The Bishop Score as a determinant of labour induction success: a systematic review and meta-analysis

Labor Induction Outcomes with Outpatient Misoprostol for Cervical Ripening among Low-Risk Women

OBJECTIVE

 In 2012, two Kaiser Permanente Northern California (KPNC) hospitals began offering outpatient cervical ripening with oral misoprostol under a study protocol. We evaluated inpatient time from admission to delivery and adverse maternal and neonatal outcomes associated with outpatient use of misoprostol for cervical ripening among low-risk women with term pregnancies.

STUDY DESIGN

 We conducted a retrospective cohort study comparing three groups: women who received misoprostol (1) outpatient, under a study protocol; (2) inpatient, at the study sites; and (3) inpatient, at all KPNC hospitals. Data were obtained from between 2012 and 2017. The primary outcome was time from inpatient admission to delivery. Secondarily, we evaluated maternal and neonatal outcomes, including the duration and maximum rate of oxytocin administered, rate of cesarean delivery, incidence of chorioamnionitis and blood transfusion, Apgar scores, and neonatal intensive care unit admissions. Demographic and clinical characteristics and outcomes of the outpatient group were compared with both inpatient misoprostol groups using the appropriate statistical test. Variables included in the regression analysis were either statistically significant in the bivariate analyses or have been reported in the literature to be potential confounders: maternal age at admission, race/ethnicity, body mass index, cervical dilation at initial misoprostol, and parity.

RESULTS

 We analyzed data from 10,253 patients: (1) 345 outpatients, under a study protocol; (2) 1,374 inpatients, at the study sites; and (3) 9,908 inpatients, at all the Kaiser hospitals. Women in the outpatient group were more likely to be white than both inpatient groups (63.3 vs. 56.3% at study sites and 47.1% in all hospitals, p = 0.002 and <0.001, respectively); other demographics were clinically comparable. Most women undergoing labor induction were nulliparous; however, a greater proportion in the outpatient group were nulliparous compared with inpatient groups (70.8 vs. 61.8% and 64.3%, p = 0.002 and 0.01). On inpatient admission for delivery, women who received outpatient misoprostol were more likely to have a cervical dilation of ≥3 cm (39.8 vs. 12.5% at study sites and 9.7% at all KPNC hospitals, p < 0.001 for both). The outpatient group had a shorter mean time between admission and delivery (23.6 vs. 29.4 at study sites and 29.8 hours at all KPNC, p < 0.001 for both). The adjusted estimated mean difference between the outpatient and inpatient group at all the Kaiser hospitals in time from admission to delivery was -6.48 hours (p < 0.001), and the adjusted estimated mean difference in cervical dilation on admission was +1.02 cm (p < 0.001). There was no difference in cesarean delivery rates between groups. The rate of chorioamnionitis in the outpatient group was higher compared with inpatients at all hospitals (17.7 vs. 10.6%, p < 0.001), but similar when compared with the inpatients at the study sites (17.7 vs. 15.4%, p = 0.29).

CONCLUSION

 Outpatient use of misoprostol for cervical ripening under the study protocol was associated with reduced inpatient time from admission to delivery compared with inpatient misoprostol. Although there was a higher rate of chorioamnionitis among outpatients under the study protocol compared with inpatients at all hospitals, there was no difference when compared with inpatients at the study sites. There was no difference in rates of cesarean delivery or maternal or neonatal complications with outpatient misoprostol.

KEY POINTS

· Outpatient misoprostol patients had 6.46 fewer hours from admission to delivery compared with inpatients at all hospitals.. · There was no difference in the rate of cesareans between the outpatient versus inpatient misoprostol groups.. · Other maternal and neonatal complications were low and comparable among outpatients and inpatients who received misoprostol; this study was not large enough to assess rare safety outcomes..

Comparative study of second-line labor induction methods in patients with unfavorable cervix after first-line low-dose oral misoprostol

OBJECTIVE

The present study aimed to evaluate low-dose oral misoprostol induction, and compare different methods used in second-line induction in patients with a Bishop score less than 6.

METHODS

This retrospective study analyzed the medical history and courses of pregnancy of all patients induced with first-line of low-dose oral misoprostol (50 μg every 4 h with a total of 200 μg/24 h) from April 2021 to June 2022 in a university hospital center, and reported outcomes according to the second-line method of induction.

RESULTS

Among 437 labor inductions with low-dose oral misoprostol, 120 patients required a second-line induction. Predictive factors of first-line failure were higher body mass index (P = 0.011), absence of premature rupture of membranes (P = 0.021) and earlier term of pregnancy (P < 0.001). Regarding second methods of induction of labor, time from induction to delivery was shorter in the oxytocin group than the dinoprostone and misoprostol groups (24.0 vs. 41 and 51.0 h, respectively; P < 0.001), and was also significantly shorter in the dinoprostone than the misoprostol group (P = 0.048). Cesarean section rates did not differ between the three groups (P = 0.651). There were no clinically significant differences in adverse events between the groups.

CONCLUSION

Normal body mass index, previous rupture of membranes and later term of induction of labor were the three favoring success factors during first-line oral misoprostol. In cases of a Bishop score <6, oxytocin may be the best option to reduce duration to delivery, with the same maternal-fetal outcomes, including a similar rate of vaginal delivery.

The Use of Evening Primrose Oil for Cervical Ripening in Low-Risk Women with Term Pregnancy: A Randomized Double-Blinded Controlled Trial

BACKGROUND

Several methods have been developed for cervical ripening. The data regarding the efficiency of evening primrose oil (EPO) are inconsistent. The purpose of this study was to investigate the outcomes of EPO use on cervical ripening in low-risk women with term pregnancy.

PATIENTS AND METHODS

Low-risk term pregnant women referred to the obstetrics clinic of Imam Hossein Hospital in Tehran who were eligible according to the inclusion were randomized either to the case or control group. The case group received 1,000 mg vaginal EPO capsule, and the other group received a vaginal placebo capsule daily, similar to the original drug. The primary outcome was Bishop score, while the duration of labor phases and the inducing procedures were the secondary outcomes.

RESULTS

Forty-eight participants were randomized to each group and were considered for data analysis. Although Bishop score was not statistically different before the intervention, it was significantly higher in case group compared to the placebo group after the intervention (EPO = 5.83 ± 1.68, placebo = 5.19 ± 1.52, p value = 0.002). Four participants in the case group and two in the control group underwent cesarean section (p value = 0.677). The need for labor induction was significantly higher in the placebo group than EPO group (oxytocin injection: 10.4% vs. 31.3%, p value = 0.012, amniotomy: 75% vs. 41.7, p value = 0.001).

CONCLUSION

The vaginal use of EPO could be considered as a safe and efficient approach for cervical ripening in low-risk term pregnant women.

Hintergrund

Es wurden verschiedene Methoden zur Zervixreifung entwickelt. Die Daten zur Wirksamkeit von Nachtkerzenöl (evening primrose oil, EPO) sind uneinheitlich. Mit dieser Studie sollen die Ergebnisse der Anwendung von EPO zur Zervixreifung bei Frauen mit niedrigem Risiko und termingerechter Schwangerschaft untersucht werden.

Patientinnen und Methoden

Schwangere Frauen mit niedrigem Risiko und termingerechter Schwangerschaft, die in die Geburtsklinik des Imam-Hossein-Krankenhauses in Teheran eingewiesen wurden und gemäss den Einschlusskriterien für die Teilnahme infrage kamen, wurden randomisiert der Fall- oder der Kontrollgruppe zugewiesen. Die Fallgruppe erhielt 1.000 mg EPO als Vaginalkapseln, während die andere Gruppe täglich eine vaginale Placebokapsel erhielt, die dem Originalpräparat ähnelte. Primäres Zielkriterium war der Bishop-Score und sekundäre Zielkriterien waren die Dauer der Wehenphasen sowie die Verfahren zur Geburtseinleitung.

Ergebnisse

Jeder Gruppe wurden randomisiert 48 Teilnehmerinnen zugewiesen und bei der Datenanalyse berücksichtigt. Während vor der Intervention kein statistisch signifikanter Unterschied im Bishop-Score bestand, fiel dieser nach der Intervention in der Fallgruppe signifikant höher aus als in der Placebogruppe (EPO = 5,83 ± 1,68, Placebo = 5,19 ± 1,52, p-Wert = 0,002). Bei vier Teilnehmerinnen in der Fallgruppe und zwei in der Kontrollgruppe wurde ein Kaiserschnitt durchgeführt (p-Wert = 0,677). Die Notwendigkeit einer Weheneinleitung war in der Placebogruppe signifikant höher als in der EPO-Gruppe (Oxytocin-Injektion: 10,4% vs. 31,3%, p-Wert = 0,012, Amniotomie: 75% vs. 41,7%, p-Wert = 0,001).

Schlussfolgerung

Die vaginale Anwendung von EPO kann als sicherer und wirksamer Ansatz zur Zervixreifung bei Frauen mit niedrigem Risiko und termingerechter Schwangerschaft angesehen werden.

Fetal heart rate patterns and the incidence of adverse events after oral misoprostol administration for cervical ripening among low-risk pregnancies

OBJECTIVE

Though misoprostol is commonly used for inpatient cervical ripening, its use in outpatient settings has been limited by safety concerns. This study was conducted to assess the association between early fetal heart tracing (FHT) and maternal tocodynamometry patterns and the incidence of adverse fetal and pregnancy outcomes after the administration of oral misoprostol for cervical ripening.

METHODS

We conducted a retrospective cohort study of 9908 low-risk patients at ≥37 weeks gestation who received oral misoprostol for cervical ripening prior to rupture of membranes between 01/01/2012 and 12/31/2017 at Kaiser Permanente Northern California hospitals as inpatients. We excluded patients who received a different agent for cervical ripening or had any need for additional inpatient monitoring, including hypertensive disorders of pregnancy, diabetes, or intrauterine growth restriction. Abnormal FHT, abnormal uterine activity, and adverse pregnancy or fetal-related events documented in the electronic health record in the four hours after administration of the first and second doses of misoprostol were assessed using descriptive statistics.

RESULTS

We found that 0.9% of patients experienced tachysystole after the first dose of misoprostol (0.6% without decelerations; 0.3% with decelerations). The incidence of variable decelerations only and other FHT abnormalities (i.e. bradycardia, late or prolonged decelerations, or absent or minimal variability) in the first hour after misoprostol administration were 7.1% and 6.7% respectively, and diminished over time. The need for tocolytic use was 0.2% in the first hour and declined over time to 0.03% in the fourth hour after the first dose. Urgent cesarean delivery occurred in 0.1% of patients after receiving the first dose of misoprostol. Patients who did not experience variable, prolonged, or late decelerations in the first hour after the initial misoprostol dose were less likely to have such FHT abnormalities in the subsequent three hours compared to patients who had other FHT abnormalities (11.8% among patients with no FHT abnormalities vs. 43.7% among patients with other FHT abnormalities; p <.001). The overall trends in outcomes over time were similar after the second dose of misoprostol.

CONCLUSION

The risk of short-term adverse outcomes associated with misoprostol is low among relatively low-risk patients. FHT abnormalities occurred in up to 32% of patients in the first four hours of monitoring post-misoprostol. Patients with no FHT abnormalities in the first hour after receiving misoprostol had a low risk of developing adverse outcomes and FHT abnormalities on continued monitoring, while patients with any type of deceleration in the first hour were at higher risk of adverse outcomes and FHT abnormalities. Our data may inform the development of protocols for cervical ripening that allow reduced monitoring for a subset of low-risk patients, however, more research is needed to validate findings and develop clinical protocols.

An evaluation of cervical maturity for Chinese women with labor induction by machine learning and ultrasound images

BACKGROUND

To evaluate the improvement of evaluation accuracy of cervical maturity for Chinese women with labor induction by adding objective ultrasound data and machine learning models to the existing traditional Bishop method.

METHODS

The machine learning model was trained and tested using 101 sets of data from pregnant women who were examined and had their delivery in Peking University Third Hospital in between December 2019 and January 2021. The inputs of the model included cervical length, Bishop score, angle, age, induced labor time, measurement time (MT), measurement time to induced labor time (MTILT), method of induced labor, and primiparity/multiparity. The output of the model is the predicted time from induced labor to labor. Our experiments analyzed the effectiveness of three machine learning models: XGBoost, CatBoost and RF(Random forest). we consider the root-mean-squared error (RMSE) and the mean absolute error (MAE) as the criterion to evaluate the accuracy of the model. Difference was compared using t-test on RMSE between the machine learning model and the traditional Bishop score.

RESULTS

The mean absolute error of the prediction result of Bishop scoring method was 19.45 h, and the RMSE was 24.56 h. The prediction error of machine learning model was lower than the Bishop score method. Among the three machine learning models, the MAE of the model with the best prediction effect was 13.49 h and the RMSE was 16.98 h. After selection of feature the prediction accuracy of the XGBoost and RF was slightly improved. After feature selection and artificially removing the Bishop score, the prediction accuracy of the three models decreased slightly. The best model was XGBoost (p = 0.0017). The p-value of the other two models was < 0.01.

CONCLUSION

In the evaluation of cervical maturity, the results of machine learning method are more objective and significantly accurate compared with the traditional Bishop scoring method. The machine learning method is a better predictor of cervical maturity than the traditional Bishop method.

Repeatability and Reproducibility of Potential Ultrasonographic Bishop Score Parameters

Determination of the Bishop score (BS) is a traditional method of assessing the cervix in obstetrics and gynecology. This examination is characterized by subjectivity of assessment and low repeatability. In scientific studies intended to evaluate the results of the procedure based on the initial assessment, it is necessary to find an objective scale based on ultrasonography. We selected five ultrasound parameters, measured with a transvaginal transducer, that are equivalent to the individual BS axes (dilatation assessed in three-dimensional ultrasound (DL), angle of progression (AoP), vagino-cervical angle (VCA), strain elastography using the E-Cervix module, and cervical length (CL)). All selected parameters were characterized by good to excellent repeatability (intraclass correlation coefficient (ICC) = 0.878-0.994) and reproducibility (ICC = 0.826-0.996). Each of the selected parameters significantly correlated with its corresponding BS axis. The highest value of the correlation coefficient was achieved with CL (-0.75) and DL (0.71). Other parameters were characterized by an average to high correlation (AoP and station = 0.69, hardness ratio and consistency = -0.33, position and VCA = -0.38). The best correlation with the sum of the BS points was exhibited by AoP (0.52) and CL (-0.61). The selected ultrasound parameters analogous to the BS axes were characterized by high repeatability and significant correlation with the axes of the original clinical BS. Further research into the predictive properties of a multivariate model based on these parameters is needed.

Unexpected Uterine Rupture-A Case Report, Review of the Literature and Clinical Suggestions

BACKGROUND AND OBJECTIVES

Women with a history of cesarean section are a high-risk group because they are likely to develop uterine rupture during their next pregnancy. Current evidence suggests that a vaginal birth after cesarean section (VBAC) is associated with lower maternal mortality and morbidity than elective repeat cesarean delivery (ERCD). Additionally, research suggests that uterine rupture can occur in 0.47% of cases of trial of labor after cesarean section (TOLAC).

CASE DESCRIPTION

A healthy 32-year-old woman at 41 weeks of gestation, in her fourth pregnancy, was admitted to the hospital due to a dubious CTG record. Following this, the patient gave birth vaginally, underwent a cesarean section, and successfully underwent a VBAC. Due to her advanced gestational age and favorable cervix, the patient qualified for a trial of vaginal labor (TOL). During labor induction, she displayed a pathological CTG pattern and presented symptoms such as abdominal pain and heavy vaginal bleeding. Suspecting a violent uterine rupture, an emergency cesarean section was performed. The presumed diagnosis was confirmed during the procedure-a full-thickness rupture of the pregnant uterus was found. The fetus was delivered without signs of life and successfully resuscitated after 3 min. The newborn girl of weight 3150 g had an Apgar score of 0/6/8/8 at 1, 3, 5, and 10 min. The uterine wall rupture was closed with two layers of sutures. The patient was discharged 4 days after the cesarean section without significant complications, with a healthy newborn girl.

CONCLUSIONS

Uterine rupture is a rare but severe obstetric emergency and can be associated with maternal and neonatal fatal outcomes. The risk of uterine rupture during a TOLAC attempt should always be considered, even if it is a subsequent TOLAC.

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.

Mode of delivery after labor induction with vaginal dinoprostone versus oral misoprostol for women with unfavorable cervix at term

OBJECTIVE

To compare the delivery mode after labor induction with 10 mg vaginal dinoprostone insert versus oral misoprostol 50 µg/4 h for women with an unfavorable cervix.

MATERIAL AND METHODS

This is a retrospective observational study comparing the before/after introduction of oral misoprostol for labor induction, conducted at the Saint-Étienne University Hospital on a cohort of 396 women with a Bishop score <6. One hundred and twelve women (28.3%) were treated with a 10 mg vaginal dinoprostone insert versus 284 (71.7%) with oral misoprostol 50 µg/4 h. The primary outcome was the cesarean section rate.

RESULTS

Labor induction with vaginal dinoprostone was independently associated with an increased rate of cesarean sections compared to oral misoprostol (aOR = 2.44; CI95% from 1.35 to 4.40; p = 0.003). The use of vaginal dinoprostone increased the induction rate during more than 48 h (18.8% versus 9.9%; p = 0.02), and the occurrence of fetal heart rate changes (34.8% versus 21.1%; p = 0.005). The maternofetal morbidity was similar.

CONCLUSION

Labor induction with vaginal dinoprostone was independently associated with an increased rate of cesarean sections compared to oral misoprostol in women with an unfavorable cervix.

The sonopartogram

The assessment of labor progress from digital vaginal examination has remained largely unchanged for at least a century, despite the current major advances in maternal and perinatal care. Although inconsistently reproducible, the findings from digital vaginal examination are customarily plotted manually on a partogram, which is composed of a graphical representation of labor, together with maternal and fetal observations. The partogram has been developed to aid recognition of failure to labor progress and guide management-specific obstetrical intervention. In the last decade, the use of ultrasound in the delivery room has increased with the advent of more powerful, portable ultrasound machines that have become more readily available for use. Although ultrasound in intrapartum practice is predominantly used for acute management, an ultrasound-based partogram, a sonopartogram, might represent an objective tool for the graphical representation of labor. Demonstrating greater accuracy for fetal head position and more objectivity in the assessment of fetal head station, it could be considered complementary to traditional clinical assessment. The development of the sonopartogram concept would require further undertaking of serial measurements. Advocates of ultrasound will concede that its use has yet to demonstrate a difference in obstetrical and neonatal morbidity in the context of the management of labor and delivery. Taking a step beyond the descriptive graphical representation of labor progress is the question of whether a specific combination of clinical and demographic parameters might be used to inform knowledge of labor outcomes. Intrapartum cesarean deliveries and deliveries assisted by forceps and vacuum are all associated with a heightened risk of maternal and perinatal adverse outcomes. Although these outcomes cannot be precisely predicted, many known risk factors exist. Malposition and high station of the fetal head, short maternal stature, and other factors, such as caput succedaneum, are all implicated in operative delivery; however, the contribution of individual parameters based on clinical and ultrasound assessments has not been quantified. Individualized risk prediction models, including maternal characteristics and ultrasound findings, are increasingly used in women's health-for example, in preeclampsia or trisomy screening. Similarly, intrapartum cesarean delivery models have been developed with good prognostic ability in specifically selected populations. For intrapartum ultrasound to be of prognostic value, robust, externally validated prediction models for labor outcome would inform delivery management and allow shared decision-making with parents.

Lower uterine segment thickness assessed by transvaginal ultrasound before labor induction: reproducibility analysis and relationship with delivery outcome

OBJECTIVES

To evaluate the reproducibility of lower uterine segment (LUS) thickness measurement before induction of labor (IOL), and to assess the relationship between LUS thickness and IOL outcomes.

METHODS

This was a prospective cohort study of pregnant women undergoing IOL at term, conducted in a single tertiary hospital between July 2014 and February 2017. Women with a singleton pregnancy at ≥ 37 weeks' gestation, with a live fetus in cephalic presentation and a Bishop score of ≤ 6, were eligible for inclusion. Both nulliparous and parous women, and those with a previous Cesarean section (CS), were eligible. All women underwent transvaginal ultrasound assessment before IOL admission, and cervical length and LUS thickness were measured offline after delivery. Maternal and obstetric characteristics and Bishop score were recorded. The main outcome was the overall rate of CS after IOL, and secondary outcomes were CS for either failure to progress in the active phase of labor or failed IOL, and CS for failed IOL only. Interobserver agreement for measurement of LUS thickness between two operators was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis with the ANOVA test to evaluate systematic bias. Univariable and multivariable analysis were employed to evaluate the relationship between clinical and sonographic characteristics and IOL outcomes.

RESULTS

Of 265 women included in the analysis, 195 (73.6%) had a vaginal delivery and 70 (26.4%) required a CS after IOL. Reproducibility analysis showed excellent interobserver agreement for the measurement of LUS thickness (ICC, 0.96 (95% CI, 0.93-0.98)). On Bland-Altman analysis, the mean difference in LUS thickness between the two operators was 0.15 mm (95% limits of agreement, -1.84 to 2.14 mm), and there was no evidence of systematic bias (ANOVA test, P = 0.46). Univariable analysis showed that LUS thickness was associated significantly with overall CS (P = 0.002), CS for failure to progress in the active phase of labor or failed IOL (P = 0.03) and CS for failed IOL (P = 0.037). On multivariable logistic regression analysis, LUS thickness was an independent predictive factor for overall CS (odds ratio (OR), 1.149 (95% CI, 1.031-1.281)) and CS for failure to progress in the active phase of labor or failed IOL (OR, 1.226 (95% CI, 1.039-1.445)).

CONCLUSIONS

In women undergoing IOL at term, measurement of LUS thickness is feasible and reproducible, and is associated significantly with IOL outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Cervical ripening as an outpatient procedure in the pandemic - minimizing the inpatient days and lowering the socioeconomic costs

OBJECTIVES

With an increasing incidence of labor induction the socioeconomic costs are increasing and the burden on hospital capacities is rising. In addition, the worldwide SARS-CoV-2 pandemic asks for improvements in patient care during pregnancy and delivery while decreasing the patient-staff contact. Here, we are retrospectively analyzing and comparing a mechanical ripening device that is utilized as an outpatient procedure to misoprostol and dinoprostone as inpatient induction methods in a low risk cohort.

METHODS

This is a retrospective comparative analysis of obstetric data on patients who presented for cervical ripening and labor induction. Ninety-six patients received a mechanical ripening agent as an outpatient procedure. As a control group, we used 99 patients with oral misoprostol (PGE1) and 42 patients with vaginal dinoprostone (PGE2) for cervical ripening in an inpatient setting. Data from 2016 until 2020 were analysed.

RESULTS

Baseline characteristics showed no significant differences. Delivery modes were similar in all groups. The time period from patient admission to onset of labor was significantly shorter in the outpatient group (p<0.001): 10.9 h/0.5 days (±13.6/0.6) for osmotic dilator vs. 17.9 h/0.7 days (±13.1/0.5) for oral misoprostol vs. 21.8 h/0.8 days (±15.9/0.7) for vaginal dinoprostone. With 20.4 h/0.8 days (±14.3/0.6) the osmotic dilator group displayed significantly the shortest inpatient stay from admission to delivery (p=0.027). The patient subgroup of misoprostol had 25.7 h/1.1 days (±14.9/0.6) of inpatient stay from admission to delivery and the patient group of dinoprostone 27.5 h/1.1 days (±16.0/0.7). There were fewer hospital days in the outpatient group: 84.9 h/3.5 days vs. 88.9 h/3.7 days vs. 93.6 h/3.9 days (outpatient osmotic dilator vs. inpatient misoprostol and dinoprostone, respectively).

CONCLUSIONS

New approaches are required to decrease individual contacts between patients and staff while maintaining a high quality patient care in obstetrics. This analysis reveals that outpatient mechanical cervical ripening can be as safe and effective as inpatient cervical ripening with PGE1/PGE2, while lowering patient-staff contact and total hospital stays and therefore decreasing the socioeconomic costs.

The importance of fetal adrenal gland volume measurement in successful labor induction with oxytocin

AIM

We aimed to show the predictive value of fetal adrenal gland volume (FAGV) measurement in the success of labor induction with oxytocin.

METHODS

This is a prospective cohort study that included a total of 103 term nulliparous. Immediately after deciding to induce labor with oxytocin, the fetal right and left adrenal gland measurements were obtained.

RESULTS

Induction success was achieved in 89 of 103 (86.4%) pregnant women. In comparison of the FAGV values of failed induction labor group, the total volumes of right and left fetal adrenal glands and the fetal zone volumes (FZV) were found to be statistically significantly higher in the successful labor induction group (p < 0.001). In predicting induction success, the cut-off value of fetal adrenal gland volume (cFAGV) was set as >230.2 mm³ /kg and area under curve (AUC) value of 0.872 (95% confidence interval [CI], 0.736-1.000) for right total adrenal gland (p < 0.001). The cut-off value of cFAGV was set as >236.7 mm³ /kg and AUC value of 0.891(95%CI, 0.768-1.000) (p < 0.001) for left total adrenal gland. The cut-off value of cFAGV was set as >12.6 mm³ /kg and AUC value of 0.952 (95%CI, 0.905-0.999) for right FZV(p < 0.001). The cut-off value of cFAGV was set as >7.8 mm³ /kg and AUC value of 0.884 (95%CI, 0.752-1.000) for left FZV (p < 0.001).

CONCLUSIONS

Two-dimension ultrasonographic measurement is an easy-to-access and noninvasive method that can be integrated into the algorithms to predict the success of induction based on FAGV measurement.

Effect of Castor Oil on Cervical Ripening and Labor Induction: a systematic review and meta-analysis

Objectives

Post-term pregnancy is a condition associated with increased maternal and fetal complications. Administration of castor oil causes cervical stimulation by increasing the production of prostaglandins. We examined the effects of castor oil on cervical ripening and labor induction through a systematic review and meta-analysis.

Methods

The search process was performed to obtain relevant articles from databases including Pubmed, Cochrane library, Scopus, Science direct, SID, Iran Medex, and Google Scholar using the English keywords of cervical ripening, post-term, castor oil, labor induction, Bishop score, and pregnancy considering all possible combinations without time constraints and their Persian equivalents from national databases.

Results

A total of eight related articles from the 19 primary studies were extracted and systematically reviewed. According to a cumulative chart, the difference in the post-intervention Bishop score was statistically significant (standard mean difference [SMD] 1.64, 95% confidence interval [CI] 1.67-2.11, p = 0.001), indicating an effect of castor oil on increasing the Bishop score. In addition, the difference in labor induction was statistically significant after the intervention (odds ratio 11.67, 95% CI 3.34-40.81, p = 0.001), indicating an effect of castor oil on increasing the odds ratio of labor induction (experience of vaginal delivery).

Conclusion

This meta-analysis showed that oral administration of castor oil is effective for cervical ripening and labor induction. Midwives should closely monitor pregnant women with prolonged labor and collaborate with obstetricians to employ castor oil as a safe intervention to induce cervical ripening and labor to prevent undue caesarean surgery.

Clinical predictive factors for vaginal delivery following induction of labour among pregnant women in Jordan

Background

Induction of labour (IOL) is an important and common clinical procedure in obstetrics. In the current study, we evaluate predictors of vaginal delivery in both nulliparous and multiparous women in north Jordan who were induced with vaginal prostaglandins.

Method

A prospective study was conducted on 530 pregnant women at King Abdullah University Hospital (KAUH) in north Jordan. All pregnant mothers with singleton live fetuses, who had induction of labour (IOL) between July 2017 and June 2019, were included in the study. Mode of delivery, whether vaginal or caesarean, was the primary outcome. Several maternal and fetal variables were investigated. The safety and benefit of repeated dosage of vaginal prostaglandin E2 (PGE2) tablets, neonatal outcomes and factors that affect duration of labour were also evaluated.

Pearson χ2 test was used to investigate the significance of association between categorical variables, while student’s t-test and ANOVA were applied to examine the mean differences between categorical and numerical variables. Linear regression analysis was utilized to study the relation between two continuous variables. A multivariate regression analysis was then performed. Significance level was considered at alpha less than 0.05.

Results

Nulliparous women (N = 254) had significantly higher cesarean delivery rate (58.7% vs. 17.8%, p < 0.001) and longer duration of labour (16.1 ± 0.74 h vs. 11.0 ± 0.43 h, p < 0.001) than multiparous women (N = 276). In nulliparous women, the rate of vaginal delivery was significantly higher in women with higher Bishop score; the mean Bishop score was 3.47 ± 0.12 in nulliparous women who had vaginal delivery vs. 3.06 ± 0.10 in women who had cesarean delivery (Adjusted odds ratio (AOR) = 1.2, 95% CI: 1.03–1.28, p = 0.03). In multiparous women, the rate of vaginal delivery was significantly higher in women with higher Bishop scores and lower in women with higher body mass index (BMI). The mean Bishop score was 3.97 ± 0.07 in multiparous women who had vaginal delivery vs. 3.56 ± 0.16 in women who had cesarean delivery (AOR = 1.5, 95% CI: 1.1–2.1, p = 0.01). The mean BMI was 30.24 ± 0.28 kg/m² in multiparous women who had vaginal delivery vs. 32.36 ± 0.73 kg/m² in women who had cesarean delivery (AOR = 0.89, 95% CI: 0.84–0.96, p = 0.005). 27% of nulliparous women who received more than two PGE2 tablets and 50% of multiparous women who received more than two PGE2 tablets had vaginal delivery with no significant increase in neonatal morbidity.

Conclusion

Parity and cervical status are the main predictors of successful labour induction. Further studies are required to investigate the benefit of the use of additional doses of vaginal PGE2 above the recommended dose for IOL.

Cervical ripening after cesarean section: a prospective dual center study comparing a mechanical osmotic dilator vs. prostaglandin E2

OBJECTIVES

Worldwide, the overall cesarean section is rising. Trial of labor after cesarean (TOLAC) is an overall safe option with an immediate impact on neonatal and maternal short- and long-term health. Since the use of prostaglandins in cervical ripening is associated with an increased risk of uterine rupture, mechanical methods as balloon catheters or osmotic dilators have been suggested for cervical ripening prior to induction of labour. Here we are analyzing and comparing the VBAC rate, as well as maternal and fetal outcome in cervical ripening prior to TOLAC.

METHODS

This prospective dual center study analyses maternal and neonatal outcomes of TOLAC in women with an unfavorable cervix requiring cervical ripening agent. The prospective application of an osmotic dilator (Dilapan-S, n=104) was analysed in comparison to the retrospective application of off-label dinoprostone (n=102).

RESULTS

The overall fetal and neonatal outcome revealed no significant differences in both groups. Patients receiving cervical ripening with the osmotic dilator delivered vaginally/by ventouse in 52% of cases, compared to 53% when using dinoprostone (p=0.603). The interval between application to onset of labor was significantly higher in the osmotic dilator group (37.9 vs.20.7 h, p=<0.001). However, time from onset of labor to delivery was similar in both groups (7.93 vs. 7.44 h, p=0.758). There was one case of uterine rupture in the dinoprostone group.

CONCLUSIONS

Our data shows that the application of the osmotic dilator leads to similar outcomes in VBAC rate and time from onset of labor to delivery as well as safety in both groups compared to off-label use dinoprostone. Cervical ripening using the mechanical dilator is a viable and effective option, without the risk of uterine hyperstimulation.

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.

Role of Cervical Phosphorylated Insulin-Like Growth Factor-Binding Protein 1 (phIGFBP1) for Prediction of Successful Induction Among Primigravida with Prolonged Pregnancy

Purpose of the Study

To estimate and to compare the levels of cervical phIGFBP-1 among primigravida with prolonged pregnancy, with and without successful induction of labor (IOL).

Methods

A diagnostic study (cross-sectional study design) was conducted in our institution from November 2016 to April 2018 on 84 primigravida at ≥ 41 weeks with uncomplicated singleton pregnancy. The results were analyzed using SPSS software and receiver operating characteristics curves to determine the best cutoff using Youden Index. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive (+ LR) and negative likelihood ratio (- LR) were calculated. P value < 0.05 was considered significant. Logistic regression analysis was used to determine the predictive ability of the three markers for successful IOL.

Results

The cutoff level of phIGFBP-1, Bishop score (BS) and transvaginal cervical length (TVL) were 7.8 µg/l, 3 and 3.5 cm, respectively. The sensitivity, specificity, PPV, NPV, + LR and - LR of phIGFBP-1 (> 7.8 µg/l) were 0.87, 0.87, 0.89, 0.85, 6.76 and 0.15, respectively. Using logistic regression analysis, phIGFBP-1 was found to be the best predictor of successful IOL (OR 44.200; 95% CI 12.378-157.831, p < 0.001).

Conclusion

phIGFBP-1 is a strong independent predictor successful IOL as compared to TVL and BS in primigravida with prolonged pregnancy.

USEFULNESS OF TRANSPERINEAL VIRTUAL TOUCH QUANTIFICATION IN THE CERVIX FOR PREDICTING OUTCOME OF LABOR INDUCTION

This study aimed to explore the feasibility of transperineal virtual touch tissue quantification (VTQ) for predicting the outcome of labor induction. A total of 80 nulliparous pregnant women were included. Before labor induction, cervical length was measured by B-mode sonography, cervical stiffness was measured by VTQ, and Bishop score was assessed by vaginal examination. Subsequently, labor was induced using standard oxytocin infusion in all patients. Delivery within 24 hours after labor induction was classified as spontaneous delivery; otherwise, cesarean delivery was performed. Out of 80 participants, 48 (60%) delivered vaginally and 32 (40%) underwent cesarean delivery. The cervical length was significantly longer and the shear wave velocity (SWV) was greater in the cesarean delivery group than in the vaginal delivery group (p = 0.004 and p < 0.000, respectively). Logistic regression analysis indicated that only the mean SWV had independent predictive value for the outcome of labor induction (p = 0.011). The best diagnostic cut-off point of the mean SWV was 1.23 m/s, with a sensitivity of 93.8% and a specificity of 89.6%. Transperineal VTQ technique could predict the outcome of labor induction using oxytocin.

Management of labor after external cephalic version

OBJECTIVES

Current literature evaluating the role of induction of labor (IOL) following successful external cephalic version (ECV) attempt as compared to expectant management is limited. We aim to assess the risk of cesarean delivery in those undergoing immediate IOL following successful ECV as compared to those who were expectantly managed.

METHODS

A retrospective cohort study of successful external cephalic versions. The study group included 57 women that were induced after procedure in the lack of maternal or fetal indications for induction of labor. These women were compared to 341 expectantly managed women. Maternal and fetal characteristics and outcomes were compared.

RESULTS

Gestation age at delivery was higher among the expectant management group (401/7 vs. 384/7, median, p=0.002) as compared to the induction group. Cesarean delivery rates were similar between both groups (28 [8.2%] vs. 3 [5.3%], p=0.44). In a multivariate logistic regression analysis, only nulliparity was significantly associated with cesarean delivery (adjusted odds ratio 3.42, confidence interval 1.61-7.24, p=0.001). No correlation was found between the version-to-delivery interval and the risk for cesarean delivery.

CONCLUSIONS

Induction of labor after successful ECV was not shown to influence cesarean delivery rates. As immediate IOL may result in higher rate of early-term deliveries, and in light of the lack of clinical benefit, we advocate against elective IOL following successful ECV.

Health Related Quality of Life Post Labour Induction with Misoprostol Versus Dinoprostone At Muhimbili National Hospital in Dar Es Salaam, Tanzania: A cross Sectional Study

BACKGROUND

Labour induction using Misoprostol or Dinoprostone results to similar maternal and foetal clinical outcomes. However, the clinical outcome measures have rarely been combined with effects of interventions on patients' health related quality of life. This study aimed to assess postpartum health related quality of life of parturient after labour induction with vaginal administration of misoprostol versus dinoprostone.

METHODS

This was a comparative cross sectional study in which pregnant women who underwent labour induction with misoprostol and dinoprostone during the study period were included. Data were collected within 24 hours post-delivery using the 36 item short form health survey questionnaire which consists of 24 attributes distributed in five domains including bodily pains and physical performance three attributes each, mental health seven attributes, general health two attributes, social functioning six attributes and three attributes for labour induction satisfaction. We first estimated scores of all attributes in each domain using Likert scales and then the domain scores were converted into a 0 to 100 scales to express in percentage of total scores. Quality of life was compared in the two study groups using the independent samples T Test. Multivariate regression analysis was performed to control for marital status, gravidity, parity, baseline cervical status, time interval from induction to delivery and mode of delivery.

RESULTS

Women who received misoprostol reported better health related quality of life compared to those who received dinoprostone (mean score 92.89 vs. 87.25;P<.00). Misoprostol group had significantly higher scores in all domains of health related quality of life; reduced bodily pain (93.76 vs. 84.19;P<.00), physical performance (83.64 vs. 73.58;P<.00), mental health (96.40 vs. 93.55; P<.00), general health (93.78 vs. 90.23;P=.01), social functioning (94.81 vs. 91.25;P<.00) and satisfaction perceptions (94.96 vs. 90.71;P<.00).

CONCLUSION

Health related quality of life information is of particular value in routine care of natal and postnatal mothers. Current and updated guidelines should address the impacts of labour induction interventions on maternal health related quality of life, and encourage the use of quality of life information in provision of holistic natal and postnatal care services. Clinical trials are recommended to determine the effectiveness of labour induction with either of the two methods and address the historical adverse outcomes associated to the use of misoprostol.

Predictors of response after a second attempt of pharmacological labor induction: a retrospective study

PURPOSE

The aim of our study was to assess the outcomes of a prolonged induction carried out with a second sequential cycle of pharmacological stimulation after unsatisfactory response to a first attempt, and to highlight variables correlated with higher response rates.

METHODS

A retrospective study was carried out on 157 women who underwent a two-step labor induction by vaginal prostaglandins followed by a second cycle of prostaglandins or intravenous oxytocin. Outcomes assessed were mode of delivery and maternal and neonatal morbidity. Main variables of pregnancy and delivery were collected to identify factors predicting the mode of delivery.

RESULTS

Among 157 patients, 63 (40.1%) achieved a vaginal delivery, whereas 94 (59.9%) underwent Cesarean section, 9 women (5.7%) had postpartum hemorrhage; in 2 cases (1.3%), an Apgar score < 7 at 5 min from birth was reported. Higher risk of Cesarean section was observed with advanced maternal age (OR 1.13 for additional year, CI 1.04-1.22) and nulliparity (OR 8.84, CI 2.69-29.06), whereas the response rates were better in carriers of group B streptococcus colonization (OR 0.38, CI 0.17-0.84) and in women with favorable cervical status after the first stimulation (OR 0.81 for additional point of Bishop score, CI 0.70-0.94).

CONCLUSION

Labor induction with two cycles of pharmacological stimulation is a procedure with fairly good success rates and a low risk of maternal and neonatal complications. Factors predicting its success encompass younger age, parity, a positive recto-vaginal swab for group B streptococcus and a favorable cervix following the first cycle of stimulation.

Misoprostol administered sublingually at a dose of 12.5 μg versus vaginally at a dose of 25 μg for the induction of full-term labor: a randomized controlled trial

Background

Labor induction is defined as any procedure that stimulates uterine contractions before labor begins spontaneously. The vaginal and oral routes of administration of misoprostol are those most used for the induction of labor in routine practice, with the recommended dose being 25 μg. Nevertheless, the sublingual route may reduce the number of vaginal examinations required, increasing patient comfort and lowering the risk of maternal and fetal infection. Based on a previous systematic review, the objective of this study was to compare the frequency of tachysystole as the main outcome measure when misoprostol is administered sublingually at the dose of 12.5 μg versus vaginally at a dose of 25 μg to induce labor in a full-term pregnancy with a live fetus.

Methods

A randomized, placebo-controlled, triple-blind clinical trial was conducted at two maternity hospitals in northeastern Brazil. Two hundred patients with a full-term pregnancy, a live fetus, Bishop score ≤ 6 and an indication for induction of labor were included. Following randomization, one group received 12.5 μg misoprostol sublingually and a vaginal placebo, while the other group received a sublingual placebo and 25 μg misoprostol vaginally. The primary outcome was the frequency of tachysystole. Student’s t-test, the chi-square test of association and Fisher’s exact test were used, as appropriate. Risk ratios and their 95% confidence intervals were calculated.

Results

The frequency of tachysystole was lower in the group using 12.5 μg misoprostol sublingually compared to the group using 25 μg misoprostol vaginally (RR = 0.15; 95%CI: 0.02–0.97; p = 0.002). Failure to achieve vaginal delivery within 12 and 24 h was similar in both groups. Sublingual administration was preferred to vaginal administration by women in both groups; however, the difference was not statistically significant.

Conclusion

The effectiveness of labor induction with low-dose sublingual misoprostol was similar to that achieved with vaginal administration of the recommended dose; however, the rate of tachysystole was lower in the sublingual group, and this route of administration may prove a safe alternative.

Trial registration

Registration number: NCT01406392, ClinicalTrials.gov. Date of registration: August 1, 2011.

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.

Target populations to reduce cesarean rates after induced labor: A national population-based cohort study

INTRODUCTION

Great variations in cesarean rates after induction of labor exist and reasons for these disparities remain unclear. They may be explained by individual characteristics or obstetric practices. Ten-group classification systems have proved their utility to monitor cesarean rates in general population. We aimed to identify groups of women that account for most cesareans after induction of labor using the Nippita reproducible 10-group classification, specifically designed for induced population.

MATERIAL AND METHODS

A prospective population-based cohort study was performed in 94 French maternity units, including 3042 women undergoing induction of labor. Women were sorted according to 10 mutually exclusive groups based on parity, weeks of gestation, number of fetuses, fetal presentation and previous cesarean delivery. Relative size, cesarean delivery rate and contribution to the overall cesarean rate were described for each group. Cesarean rates were compared according to the Bishop score at the onset of labor induction. Indications for cesarean delivery were also described in the groups that contributed most to the overall cesarean rate. The MEDIP protocol was registered in ClinicalTrial (NCT02477085).

RESULTS

The overall cesarean rate was 21.0% among this population of induced women. Nulliparous women with a term singleton cephalic fetus (groups 1, 2 and 3; at 37-38, 39-40 and ≥41 weeks of gestation, respectively) accounted for two-thirds of the overall cesarean rate because they were the largest group (relative size of 10.6, 16.6 and 18.1%, respectively) and had higher cesarean rates (27.2, 30.9 and 33.0%, respectively). When the Bishop score was <6 (n = 2270/3042), cesarean delivery rates were higher (24.1 vs 10.7% if Bishop score ≥6, P < 0.01), in particular for group 1 (29.1 vs 12.5%, P = 0.02), and group 2 (33.3 vs 19.3%, P = 0.01). In groups 1, 2 and 3, which contributed most to the overall cesarean rate, a significant part of the cesareans were performed before 6 cm of cervical dilation for dystocia only (40.0, 16.7 and 17.6%, respectively).

CONCLUSIONS

Nulliparous women with a term singleton cephalic fetus and an unfavorable cervix represent the population to target for auditing induction practices. Specific actions could be implemented among this population to weigh the benefits and risks of induction and improve the management of labor induction.

Prediction of duration of labor based on biomechanical measurements of the cervix: A preliminary study

OBJECTIVE

Induction of labor is a common procedure in obstetrics. Predictability of duration of labor could facilitate planning as well as patient's satisfaction. The primary purpose of this study was to evaluate the usefulness of a new biomechanical measurement of the cervix based on the aspiration technique for predicting the duration of labor after induction.

STUDY DESIGN

This was a prospective single centre study. Inclusion criteria were term nulliparous pregnant women with an unfavourable cervix who needed an induction of labor. Digital (Bishop score), sonographic (cervical length and cervical consistency index (CCI)) as well as aspiration measurements (closure pressure) of the cervix were performed and compared to duration of labor. The technical feasibility and the acceptability of the measurements were explored.

RESULTS

There were no technical complications of the sonographic or aspiration measurements. Measuring the Bishop score was reported as most painful examination. Both the time to active phase of labor and the time to delivery is significantly correlated with the Bishop score, but not with the cervical length, CCI or closure pressure.

CONCLUSION

The new biomechanical measurement of the cervix, based on the aspiration technique, is technically feasible and acceptable. In our small cohort no correlation was found between the closure pressure and the duration of labor.

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.

Clinical factors and ultrasound parameters to predict successful vaginal delivery following labour induction

Morbidity and complications are higher with caesarean delivery after labour induction. We aimed to evaluate which maternal/neonatal pregnancy characteristics and ultrasound parameters are useful in predicting successful vaginal delivery following labour induction. In this retrospective observational study, several maternal and foetal characteristics were studied in 197 primigravidae women at 38 or more gestational weeks before induction. Multivariate analysis showed that maternal age (odds ratio [OR] 0.907, 95% confidence intervals [CI] 0.826-0.995, p = .038), term body mass index (BMI; OR 0.909, 95% CI 0.828-0.997, p = .044), and foetal engagement (OR 3.295, 95% CI 1.232-8.810, p = .017) were independent predictors for a successful vaginal delivery in an induced labour. An older maternal age, high term BMI and un-engagement were associated with a failed labour induction.IMPACT STATEMENTWhat is already known on this subject? Labour induction is being used more frequently worldwide, but it is not always easy to predict those patients who will progress to a vaginal delivery and those who will require a caesarean section. Because caesarean sections are associated with a higher mortality and morbidity in patients who have undergone a labour induction, it is important to identify the factors predictive of successful vaginal delivery after labour induction.What do the results of this study add? Multivariate analysis showed that maternal age, term BMI, and foetal engagement were independent predictors for successful vaginal delivery in an induced labour.What are the implications of these findings for clinical practice and/or further research? We found that maternal age, term body mass index and foetal engagement were important variables to consider when predicting a successful labour induction. A comprehensive assessment of these variables should be done before inducing labour to limit any unnecessary mortality and morbidity associated with a failed induction. Women should be given accurate information regarding the risks of induction based on their individual characteristics.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictors of mode of birth and duration of labour following induction using prostaglandin vaginal gel

BACKGROUND AND AIMS

Using data from a randomised controlled trial (RCT) comparing two policies of prostaglandin (PGE2) vaginal gel induction of labour (IOL) at term, this study aimed to determine: (i) demographic/clinical factors that predict IOL outcomes; and (ii) clinical characteristic(s) of women who would benefit from a policy of amniotomy once technically possible as opposed to giving more PGE2.

MATERIAL AND METHODS

Following an initial PGE2 dose, women were randomised to amniotomy or repeat-PGE2. Using RCT data, two multivariate models were developed, assessing the relationship between demographic/clinical characteristics and the outcomes of caesarean section (CS), and vaginal delivery within 24 h (VD < 24 h). Regression-equations were used to predict the likelihood of CS and VD < 24 h, varying independent predictors from the multivariate analyses.

RESULTS

Of 245 term women undergoing IOL, 90 had a CS, 155 delivered vaginally and 79 had a VD < 24 h. Controlling for confounders, nulliparity [adjusted odds ratio (aOR) = 3.71 (1.55, 8.88)] and modified Bishop's score (MBS) at first review [aOR = 0.78 (0.66, 0.92)] were independently associated with CS. Nulliparity [aOR = 0.06 (0.02, 0.15)], MBS at first review [aOR = 1.66 (1.35, 2.05)], and a policy of early amniotomy [aOR = 2.28 (1.04, 5.00)] were associated with VD < 24 h. Modelling using regression equations, and varying both MBS at first review and parity, there was no scenario where repeat PGE2 was predicted to be superior to an earlier amniotomy.

CONCLUSIONS

Following IOL using PGE2 vaginal gel at term, both parity and cervical favourability at first review are associated with CS and VD < 24 h. All combinations of parity and MBS at first review predicted fewer CS and greater likelihood of VD < 24 h with a policy of amniotomy once technically possible.

Bishop scoring: Perceived benefits of using in labour induction by Turkish midwives

It is not always possible to achieve a successful induction. Bishop scoring system is an efficient method used in determining whether the induction will be effective or not. The aim of this study was to train midwives on the benefits and use of the Bishop scoring system and to minimize the unnecessary use of induction. This study was conducted as pretest-posttest quasi-experimental design. This study was conducted in a maternity hospital in Erzurum between 01 February and 31 July 2012. In the study, the midwives received training on the use of the Bishop scoring system, and changes in their knowledge levels and application during practice of induction were then evaluated. While only 20% of midwives were using the Bishop score before the training, 56.7% started to use this tool after the training. Comparing the examinations performed on pregnant women by the midwives in the pre-induction period before and after the training, the mean of the Bishop score changed from 7.26 to 9.68 after the training. It was determined that the training could increase the knowledge levels of midwives regarding the Bishop scoring system and their attention paid to the Bishop scoring system in the practice of 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.

The role of sonographic cervical length in labor induction at term

The purpose of this study is to review the literature examining the role of ultrasound in the induction of labor. Databases including Ovid, PubMed, Web of Science, Google Scholar, and UpToDate were searched and current guidelines from the SOGC, the ACOG, the RCOG, and the RANZCOG were reviewed. Although studies have not demonstrated the superiority of cervical sonography to the Bishop score, the evidence indicates that sonography could be useful in planning induction of labor, significantly reducing the need for cervical ripening agents. A more comprehensive method integrating both sonography and digital exam may be more appropriate.

Induction of labor in women that had a previous cesarean delivery

OBJECTIVE

This study aims to evaluate factors that predict the likelihood of the success of induction of labor (IOL) in women that had a previous cesarean section (pCS).

METHODS

Pregnant women with one pCS performed more than 18 months prior were included in this retrospective observational study. Of the 242 eligible women, 234 were enrolled; 120 (51.3%) of these women delivered vaginally (VD), with the remainder receiving a repeat CS.

RESULTS

The main reasons for IOL were premature rupture of membranes (PROM) (37.1%) and post-date pregnancy (26.5%). Babies with a birth weight≥4000 g were more prevalent in women undergoing CS (21/114; 18.4%, p<0.02) and were associated with the failure of IOL. Uterine rupture during labor (1.3%) occurred in three cases. Having had a previous vaginal delivery (VD) (p=0.01), not being African (p=0.022), and receiving IOL for PROM (p=0.04) with a cervical Bishop score≥5 (p=0.015) significantly predicted the occurrence of a VD, with an 15% variance (p<0.001). An age>35 years appears to not affect the success of induction.

CONCLUSIONS

A successful IOL should be expected in Caucasian women induced for PROM with a favorable Bishop score.

Three-dimensional volumetric gray-scale uterine cervix histogram prediction of days to delivery in full term pregnancy

OBJECTIVE

Our aim was to figure out whether volumetric gray-scale histogram difference between anterior and posterior cervix can indicate the extent of cervical consistency.

METHODS

We collected data of 95 patients who were appropriate for vaginal delivery with 36th to 37th weeks of gestational age from September 2010 to October 2011 in the Department of Obstetrics and Gynecology, Korea University Ansan Hospital. Patients were excluded who had one of the followings: Cesarean section, labor induction, premature rupture of membrane. Thirty-four patients were finally enrolled. The patients underwent evaluation of the cervix through Bishop score, cervical length, cervical volume, three-dimensional (3D) cervical volumetric gray-scale histogram. The interval days from the cervix evaluation to the delivery day were counted. We compared to 3D cervical volumetric gray-scale histogram, Bishop score, cervical length, cervical volume with interval days from the evaluation of the cervix to the delivery.

RESULTS

Gray-scale histogram difference between anterior and posterior cervix was significantly correlated to days to delivery. Its correlation coefficient (R) was 0.500 (P = 0.003). The cervical length was significantly related to the days to delivery. The correlation coefficient (R) and P-value between them were 0.421 and 0.013. However, anterior lip histogram, posterior lip histogram, total cervical volume, Bishop score were not associated with days to delivery (P >0.05).

CONCLUSION

By using gray-scale histogram difference between anterior and posterior cervix and cervical length correlated with the days to delivery. These methods can be utilized to better help predict a cervical consistency.

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.

Labor induction with prostaglandin E2: characteristics of response and prediction of failure

OBJECTIVE

To characterize the response to labor induction with prostaglandin E2 (PGE2) and to identify risk factors for induction failure.

METHODS

A prospective controlled study of women admitted for labor induction with PGE2. Maternal characteristics, Bishop score and sonographic cervical length were documented at admission. The change in cervical characteristics and the emergence of uterine contractions following each application of PGE2 were analyzed.

RESULTS

Of the 88 women who were included in the study, 19 (21.6%) failed to response to PGE2. The following factors were independently associated with induction failure: nulliparity (odds ratio [OR] = 5.9, 95% confidence interval (CI): 1.2-30.2), pre-pregnancy body mass index >25 kg/m2 (OR = 5.4, 95% CI: 1.1-26.5), Bishop score <4 (OR = 2.3, 95% CI: 1.05-14.4), cervical length <25 mm (OR = 0.2, 95% CI: 0.1-0.8) and the development of uterine contractions in response to the first application of PGE2 (OR = 0.4, 95% CI: 0.1-0.93). Overall, most women required only one (60.9%) or two (85.5%) applications of PGE2 to achieve successful induction. The number of applications of PGE2 required to achieve successful induction was related to parity and cervical status at presentation.

CONCLUSIONS

Overall, most women who eventually respond to PGE2 do so following the first two applications of PGE2, and the contribution of subsequent applications is relatively small and related to cervical status at admission.