Can we predict successful cervical ripening with prostaglandin E2 vaginal inserts?

External validation and updating of the Rossi nomogram for predicting cesarean delivery following induction: is the Bishop score valuable?

OBJECTIVE

This study sought to validate the Rossi nomogram in a Chinese population and then to include the Bishop score to see if it has an effect on the accuracy of the nomogram.

MATERIALS AND METHODS

The Rossi predictive model was applied and externally validated in a retrospective cohort from August 2017 and July 2023 in a Chinese tertiary-level medical center. For the revision and updating of the models, the regression coefficients of all the predictors (except race) were re-estimated and then the cervical Bishop score at the time of induction was added. Each model's performance was measured using the receiver-operating characteristic and calibration plots. Decision curve analysis determined the range of the probability threshold for each prediction model that would be of clinical value.

RESULTS

A total of 721 women met the inclusion criteria, of whom 183 (25.4%) underwent a cesarean delivery. The calibration demonstrated the underestimation of the original model, with an area under the curve (AUC) of 0.789 (95% confidence interval [CI] 0.753-0.825, p < 0.001). After recalibrating the original model, the discriminative performance was improved from 0.789 to 0.803. Moreover, the discriminatory power of the updated model was further improved when the Bishop score at the time of induction was added to the recalibrated multivariable model. Indeed, the updated model demonstrated good calibration and discriminatory power, with an AUC of 0.811. The decision curve analysis indicated that all the models (original, recalibrated, and updated) provided higher net benefits of between 0 and 60% of the probability threshold, which indicates the benefits of using the models to make decisions concerning patients who fall within the identified range of the probability threshold. The net benefits of the updated model were higher than those of the original model and the recalibrated model.

CONCLUSION

The nomogram used to predict cesarean delivery following induction developed by Rossi et al. has been validated in a Chinese population in this study. More specifically, adaptation to a Chinese population by excluding ethnicity and including the Bishop score prior to induction gave rise to better performance. The three models (original, recalibrated, and updated) offer higher net benefits when the probability threshold is between 0 and 60%.

Predictive Factors for the Success of Vaginal Dinoprostone for the Induction of Labour

Objective

To evaluate factors predictive of the success of a slow-release dinoprostone vaginal insert for cervical ripening.

Methods

This retrospective study included 187 women who received dinoprostone vaginal inserts for cervical ripening. The participants were divided into two groups: the transvaginal delivery group (n = 87) and cesarean section termination group (n = 100). The correlation between the parameters present before cervical ripening with dinoprostone slow release and its success, as well as complications and adverse outcomes, was analyzed. Cesarean section predictors and area under the curve (AUC) were compared between the two Groups.

Results

There were statistical differences between the two groups in body mass index (BMI), height, cervical Bishop score, cephalic position, time of medication use, and fetal head position at the time of medication use (P<0.05). The optimal thresholds for identifying cesarean section in dinoprostone vaginal insert for cervical ripening were 162.5 for height (AUC = 0.61), 10.65 cm for amniotic fluid index (AUC = 0.6), S-2.5 for cephalic position (AUC = 0.61), 5.5 for bishop score of cervix (AUC = 0.65). The height, amniotic fluid index, cephalic position, and Bishop score of the cervix were included in the same model. The AUC value of the combined model was higher than the AUC value of the single factor.

Conclusion

The combined model was a better predictor of cesarean section in dinoprostone vaginal inserts for cervical ripening and labor induction. The success of cervical ripening with a dinoprostone slow-release vaginal insert can be predicted by the factors that can be recognized at admission.

Prediction of an effective cervical ripenning in the induction of labour using vaginal dinoprostone

To develop a predictive model for successful cervical ripening in women that undergo induction of labour by means of a vaginal prostaglandin slow-release delivery system (Propess®).  Prospective observational study on 204 women that required induction of labour between February 2019 and May 2020 at "La Mancha Centro" hospital in Alcázar de San Juan, Spain. The main variable studied was effective cervical ripening (Bishop score > 6). Using multivariate analysis and binary logistic regression, we created three initial predictive models (model A: Bishop Score + Ultrasound cervical length + clinical variables (estimated fetal weight, premature rupture of membranes and body mass index)); model B: Ultrasound cervical lenght + clinical variables; and model C: Bishop score + clinical variables) to predict effective cervical ripening. All three predictive models obtained (A, B and C) presented good predictive capabilities, with an area under the ROC curve ≥ 0.76. Predictive model C, composed of the variables: gestational age (OR 1.55, 95% CI 1.18-2.03, p = 0.002), premature rupture of membranes (OR 3.21 95% CI 1.34-7.70, p = 0.09) body mass index (OR 0.93, 95% CI 0.87-0.98, p = 0.012), estimated fetal weight (OR 0.99, 95% CI 0.99-1.00, p = 0.068) and Bishop score (OR 1.49 95% CI 1.18-1.81, p = 0.001), is presented as the model of choice with an area under the ROC curve of 0.76 (95% CI 0.70-0.83, p < 0.001). A predictive model composed of the variables: gestational age, premature rupture of membranes, body mass index, estimated fetal weight and Bishop score upon admission presents good capabilities in predicting successful cervical ripening following administration of prostaglandins. This tool could be useful in making clinical decisions with regard to induction of labour.

Prediction of successful labor induction in persons with a low Bishop score using machine learning: Secondary analysis of two randomized controlled trials

BACKGROUND

The objective of this paper was to identify predictors of a vaginal birth in individuals with singleton pregnancies and a Bishop Score <4, following Induction of Labor (IoL) using dinoprostone vaginal insert (DVI). Secondarily, we sought to understand the association between oxytocin use for labor augmentation and IoL outcomes.

METHODS

We developed and internally validated a multivariate prediction model using machine learning (ML) applied to data from two Phase-III randomized controlled double-blind trials (NCT01127581, NCT00308711). The model was internally validated using 10-fold cross-validation.

RESULTS

This study included 1107 participants. Despite unfavorable cervical status and inclusion of high-risk pregnancies, 72% of participants had vaginal births. The model's area under receiver operating characteristic curve was 0.73. The following factors increased the chance of vaginal birth: being parous; being between 37 and 41 weeks of gestation; having a lower Body Mass Index; having a lower maternal age; having fewer maternal comorbidities; and having a higher Bishop score. Parity alone correctly predicted the outcome in ~50% of cases, at a ~10% false-negative rate. Participants whose labors progressed without requiring oxytocin had a higher probability of vaginal birth than those requiring oxytocin for either induction or augmentation (81% vs 70% vs 77%, respectively).

DISCUSSION

Even in high-risk pregnancies and with low Bishop scores, the use of DVI results in a high chance of vaginal birth. Parity is a critical predictor of success. The judicious use of oxytocin for labor induction or augmentation can increase the chance of vaginal birth. Our study validates the use of ML and predictive modeling for treatment response prediction when considering IoL.

Labour induction in twin pregnancies

Medically-indicated deliveries are common in twin pregnancies given the increased risk of various obstetric complications in twin compared to singleton pregnancies, mainly hypertensive disorders of pregnancy and foetal growth restriction. Due to the unique characteristics of twin pregnancies, the success rates and safety of labour induction may be different than in singleton pregnancies. However, while there are abundant data regarding induction of labour in singleton pregnancies, the efficacy and safety of labour induction in twin pregnancies have been far less studied. In the current manuscript we summarize available data on various aspects of labour induction in twin pregnancies including incidence, success rate, prognostic factors, safety and methods for labour induction in twins. This information may assist healthcare providers in counselling patients with twin pregnancies when labour induction is indicated.

The efficacy and safety of second dinoprostone pessary or balloon catheter after unsuccessful primary ripening with dinoprostone pessary

We investigated which treatment should be applied if primary cervical ripening with a dinoprostone pessary is unsuccessful. We included 281 women who experienced unsuccessful cervical ripening with a dinoprostone pessary and continued on induction of labour (IOL). Of the 281 women recruited, 177 were given a second dose of dinoprostone; 104 women received a balloon catheter. The second dinoprostone pessary was successful in achieving vaginal delivery in 88 of the 177 (48.6%) women, while the balloon catheter was successful in 42 of the 104 women (40.4%); there was no significant difference between the two treatments with regards to successful vaginal delivery. However, of the women who experienced successful vaginal delivery, the delivery rate in the dinoprostone group was significantly higher than that in the balloon catheter group 12, 24, 36, or 48 h after insertion (p = .0094, .0005, .0258, .0483, respectively). The neonatal outcomes, the proportion of maternal infection and postpartum haemorrhage were similar between the two groups.IMPACT STATEMENTWhat is already known on this subject? Labour induction is a common procedure in obstetrics in a bid to achieve vaginal delivery in China, because vaginal delivery is more beneficial and associated with a better quality of life as compared to a Caesarean delivery. There is consensus relating to the preferred method of IOL after unsuccessful IOL with a dinoprostone pessary.What do the results of this study add? This is the first study in a Chinese population to compare the dinoprostone pessary and balloon catheter for women with no response to dinoprostone for cervical ripening with a sample size greater than 100. We found that a second dose of dinoprostone can reduce the time from the re-initiation of IOL to vaginal delivery compared with the balloon catheter. Our data also indicated that all other outcomes relating to the mother and infant were similar.What are the implications of these findings for clinical practice and/or future research? A second dose of dinoprostone is a superior choice for women who experience unsuccessful IOL with dinoprostone to further accelerate vaginal delivery.

The effect of evening primrose oil on labor induction and cervical ripening: A systematic review and meta-analysis

The evening primrose oil has prostaglandin effects and is applied to soften the cervix. This systematic review and meta-analysis aimed to establish the results of clinical trials performed on the effect of evening primrose oil on labor induction and cervical ripening in pregnant women. Research studies were searched from 1990 to September 2019 in Pubmed, Science Direct, Embase, and Cochrane Library using the keywords: cervical ripening, Bishop score, labor induction, post-term pregnancy, evening primrose, and any possible combination of these keywords (Farsi, English). Data analysis was conducted using STATA (version 14.1), and I² index and random effect forest plots to assess the heterogeneity between the studies and perform the meta-analysis, respectively. Six articles that met the inclusion criteria were extracted in which four were entered into quantitative meta-analysis. The results' high heterogeneity was 91.4% based on I² index (p ≤ .001) and the random model was applied for meta-analysis. The result demonstrated no significant difference between the intervention and control groups in terms of mean difference of the Bishop score before and after intervention (SMD: 0.27, 95%CI: -0.41, 0.96, p = .43). Based on current meta-analysis on four studies, effectiveness of oral consumption of evening primrose on cervical ripening was not approved.

Repeated dose of prostaglandin E2 vaginal insert when the first dose fails

Objective

To compare the obstetric and neonatal outcomes of patients treated with repeated-dose prostaglandin E2 (dinoprostone) vaginal insert when the first dose fails.

Materials and Methods

This retrospective study included 1.043 pregnant women who received dinoprostone for labor induction between November 2012 and August 2015. Pregnant women were divided into two groups according to the number of dinoprostone administrations: group 1, single-dose dinoprostone (n=1.000), and group 2, repeated-dose dinoprostone (n=43). Intrapartum, postpartum, and neonatal outcomes of the pregnant women were compared.

Results

Vaginal delivery rate was 65% in group 1 and 30.2% in group 2 (p=0.001). The need for the neonatal intensive care unit was found in 44 pregnant women (4.4%) in group 1 and 6 pregnant women (13.6%) in group 2 (p=0.006).

Conclusion

When obstetric and neonatal data were evaluated in our study, we observed that dinoprostone administration was associated with increased cesarean rates and adverse neonatal outcomes with repeated-dose dinoprostone when the first dose failed.

Retrospective Comparison of PGE2 Vaginal Insert and Foley Catheter for Outpatient Cervical Ripening

OBJECTIVE

To compare the efficacy of two methods of outpatient cervical ripening (CR): an intracervical Foley catheter and a prostaglandin E₂ (PGE)₂ slow-release vaginal insert.

METHODS

All records of women receiving outpatient CR at a tertiary care hospital from January 2017 to June 2018 were retrospectively reviewed. We compared time from insertion of first CR agent until delivery between groups using a Cox proportional hazards (CPH) model. Exclusion criteria included age <18 years, multiple gestation, or contraindication to either CR method. Secondary outcomes included time from removal of agent and time from admission until delivery, additional CR used, uterine tachysystole, labour and delivery complications, type of delivery, and adverse neonatal outcomes.

RESULTS

A total of 153 patients were included (82 Foley; 71 PGE₂). Baseline characteristics were comparable except for lower dilation in the PGE₂ group (16% vs. 38% <1cm dilated; P < 0.05). In the CPH model, time from insertion to delivery was not different between PGE₂ and Foley catheter groups (median 27 vs. 33 h), controlling for parity, gestational age, initial dilation, and use of oxytocin (HR 1.13, 95% confidence interval 0.77-1.68). Patients in the PGE₂ group were more likely to experience uterine tachysystole (9% vs. 0%; P < 0.01) and require another method of CR (34% vs. 1%; P < 0.001). There were no differences in neonatal or maternal adverse outcomes between groups.

CONCLUSION

Our results suggest that outpatient Foley catheter and PGE₂ CR are comparable in time from insertion to delivery; however, PGE₂ inserts are associated with higher rates of tachysystole and the need for second CR method. A prospective study is warranted to further investigate these findings.

Comparison of two management options for labor induction following unsuccessful prostaglandin E2 ripening

Objective: We sought to compare the likelihood of a vaginal delivery (VD) using oxytocin, with and without a cervical ripening balloon, in nulliparous women who did not respond to initial ripening with prostaglandin E2 (PGE2).Methods: We a performed a retrospective cohort study of nulliparous women with a singleton pregnancy at term who underwent cervical ripening with vaginal PGE2 between October 2015 and March 2019. Patients who did not respond to PGE2 ripening (bishop score (BS) of 6 or less with cervical dilation less than 3 cm) were stratified into two groups based on management: sequential ripening with a cervical ripening balloon in addition to oxytocin versus oxytocin alone. Patients who had PGE2 for less than 6 h, a BS greater than 6 after ripening, rupture of membranes or missing data were excluded. The primary outcome was VD. Secondary outcomes included VD within 24 h of induction, time from induction to delivery, rates of chorioamnionitis and postpartum hemorrhage, presence of meconium, neonatal birthweight, NICU admission, 5 min apgar < 5, and umbilical cord pH < 7. Statistical analysis included Chi-squared, Fisher's exact and Mann-Whitney U tests, as well as logistic regression. Odds ratios (ORs) were calculated and adjusted for significant confounders using backwards-stepwise logistic regression. For time to delivery, a Cox proportional hazard regression was used to determine the hazard ratio (HR) and adjusted HR.Results: 840 patients underwent cervical ripening with PGE2 during the study period. After the exclusion criteria were applied, 272 cases comprised the study cohort. Of those, 123 (45%) continued labor induction with a cervical ripening balloon and oxytocin and 149 (55%) continued labor induction with oxytocin alone. Baseline characteristics such as age, BMI, ethnicity, gestational age at induction and number of women undergoing elective induction were similar between both groups. There was no statistically significant difference in the likelihood of VD (oxytocin and cervical ripening balloon: 62.6% vs. oxytocin alone: 50.3%; a OR 1.61, p = .07) or rate of secondary outcomes between the two groups. Patients in the oxytocin alone group had a higher BS after PGE2 ripening, although both were very low (3 vs. 2, p < .0001).". Additionally, there were significantly more patients undergoing full PGE2 ripening for 12 h in the cervical ripening balloon and oxytocin group compared to oxytocin alone (65.9% vs. 49.7%, p = .02).Conclusion: Our data did not show a difference in VD rate in nulliparous women unresponsive to PGE2 ripening who underwent continued induction with oxytocin and cervical ripening balloon compared to oxytocin alone. Larger studies investigating the utility of sequential ripening and determining the optimal induction method following unsuccessful ripening are needed.

Predictor variables in the success of slow-release dinoprostone used for cervical ripening in intrauterine growth restriction pregnancies

OBJECTIVE

This study aims to evaluate the consequences of a trigger by vaginal Dinoprotone on outcome of pregnancies with Intrauterine growth restriction (IUGR).

MATERIALS AND METHODS

This retrospective study included 161 induced IUGR fetuses (35-39 weeks). Consecutive patients who were evaluated formed the basis of the clinical outcomes. The penalized maximum likelihood estimation (PMLE) method was used instead of traditional logistic regression in order to reduce the risk of overfitting.

RESULTS

Of the 25,678 deliveries that occurred during the study period, 161 (0.6%) women underwent IUGR delivery; of these, 117 (73%) succeeded and 44 (27%) failed to achieve cervical ripening using the dinoprostone slow-release vaginal insert. Two predictors were associated with dinoprostone vaginal delivery success: Parity (OR:1.4([0.89-2.3]), and Bishop score (OR:1.54[1.23-1.94]). The PMLE model correctly classified 78% participants (c-index: 0.78).

CONCLUSION

Basic parameters such as parity and Bishop score can be used to predict successful vaginal birth following dinoprostone slow-release vaginal insert administration.

Ultrasound examination of the cervix for predicting labor induction success: failed validation in a routine clinical setting of a successful previous pilot study

BACKGROUND

Induction of labor (IL) involves an overload of work in hospitals, as well as increased intervention. Traditionally, the Bishop score (BS) has been used to predict the outcome of a IL, but there is a growing interest in studying the predictive capacity of ultrasound variables.

OBJECTIVE

Validate a pilot predictive model performed by a single observer (Alvarez-Colomo C), based on clinical parameters and ultrasound parameters, that showed a significant association with the IL result, obtaining a correct prediction of vaginal delivery in 82.8%, with 15% false positive (FP). This validation was carried out under the usual conditions of clinical practice by four observers without distinction.

METHODS

A prospective, observational study was conducted between September 2010-July 2012, recruiting 231 single pregnancies (Group 2), who were to initiate the IL process, according to the methodology and inclusion criteria of the Alvarez-Colomo study (Group 1151 patients). The outcome variable was the method of delivery.

RESULTS

Only fetal head-perineal distance (FHPD), cervical length (CL) and BS showed significant association with the result of IL. After applying the logistic regression equation of the pilot study, the model developed by these four observers reached a predictive capacity of 70.74% (FP = 20%). Clinical characteristics were similar in both groups. Statistically significant differences were found between the two groups for: FHPD, posterior cervical angle (PCA) and funnel existence.

CONCLUSION

It has not been possible to validate the mathematical model of Alvarez's study in the daily conditions of clinical practice, probably due to differences in the ultrasound measurement of FHPD.

Prediction models for determining the success of labor induction: A systematic review

INTRODUCTION

The purpose of this study was to systematically identify and compare clinical models using universally accessible clinical and demographic factors that were derived and/or validated to predict the success of labor induction with a view to making recommendations for practice.

MATERIAL AND METHODS

MEDLINE, Embase, www.clinicaltrials.gov, and PubMed (for non-MEDLINE and studies in-progress) were searched from inception to November 2017. Only studies that derived and/or validated clinical prediction models using variables obtained through antenatal history and digital cervical examination were included. Two reviewers independently screened titles and abstracts and extracted data from eligible studies into a standardized form. Extracted data included: participant characteristics, sample size, variables considered and included, endpoint definitions, study design and model performance. The Prediction Study Risk of Bias Assessment Tool (PROBAST) was used to appraise included studies. In view of clinical and methodologic heterogeneity between studies, only descriptive analysis was possible. The protocol was registered with the PROSPERO International prospective register of systematic reviews [CRD42017081548].

RESULTS

The search identified 16 studies describing 14 prediction models derived between 1966 and 2018. Models varied and demonstrated major limitations with regard to methodology, scope and performance. Of the derived models, six were internally validated and three were externally validated. Performance was most commonly measured using the area under the receiver operator characteristic curve, which ranged from 0.68 to 0.79, 0.67 to 0.77 and 0.61 to 0.73 for derived, internally validated and externally validated models, respectively. The risk-of-bias of included studies ranged from some studies fulfilling only 36% and some others fulfilling 86% of eligible PROBAST items.

CONCLUSIONS

No published model can be recommended for use at the bedside to determine the success of vaginal birth after labor induction. Based on the limitations of included models, a list of recommendations for improving model performance and utilization is provided, as well as measures for encouraging appropriate use of prediction models. The attitudes of women and care providers, and the clinical and resource implications must be explored prior to recommending the use of prediction models for determining the success of labor induction.

Prediction of the efficacy of dinoprostone slow release vaginal insert (Propess) for cervical ripening: A prospective cohort study

AIM

To evaluate factors predictive of the success of dinoprostone slow release vaginal insert for cervical ripening.

METHODS

A total of 169 women who underwent cervical ripening with dinoprostone slow release vaginal insert were included in the study cohort. The correlation between parameters present before cervical ripening with dinoprostone slow release and its success, as well as complications and adverse outcomes were analyzed.

RESULTS

Dinoprostone slow release vaginal insert was successful in achieving vaginal delivery in 148 of 169 (87.6%), while sufficient ripening was achieved in 140 (83%) cases. Factors associated with successful vaginal delivery were multiparity and younger gestational age at delivery. Factors predictive of the success of cervical ripening with dinoprostone slow release vaginal insert were lower body mass index (BMI), higher parity and perceived contractions prior to insertion. Intrauterine growth restriction was associated with a significant risk for dinoprostone insert removal. Neonatal outcomes were similar in cases of successful or failed ripening.

CONCLUSION

The success of cervical ripening with dinoprostone slow release vaginal insert can be predicted by factors that can be recognized at admission.

Application effect of single balloon catheters in labor induction of pregnant women in late-term pregnancy and their influences on stress and inflammatory responses

This study was designed to evaluate the application effect of single balloon catheters and dinoprostone on promoting cervical ripening of pregnant women in late-term pregnancy and their influences on stress and inflammatory responses. A total of 160 pregnant women with indications of labor induction were included and randomly divided into the control (n=80) and observation (n=80) groups. Patients in the control group received labor induction by administration of dinoprostone at the vaginal vault, while those in the observation group received labor induction by domestic single balloon catheters. Cervical ripening (Bishop score), means of pregnancy, the total stage of labor, maternal and child complications, and Apgar scores of newborn infants at 1 min after delivery between the two groups were compared. At the prenatal and postpartum 12, 24 and 48 h, the levels of cortisol (COR), norepinephrine (NE) and β-endorphin (β-EP), were detected using radioimmunoassay, and those of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured using enzyme-linked immunosorbent assay (ELISA). Cervical Bishop scores in the two groups after intervention were significantly higher than those before intervention, and the score of the observation group was significantly higher than that of the control group. The difference was statistically significant (P<0.05). In the observation group, the total stage of labor was significantly shortened, the Apgar score of the newborn infant at 1 min after delivery was increased compared with those in the control group, and the differences were statistically significant (P<0.05). The delivery rate of cesarean section in the observation group was lower than that in the control group, the overall incidence rate of perinatal complications was decreased, and the differences were statistically significant (P<0.05). The levels of stress and inflammatory response markers at 12 h after delivery in the two groups reached the peak, and then declined (P<0.05). The levels of stress and inflammatory response markers at each time-point after delivery in the observation group were significantly lower than those in the control group, and the difference was statistically significant (P<0.05). The results showed that the single balloon catheter promotes cervical ripening, improves pregnancy outcomes and reduces the stress and inflammatory responses of pregnant women in late-term pregnancy, and is better than dinoprostone and has better application and promotion values.