. The purpose of this study was to analyze outcome of induction with oxytocin and associated factors among mothers who delivered at term and post-term in Jimma University Specialized Hospital, Southwest Ethiopia.

METHODS

A facility based cross-sectional study was conducted on records of 280 laboring mothers who delivered at term and post-term after induction with oxytocin from September 1(st), 2009 to August 31(st), 2011. The data were extracted using checklist and analyzed using SPSS windows version 16.0. The level of significance to declare relationship between the dependent and independent variables was set at p< 0.05.

RESULTS

Mean maximum oxytocin levels used until vaginal delivery and at time of diagnosis of failed induction were 55.0 ± 29.8 and 89.7± 11.6 miu/min respectively. Mean time elapsed from initiation of induction with oxytocin to vaginal delivery and till diagnosis of failed induction were 6:10 ± 3:09 and 9:57± 2:01 hours respectively. Failed induction was diagnosed in 21.4% of the mothers. Primigravidity, unfavorable and intermediate Bishop Scores determined at admission were found to be predictors of failed induction.

CONCLUSION

High rate of failed induction and high level of oxytocin use were found. Preparation of the cervix before commencing induction in primigravid women is recommended to improve success of induction with the current protocol.

Maternal and perinatal outcomes in women with and without hypertensive syndromes submitted to induction of labor with misoprostol

OBJECTIVES

To determine maternal and perinatal outcomes according to the mode of delivery in normotensive and hypertensive women bearing a live, full-term fetus, who were submitted to labor induction with misoprostol.

METHODS

Retrospective cohort study. The endpoints were tachysystole, uterine hyperstimulation, indications for cesarean section, severe maternal morbidity, side effects, maternal death, 1st/5th minute Apgar, neonatal death, requirement for neonatal intensive care, and birth weight (grams). The chi-square or Fisher's exact test was applied at a significance level of 5%. Risk ratios (RRs) and their 95% confidence intervals (95% CI) were calculated.

RESULTS

No significant differences were found in maternal outcome as a function of mode of delivery. First-minute Apgar score <7 was less common with vaginal deliveries in normotensive women (RR = 0.41; 95% CI: 0.18-0.90), this being the only significant difference in perinatal outcome.

CONCLUSION

Maternal and perinatal outcomes were similar in hypertensive and normotensive women submitted to labor induction with misoprostol.

Failed induction of labor

Induction of labor will affect almost a quarter of all pregnancies, but historically there has been no generally accepted definition of failed induction of labor. Only recently have studies analyzed the lengths of latent labor that are associated with successful labor induction ending in a vaginal delivery, and recommendations for uniformity in the diagnosis of failed induction have largely resulted from this data. This review assesses the most recent and inclusive definition for failed induction, risk factors associated with failure, complications, and special populations that may be at risk for a failed induction.

Definition of Failed Induction of Labor and Its Predictive Factors: Two Unsolved Issues of an Everyday Clinical Situation

OBJECTIVE

The objectives of this review were to identify the predictive factors of induction of labor (IOL) failure or success as well as to highlight the current heterogeneity regarding the definition and diagnosis of failed IOL.

MATERIALS AND METHODS

Only studies in which the main or secondary outcome was failed IOL, defined as not entering the active phase of labor after 24 h of prostaglandin administration ± 12 h of oxytocin infusion, were included in the review. The data collected were: study design, definition of failed IOL, induction method, IOL indications, failed IOL rate, cesarean section because of failed IOL and predictors of failed IOL.

RESULTS

The database search detected 507 publications. The main reason for exclusion was that the primary or secondary outcomes were not the predetermined definition of failed IOL (not achieving active phase of labor). Finally, 7 studies were eligible. The main predictive factors identified in the review were cervical status, evaluated by the Bishop score or cervical length.

DISCUSSION

Failed IOL should be defined as the inability to achieve the active phase of labor, considering that the definition of IOL is to enter the active phase of labor. A universal definition of failed IOL is an essential requisite to analyze and obtain solid results and conclusions on this issue. An important finding of this review is that only 7 of all the studies reviewed assessed achieving the active phase of labor as a primary or secondary IOL outcome. Another conclusion is that cervical status remains the most important predictor of IOL outcome, although the value of the parameters explored up to now is limited. To find or develop predictive tools to identify those women exposed to IOL who may not reach the active phase of labor is crucial to minimize the risks and costs associated with IOL failure while opening a great opportunity for investigation. Therefore, other predictive tools should be studied in order to improve IOL outcome in terms of health and economic burden.

[Double-balloon device and intravaginal dinoprostone for cervical ripening in women with unfavourable cervix]

OBJECTIVES

To compare the efficiency of a double cervical ripening (mechanical agent and dinoprostone) to a dinoprostone-only ripening in women with an unfavourable cervix.

METHODS

In a retrospective study from January 2008 to October 2013, 96 patients were included with the following criteria: pregnancies over 37 weeks, singleton, vertex presentation, medical indication for induction of labor, no premature rupture of membranes and very unfavourable cervix (Bishop score ≤ 3). Patients were classified into 2 groups: intravaginal dinoprostone for 24h (prostaglandin group, n=38) and double-balloon device for 12h followed by intravaginal dinoprostone for 24h (balloon+prostaglandin group, n=58).

RESULTS

There was no difference in vaginal delivery rates between the 2 groups (balloon+prostaglandin group 51.7%, prostaglandin group 50%, P=0.87). The Bishop score after cervical ripening was significantly higher in the balloon+prostaglandin group (4.4 versus 2.4, P<0.0001), but the interval between the induction and the delivery was longer (33.6h versus 24.9h, P=0.0044). There was no significant difference for maternal and neonatal complications.

CONCLUSION

A double cervical ripening (with mechanical agent and dinoprostone) allows the Bishop score to be improved without increasing the rate of vaginal delivery, for patients with a Bishop score ≤ 3.

[Cervical ripening: is there an advantage for a double-balloon device in labor induction?]

OBJECTIVES

To compare efficiency of a double-balloon to vaginal prostaglandins for cervical ripening in patients with unfavourable cervix.

PATIENTS AND METHODS

Fifty patients induced with a double-balloon were compared to 50 patients receiving vaginal prostaglandins. Matching criteria were age, parity, history of uterine scar, gestational age and Bishop score. The primary outcome was failure induction. Secondary outcomes included improvement in Bishop score, ripening-to-delivery interval, caesarean section rate, maternal and neonatal morbidity.

RESULTS

Risk of failed induction (16% in the double-balloon group vs. 14% in the prostaglandins group) and caesarean section rate (28% vs. 36%) were similar in the two groups. The proportion of favourable cervix and the time to obtain a better Bishop score were similar with the two methods. Maximal pain score during cervical ripening was significantly lower in the double-balloon group (P<0.001). Ripening-to-delivery interval (30.4 h ± 15.6h vs. 28.9 h ± 20.5h) was not different between the two groups. There was no difference about maternal and neonatal outcomes.

DISCUSSION AND CONCLUSION

The double-balloon was as efficient as vaginal prostaglandins. The ripening-to-delivery interval was not different between the two groups. The main advantage of this device could be a better tolerance favourishing patient satisfaction.

Interinstitutional variation of caesarean delivery rates according to indications in selected obstetric populations: a prospective multicenter study

The aim of the study was to identify which groups of women contribute to interinstitutional variation of caesarean delivery (CD) rates and which are the reasons for this variation. In this regard, 15,726 deliveries from 11 regional centers were evaluated using the 10-group classification system. Standardized indications for CD in each group were used. Spearman's correlation coefficient was used to calculate (1) relationship between institutional CD rates and relative sizes/CD rates in each of the ten groups/centers; (2) correlation between institutional CD rates and indications for CD in each of the ten groups/centers. Overall CD rates correlated with both CD rates in spontaneous and induced labouring nulliparous women with a single cephalic pregnancy at term (P = 0.005). Variation of CD rates was also dependent on relative size and CD rates in multiparous women with previous CD, single cephalic pregnancy at term (P < 0.001). As for the indications, "cardiotocographic anomalies" and "failure to progress" in the group of nulliparous women in spontaneous labour and "one previous CD" in multiparous women previous CD correlated significantly with institutional CD rates (P = 0.021, P = 0.005, and P < 0.001, resp.). These results supported the conclusion that only selected indications in specific obstetric groups accounted for interinstitutional variation of CD rates.

Risk of caesarean section after induced labour: do hospitals make a difference?

Background

There is a well-known relationship between induced labour and caesarean rates. However, it remains unknown whether this relationship reflects the impact of more complex obstetric conditions or the variability in obstetric practices. We sought to quantify the independent role of the hospital as a variable that can influence the occurrence of caesarean section after induced labour.

Methods

As part of the Portuguese Generation XXI birth cohort, we evaluated 2041 consecutive women who underwent singleton pregnancies with labour induction, at five public level III obstetric units (April 2005-August 2006). The indications for induction were classified according to the guidelines of the American and the Royal Colleges of Obstetricians and Gynaecologists. Poisson regression models were adjusted to estimate the association between the hospital and surgical delivery after induction. Crude and adjusted prevalence ratios (PR) and a 95% confidence interval (95% CI) were computed.

Results

The proportion of women who were induced without formal clinical indications varied among hospitals from 20.3% to 45.5% (p < 0.001). After adjusting for confounders, the risk of undergoing a caesarean section after induced labour remained significantly different between the hospitals, for the cases in which there was no evident indication for induction [the highest PR reaching 1.86 (95% CI, 1.23–2.82)] and also when at least one such indication was present [1.53 (95% CI, 1.12–2.10)]. This pattern was also observed among the primiparous cephalic term induced women [the highest PR reaching 2.06 (95% CI, 1.23–2.82) when there was no evident indication for induction and 1.61 (95% CI, 1.11–2.34) when at least one such indication was present].

Conclusions

Caesarean section after induced labour varied significantly across hospitals where similar outcomes were expected. The effect was more evident when the induction was not based on the unequivocal presence of commonly accepted indications.

Failed induction of labor: strategies to improve the success rates

The rates of induction of labor (IOL) are rising all over the world. In developed countries, one of every 4 babies is born after IOL at term. The recent World Health Organization guidelines on IOL recommend that failure of induction does not necessitate cesarean delivery [WHO recommendations for induction of labor. World Health Organization, 2011]. These guidelines come when there are concerns that failed primary inductions in nulliparous women, which have led to escalation of the cesarean delivery rates. Obstetricians must recognize the risks associated with IOL (including failure and need for cesarean delivery) and avoid inductions for borderline indications, which are not evidence based. The issue of "failed induction of labor" is topical, and there is a need to define this entity and offer alternatives to cesarean delivery in the management of this group of women. Research is required to develop a test to accurately identify those fetuses most at risk of morbidity or stillbirth who would truly benefit from an early IOL and assess the cost-effectiveness of policies of routine IOL. In this review, we summarized the current recommendations for best practice in the area of IOL, defined "failed induction," and described options to improve the success rate after "failed primary induction of labor."

TARGET AUDIENCE

Obstetricians & Gynecologists and Family Physicians.

LEARNING OBJECTIVES

After the completing the CME activity, physicians should be better able to classify the factors determining success or failure of induction of labor, counsel women about risks and benefits of various methods of induction of labor, and compare the options of management available after failed primary induction of labor.

Induction of labour with vaginal prostaglandin tablet vs gel

The objective of this study was to compare outcomes in women whose labour was induced with vaginal prostaglandin E2 tablets with those induced with prostaglandin gel. We compared outcomes of induction during two audits conducted in 2005 (PGE2 gel) and 2009 (PGE2 tablets). We found that there was no difference in induction rates; 21% in 2005 and 24% in 2009. The recommended dose of prostaglandin E2 was exceeded in 6% and 17% of women induced with gel and tablets, respectively (p=0.007). There was a difference in use of syntocinon to augment uterine contractions, 39% vs 58% for women induced with gel and tablets, respectively (p=0.001). There was no difference in overall operative delivery, 37% in gel and 38% in tablets. There was no difference in the proportion of women who had vaginal birth within 24 h; 50% vs 42% for gel and tablet, respectively (p=0.187). We conclude that compared to prostaglandin gel, women who received prostaglandin tablets were more likely to require syntocinon to augment contractions.

A Review of Factors Associated With Dystocia and Cesarean Section in Nulliparous Women

The primary indication for cesarean section in nulliparous women continues to be clinical diagnoses that fall under the rubric of dystocia. These diagnoses account for approximately two-thirds of all cesareans experienced by otherwise healthy nulliparous women. Contemporary research evidence suggests that this clinical phenomenon is complex and multifactorial. This review explores factors associated with the phenomenon of dystocia in the context of a conceptual model that considers women's physical and psychological characteristics, fetal factors, intrapartum care and interventions, assessments and clinical decision-making of health care providers, the sociopolitical environment, and the social and physical environment of childbirth. Clinical recommendations include emphasis on the maintenance of normal weight and weight gain during pregnancy, delaying the admission of nulliparous women to the hospital until active labor is established, avoiding elective induction for nulliparous women, keeping women well-hydrated and well-fed during labor, providing high-quality supportive care during labor, staying the course with effective treatment when dystocia is encountered, and a renewed emphasis on the psychobehavioral preparation of nulliparous women for the realities of labor.

Contemporary patterns of spontaneous labor with normal neonatal outcomes

OBJECTIVE

To use contemporary labor data to examine the labor patterns in a large, modern obstetric population in the United States.

METHODS

Data were from the Consortium on Safe Labor, a multicenter retrospective study that abstracted detailed labor and delivery information from electronic medical records in 19 hospitals across the United States. A total of 62,415 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor, stratified by cervical dilation at admission and centimeter by centimeter.

RESULTS

Labor may take more than 6 hours to progress from 4 to 5 cm and more than 3 hours to progress from 5 to 6 cm of dilation. Nulliparous and multiparous women appeared to progress at a similar pace before 6 cm. However, after 6 cm, labor accelerated much faster in multiparous than in nulliparous women. The 95 percentiles of the second stage of labor in nulliparous women with and without epidural analgesia were 3.6 and 2.8 hours, respectively. A partogram for nulliparous women is proposed.

CONCLUSION

In a large, contemporary population, the rate of cervical dilation accelerated after 6 cm, and progress from 4 cm to 6 cm was far slower than previously described. Allowing labor to continue for a longer period before 6 cm of cervical dilation may reduce the rate of intrapartum and subsequent repeat cesarean deliveries in the United States.

Is induced labour in the nullipara associated with more maternal and perinatal morbidity?

PURPOSE

To ascertain any differences in foetomaternal outcomes in induced and spontaneous labour among nulliparous women delivering at term.

METHODS

A retrospective matched cohort study consisting of 403 nulliparous women induced at ≥ 292 days and 806 nulliparous women with spontaneous labour at 285-291 days.

RESULTS

Compared to those in spontaneous labour, women who had induction of labour were three times more likely to have a caesarean delivery (OR 3.1, 95% CI 2.4-4.1; P < 0.001). Women who had induction of labour were 2.2 times more likely to have oxytocin augmentation (OR 2.2, 95% CI 1.7-2.8; P < 0.001), 3.6 times more likely to have epidural anaesthesia (OR 3.6, 95% CI 2.8-4.6; P < 0.001), 1.7 times more likely to have uterine hyperstimulation (OR 1.7, 95% CI 1.1-2.6), 2 times more likely to have a suspicious foetal heart rate trace (OR 2.0, 95% CI 1.5-2.6), 4.1 times more likely to have blood loss over 500 ml (OR 4.1, 95% CI 2.9-5.5; P < 0.001), and 2.9 times more likely to stay in hospital beyond 5 days (OR 2.9, 95% CI 1.5-5.6; P < 0.001). Babies born to mothers who had induction of labour were significantly more likely to have an Apgar score of <5 at 5 min and an arterial cord pH of <7.0.

CONCLUSION

Compared to those with spontaneous labour, nulliparous women with induced labours are more likely to have uterine hyperstimulation, caesarean delivery, and babies with low Apgar scores. Nulliparous women should be made aware of this, as well as potential risks of expectant management during counseling.

The natural history of the normal first stage of labor

OBJECTIVE

To examine labor patterns in a large population and to explore an alternative approach for diagnosing abnormal labor progression.

METHODS

Data from the National Collaborative Perinatal Project were used. A total of 26,838 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor stratified by cervical dilation at admission and centimeter by centimeter.

RESULTS

The median time needed to progress from one centimeter to the next became shorter as labor advanced (eg, from 1.2 hours at 3-4 cm to 0.4 hours at 7-8 cm in nulliparas). Nulliparous women had the longest and most gradual labor curve; multiparous women of different parities had very similar curves. Nulliparas may start the active phase after 5 cm of cervical dilation and may not necessarily have a clear active phase characterized by precipitous dilation. The deceleration phase in the late active phase of labor may be an artifact in many cases.

CONCLUSION

The active phase of labor may not start until 5 cm of cervical dilation in multiparas and even later in nulliparas. A 2-hour threshold for diagnosing labor arrest may be too short before 6 cm of dilation, whereas a 4-hour limit may be too long after 6 cm. Given that cervical dilation accelerates as labor advances, a graduated approach based on levels of cervical dilation to diagnose labor protraction and arrest is proposed.

LEVEL OF EVIDENCE

III.

Cesarean delivery for abnormal labor

Cesarean delivery is indicated at any stage in the labor process in the presence of nonreassuring fetal status or when conservative measures fail in the setting of abnormal labor. In the absence of maternal or fetal indications for expedited delivery, cesarean delivery is not indicated for latent phase disorders. When to intervene for protracted labor is arguable, but slow rates of labor progress are consistent with safe vaginal delivery. Cesarean delivery in the second stage should be avoided for at least 4 hours if there is progressive fetal descent.