Predicting Cesarean Delivery After Induction of Labor Among Nulliparous Women at Term

Efficacy and safety of oral and vaginal administration of misoprostol for induction of labor in high-risk obese pregnant women with hypertension or diabetes mellitus

OBJECTIVE

This study aims to compare the safety and efficacy of misoprostol administered orally and vaginally in obese pregnant women at term with either gestational hypertension or diabetes.

METHODS

A total of 264 pregnant women were enrolled and categorized into two groups based on their primary condition: hypertension (134 cases) or diabetes mellitus (130 cases) and were further divided into subgroups for misoprostol administration: orally (Oral group) or vaginally (Vaginal group). The primary outcomes measured were changes in the Bishop score following treatment, induction of labor (IOL) success rates, requirement for oxytocin augmentation, duration of labor, mode of delivery, and cesarean section rates.

RESULTS

Significant enhancements in Bishop scores, decreased cesarean section rates and increased success rates of IOL were noted in both administration groups. The incidence of vaginal delivery within 24 h was significantly higher in the Vaginal group compared to the Oral group. Adverse effects, including nausea, uterine overcontraction, hyperfrequency of uterine contraction and uterine hyperstimulation without fetal heart rate deceleration, were significantly more prevalent in the Vaginal group than in the Oral group.

CONCLUSION

Misoprostol administration, both orally and vaginally, proves effective for labor induction in obese pregnant women with hypertension or diabetes. However, the oral route presents a lower risk of adverse maternal and neonatal outcomes, suggesting its preference for safer labor induction in this demographic.

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%.

Characteristics Associated with Trial of Labor among Patients with Twin Pregnancies

OBJECTIVE

This study aimed to identify patient and provider factors associated with undergoing trial of labor (TOL) among eligible patients with twin gestations.

STUDY DESIGN

This retrospective cohort study of patients with twin gestations who received care at a large tertiary care center from 2000 to 2016 included individuals with live pregnancies greater than 23 weeks of gestation and cephalic-presenting twin. Patients with a prior uterine scar or contraindication to vaginal delivery were excluded from analyses. Maternal and clinical characteristics were compared among patients who did and did not undergo TOL. Multivariable logistic regression models included characteristics chosen a priori and those with bivariable associations with p < 0.1. Interactions between parity and other significant variables in the primary models were also investigated.

RESULTS

Among 1,888 eligible patients, 80.7% (N = 1,524) underwent TOL. Those undergoing TOL were more likely to be younger, multiparous, and have a maternal-fetal medicine physician as the delivering provider (p < 0.01). Hypertensive disorders of pregnancy were less prevalent among patients undergoing TOL (20.2 vs. 27.8%, p < 0.01). In multivariable analysis, advanced maternal age (adjusted odds ratio [aOR]: 0.55, 95% confidence interval [CI]: 0.40-0.74) and nulliparity (aOR: 0.36, 95% CI: 0.25-0.52) conferred a lower odds of TOL, while having a maternal-fetal medicine provider (aOR: 2.74, 95% CI: 1.55-4.83) was associated with higher odds. Interaction analyses demonstrated no significant interaction effects between parity and other characteristics. Among those undergoing a TOL, 76.0% (1,158/1,524) had a successful vaginal delivery of both twins, with 48.1% (557/1,158) having breech extraction of the second twin.

CONCLUSION

In this cohort of twin gestations with a high frequency of TOL, patient and provider characteristics are associated with attempting vaginal delivery. Variation in provider practices suggests differing skills and comfort with twin vaginal delivery may influence route of delivery decision-making in patients with twins.

KEYPOINTS

· Most patients with twin pregnancies undergoing TOL had successful vaginal deliveries.. · Having an MFM delivering provider was associated with higher odds of attempting twin TOL.. · Nulliparity and advanced maternal age were associated with lower odds of twin TOL..

An Externally Validated Model to Predict Prolonged Induction of Labor with an Unfavorable Cervix

OBJECTIVE

 To develop and externally validate a prediction model to calculate the likelihood of prolonged induction of labor (induction start to delivery time > 36 hours).

STUDY DESIGN

 This was a retrospective cohort study of all nulliparous women with singleton pregnancies and vertex presentation at term who underwent induction of labor and had a vaginal delivery at a single academic center. Women with contraindications for vaginal delivery were excluded. Analyses were limited to women with unfavorable cervix (both simplified Bishop score [dilation, station, and effacement: range 0-9] <6 and cervical dilation <3 cm). Prolonged induction of labor was defined as the duration of induction (induction start time to delivery) longer than 36 hours. A backward stepwise logistic regression analysis was used to identify the factors associated with prolonged induction of labor by considering maternal characteristics and comorbidities as well as fetal conditions. The final model was validated using an external dataset of the Consortium on Safe Labor after applying the same inclusion and exclusion criteria. We developed a receiver observer characteristic curve with area under the curve (AUC) in validation cohorts.

RESULTS

 Of 2,118 women, 364 (17%) had prolonged induction of labor. Factors associated with prolonged induction of labor included body mass index at admission, hypertension, fetal conditions, and epidural. Factors including younger maternal age, prelabor rupture of membranes, and a more favorable simplified Bishop score were associated with a decreased likelihood of prolonged induction of labor. In the external validation cohort, 4,418 women were analyzed, of whom 188 (4%) had prolonged induction of labor. The AUC of the final model was 0.76 (95% confidence interval: 0.73-0.80) for the external validation cohort. The online calculator was created and is available at: https://medstarapps.org/obstetricriskcalculator.

CONCLUSION

 Our externally validated model was efficient in predicting prolonged induction of labor with an unfavorable cervix.

KEY POINTS

· The number of inductions of labor at 39 weeks' gestation and beyond has been increasing.. · Our model had a good prediction of prolonged induction of labor.. · An online calculator has been created and available..

The Relationship between Gestational Weight Gain and Cesarean Delivery among Patients undergoing Induction of Labor

OBJECTIVE

This study aimed to determine the impact of pregnancy weight gain above National Academy of Medicine (NAM) guidelines on cesarean delivery rates following induction.

STUDY DESIGN

This is a secondary analysis of a prospective cohort study of patients who underwent induction at a single tertiary care center between July 2017 and July 2019. Included in the primary study were patients undergoing term (≥37 weeks) labor induction with a singleton gestation, intact membranes, and unfavorable cervical examination (Bishop score of ≤6 and cervical dilation ≤ 2 cm). Eligibility for this analysis was limited to patients with a documented prenatal body mass index (BMI) < 20 weeks' gestation. The primary exposure was gestational weight gain greater than NAM guidelines (WGGG) for a patient's initial BMI category. The primary outcome was cesarean delivery for any indication.

RESULTS

Of 1,610 patients included in the original cohort, 1,174 (72.9%) met inclusion criteria for this analysis and 517 (44.0%) of these had weight gain above NAM guidelines. Of the entire cohort, 60.0% were Black and 52.7% had private insurance. In total, 160 patients (31%) with WGGG underwent cesarean compared with 127 patients (19.3%) without WGGG (p < 0.001), which equates to a 59% increased odds of cesarean when controlling for initial BMI category, parity, gestational diabetes, and indication for induction (Adjusted Odds Ratio [aOR] 1.58, 95% confidence interval [CI] 1.17-2.12). Among only nulliparous patients, WGGG was associated with an increased odds of cesarean (26.4 vs. 38.2%, aOR 1.50, 95% CI 1.07-2.10). In multiparous patients, however, there was no difference in cesarean between those with and without WGGG (8.8 vs. 14.1%, aOR 1.85, 95% CI 0.96-3.58).

CONCLUSION

This study demonstrates that weight gain above NAM guidelines is associated with more than a 50% increased odds of cesarean. Patients should be informed of this association as gestational weight gain may be a modifiable risk factor for cesarean delivery.

KEY POINTS

· Weight gain above NAM guidelines was associated with a 59% increased odds of cesarean delivery.. · Nulliparous patients with weight gain above NAM guidelines are at higher risk of cesarean delivery.. · No difference in cesarean delivery among multiparous patients regardless of gestational weight gain..

Developing a nomogram for estimating the risk of needing to perform a caesarean section after induction of labour in pregnancies using a COOK® Cervical Ripening Balloon

BACKGROUND

Using a COOK® Cervical Ripening Balloon (CCRB) for cervical maturity has become a common clinical practice for the induction of labour (IOL).

OBJECTIVE

To develop and validate a predictive instrument that could estimate the risk of a caesarean after IOL in term pregnancies with CCRB treatment.

METHODS

The medical records of 415 pregnant women requiring IOL from January 2018 to October 2022 were retrospectively reviewed and randomly selected for training (290) and validation (125) sets in a 7:3 ratio. A model for predicting the risk of a caesarean was virtualised by a nomogram using logistic regression analysis.

RESULTS

After completing the multivariate analysis, parity (odds ratio [OR] = 0.226; p= 0.017), modified Bishop score at induction (OR =0.688; p= 0.005) and the artificial rupture of membranes (OR = 0.436; p= 0.010) were identified as the predictors for implementing a caesarean delivery after IOL. The decision curve analysis showed that the model achieved a net benefit across all threshold probabilities.

CONCLUSION

We successfully constructed a nomogram for caesarean delivery after IOL in pregnancies with CCRB treatment using factors including parity, modified Bishop score at induction and the artificial rupture of membrane.

Establishment and Validation of a Machine Learning-Based Prediction Model for Termination of Pregnancy via Cesarean Section

Objective

This study aimed to investigate the risk factors of cesarean section and establish a prediction model for cesarean section based on the characteristics of pregnant women.

Methods

The clinical characteristics of 2552 singleton pregnant women who delivered a live baby between January 2020 and December 2021 were retrospectively reviewed. They were divided into vaginal delivery group (n = 1850) and cesarean section group (n = 702). These subjects were divided into training set (2020.1-2021.6) and validation set (2021.7-2021.12). In the training set, univariate analysis, Lasso regression, and Boruta were used to screen independent risk factors for cesarean section. Four models, including Logistic Regression (LR), K-Nearest Neighbor (KNN), Classification and Regression Tree (CART), and Random forest (RF), were established in the training set using K-fold cross validation, hyperparameter optimization, and random oversampling techniques. The best model was screened, and Sort graph of feature variables, univariate partial dependency profile, and Break Down profile were delineated. In the validation set, the confusion matrix parameters were calculated, and receiver operating characteristic curve (ROC), precision recall curve (PRC), calibration curve, and clinical decision curve analysis (DCA) were delineated.

Results

The risk factors of cesarean section included age and height of women, weight at delivery, weight gain, para, assisted reproduction, abnormal blood glucose during pregnancy, pregnancy hypertension, scarred uterus, premature rupture of membrane (PROM), placenta previa, fetal malposition, thrombocytopenia, floating fetal head, and labor analgesia. RF had the best performance among the four models, and the accuracy of confusion matrix parameters was 0.8956357. The Matthews correlation coefficient (MCC) was 0.753012. The area under ROC (AUC-ROC) was 0.9790787, and the area under PRC (AUC-PRC) was 0.957888.

Conclusion

RF prediction model for caesarean section has high discrimination performance, accuracy and consistency, and outstanding generalization ability.

Predicting cesarean delivery among gravidas with morbid obesity-a machine learning approach

BACKGROUND

Women with obesity have higher rates of complications following cesarean delivery, such as wound infection and endometritis, with risks being the highest if a cesarean delivery is performed after labor. Previous efforts at predicting whether a patient's labor course would ultimately result in cesarean delivery have been intermediate with area under the curve in the 0.75 to 78 range.

OBJECTIVE

This study aimed to assess whether machine learning algorithms would outperform traditional modeling in developing a cesarean delivery prediction model among gravidas with morbid obesity (body mass index of ≥40 kg/m2) to determine whether a primary cesarean delivery may be beneficial.

STUDY DESIGN

This was a secondary analysis of a retrospective cohort of 1298 patients with morbid obesity presenting for vaginal delivery at ≥37 weeks of gestation between 2011 and 2016 at a single institution. Data available at the time of admission and delivery were modeled using logistic regression, decision tree, random forest, and support vector modeling with evaluation of area under the curve, accuracy, sensitivity, and specificity.

RESULTS

Logistic regression demonstrated an area under the curve of 0.816 (95% confidence interval, 0.810-0.817), which was superior to machine learning models when evaluating data at the time of delivery (demographic data, initial cervical examinations, comorbidities, and obstetrical interventions) (P<.001). However, there was no significant difference between most machine learning models and logistic regression area under the curve of 0.799 (95% confidence interval, 0.795-0.804) when evaluating parameters available at the time of admission (demographic data, initial cervical examinations, and comorbidities). Race was noted to be a significant predictor in both models (P<.001).

CONCLUSION

Machine learning and traditional modeling techniques are likely equivalent concerning cesarean delivery prediction in this population. The models developed showed good discrimination and may be used to guide clinical decision-making concerning the optimal mode of delivery.

Prediction of Emergency Cesarean Section Using Detectable Maternal and Fetal Characteristics Among Saudi Women

Background

The worldwide rate of cesarean section (CS) is increasing. Development of prediction models for a specific population may improve the unmet need for CS as well as reduce the overuse of CS.

Objective

To explore risk factors associated with emergency CS, and to determine the accuracy of predicting it.

Methods

A retrospective analysis of the medical records of women who delivered between January 1, 2021-December 2022 was conducted, relevant maternal and neonatal data were retrieved.

Results

Out of 1793 deliveries, 447 (25.0%) had emergency CS. Compared to control, the risk of emergency CS was higher in primiparous women (OR 2.13, 95% CI 1.48 to 3.06), in women with higher Body mass index (BMI) (OR 1.77, 95% CI 1.27 to 2.47), in association with history of previous CS (OR 4.81, 95% CI 3.24 to 7.15) and in women with abnormal amniotic fluid (OR 2.30, 95% CI 1.55 to 3.41). Additionally, women with hypertensive disorders had a 176% increased risk of emergency CS (OR 2.76, 95% CI 1.35-5.63). Of note, the risk of emergency CS was more than three times higher in women who delivered a small for gestational age infant (OR 3.29, 95% CI 1.93-5.59). Based on the number of risk factors, a prediction model was developed, about 80% of pregnant women in the emergency CS group scored higher grades compared to control group. The area under the curve was 0.72, indicating a good discriminant ability of the model.

Conclusion

This study identified several risk factors associated with emergency CS in pregnant Saudi women. A prediction model showed 72% accuracy in predicting the likelihood of emergency CS. This information can be useful to individualize the risk of emergency CS, and to implement appropriate measures to prevent unnecessary CS.

Effect of maternal age and body mass index on induction of labor with oral misoprostol for premature rupture of membrane at term: A retrospective cross-sectional study

The aim of this study was to evaluate the effect of maternal age and body mass index (BMI) on induction of labor with oral misoprostol for premature rupture of membrane (PROM) at term. We have conducted retrospective cross-sectional study, including only term (37 weeks or more of gestation) PROM in healthy nulliparous women with a negative vaginal-rectal swab for group B streptococcus, a single cephalic fetus with normal birthweight, and uneventful pregnancy that were induced after 24 h from PROM. Ninety-one patients were included. According to the multivariate logistic regression, age and BMI odds ratio (OR) for induction success were 0.795 and 0.857, respectively. The study population was divided into two groups based on age (<35 and ≥35 years) and obesity (BMI <30 and ≥30). Older women reported a higher induction failure rate (p < 0.001); longer time to cervical dilation of 6 cm (p = 0.03) and delivery (p < 0.001). Obese women reported a higher induction failure rate (p = 0.01); number of misoprostol doses (p = 0.03), longer time of induction (p = 0.03) to cervical dilatation of 6 cm (p < 0.001), and delivery (p < 0.001); and higher cesarean section (p = 0.012) and episiotomy rate (p = 0.007). In conclusion, maternal age and BMI are two of the main factors that influence oral misoprostol efficacy and affect the failure of induction rate in term PROM.

Validated Calculators Predicting Cesarean Delivery After Induction: Accuracy in an External Population

OBJECTIVE

To evaluate the performance of two previously published calculators in predicting cesarean delivery after induction of labor in an external population.

METHODS

This was a cohort study including all nulliparous pregnant patients with singleton, term, vertex fetuses; intact membranes; and unfavorable cervices who underwent induction of labor between 2015 and 2017 at an academic tertiary care institution. Individual predicted cesarean risk scores were calculated with two previously published calculators. For each calculator, patients were stratified into three risk groups (lower, middle, and upper thirds) of approximately equivalent size. Predicted and observed incidences of cesarean delivery were compared with two-tailed binomial tests of probability in the overall population and in each risk group.

RESULTS

A total of 846 patients met inclusion criteria, and 262 (31.0%) had cesarean deliveries, which was significantly lower than overall predicted rates of 40.0% and 36.2% with the two calculators (both P<.01). Both calculators significantly overestimated risk of cesarean delivery in higher risk tertiles (all P<.05). The areas under the receiver operating characteristic for both calculators were 0.57 or less in the overall population and in each risk group, suggesting poor predictive value. Higher predicted risk tertile in both calculators was not associated with any maternal or neonatal outcomes except wound infection.

CONCLUSION

Both previously published calculators had poor performance in this population, with neither calculator accurately predicting the incidence of cesarean delivery. Patients and health care professionals might be discouraged regarding trial of labor induction by falsely high predicted risk-of-cesarean scores. We caution against widespread implementation of these calculators without further population-specific refinement and adjustment.

Predictive factors for vaginal delivery by induction of labor in uncomplicated pregnancies at 40-41 gestational weeks: A Japanese prospective single-center cohort study

AIM

We investigated cervical parameters predictive of vaginal delivery in elective labor induction among women at 40-41 gestational weeks.

METHODS

This Japanese prospective single-center cohort study was conducted between July 2019 and June 2020. We enrolled women with an uncomplicated singleton pregnancy who underwent labor induction at 40-41 gestational weeks. We analyzed background characteristics and cervical parameters, including Bishop score, cervical length, posterior cervical angle, and changes in cervical parameters before and after cervical dilatation. The endpoint was the rate of vaginal delivery.

RESULTS

Of 142 eligible participants, all 24 multiparous women underwent vaginal delivery. Among the nulliparous women (n = 118), the following categories showed significantly higher rates of vaginal delivery: Bishop scores of ≥6 before and after dilatation, compared with Bishop score <6 (adjusted prevalence ratio (aPR) [95% confidence interval (CI)]; 1.58 [1.17-2.13] and 1.56 [1.13-2.14], respectively) and cervical length of <10 and 10-20 mm before dilation, compared with cervical length of >30 mm (aPR [95% CI]; 1.47 [1.00-2.15] and 2.13 [1.42-3.18], respectively). The posterior cervical angle and other background characteristics showed no significant associations. Furthermore, women with cervical lengths of ≥20 mm before and <20 mm after dilatation showed a higher rate of vaginal delivery, compared to cervical length of ≥20 mm even after dilatation (aPR [95% CI]; 1.95 [1.19-3.20]).

CONCLUSIONS

High Bishop score, short cervical length, and changes in cervical length with dilatation are potential independent predictors of vaginal delivery following elective labor induction in nulliparous women at 40-41 gestational weeks.

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.

Deriving a prediction model for emergency cesarean delivery following induction of labor in singleton term pregnancies

OBJECTIVES

To derive a prediction model combining various clinical factors associated with increased risk of emergency cesarean section following induction of labor in women with unfavorable cervix.

METHODS

All women with singleton term pregnancies undergoing induction of labor and fulfilling inclusion criteria were included in this cross-sectional study after supplying consent. Women with a Bishop score of 6 or less were induced with dinoprostone gel. Multiple regression analysis was used to find the most significant independent predictive factors and these factors were used to develop the predictive model and calculator.

RESULTS

After multiple logistic regression, risk of emergency cesarean after induction of labor was significantly associated with the following variables: height (adjusted odds ratio [aOR] 0.955, P = 0.033), nulliparity (aOR 3.987, P < 0.001), closed cervix (aOR 2.030, P = 0.030), fetal station -3 above ischial spine (aOR 2.719, P = 0.043), firm or medium cervical consistency (aOR 2.028, P = 0.004), cervical length 3 cm or longer (aOR 3.090, P = 0.015), posterior cervix (aOR 2.112, P = 0.002).

CONCLUSION

Use of a prediction model would help to reduce the number of emergency cesarean sections secondary to unsuccessful inductions and help in the reduction of maternal and perinatal morbidity.

Quality Initiative to Reduce Failed Trial of Labor after Cesarean Using Calculated VBAC Success Likelihood

OBJECTIVE

 Vaginal birth after cesarean can reduce morbidity associated with multiple cesarean deliveries. Failed vaginal birth after cesarean is associated with increased maternal and neonatal morbidity. The Maternal-Fetal Medicine Units Vaginal Birth After Cesarean calculator is a validated tool to predict the likelihood of successful trial of labor after cesarean. Predicted likelihood < 60% has been associated with increased maternal and neonatal morbidity. We sought to determine if formal incorporation of calculated vaginal birth after cesarean likelihood into patient-centered counseling would reduce failed vaginal birth after cesarean.

STUDY DESIGN

 This is a quality improvement intervention at a single tertiary-care academic medical center, in which standardized patient counseling was implemented, facilitated by an electronic medical record template featuring patient-specific likelihood of vaginal birth after cesarean success. Term singleton pregnancies with history of one to two cesareans were included; those with contraindication to labor were excluded. Historical controls (January 2016-December 2018, n = 693) were compared with a postimplementation cohort (January 2019-April 2020, n = 328). Primary outcome was failed vaginal birth after cesarean.

RESULTS

 Fewer patients in the postintervention cohort had a history of an arrest disorder (PRE: 48%, 330/693 vs. POST: 40%, 130/326, p = 0.03); demographics were otherwise similar, including the proportion of patients with <60% likelihood of success (PRE: 39%, 267/693, vs. POST: 38%, 125/326). Following implementation, induction of labor in patients with a <60% likelihood of successful vaginal birth after cesarean decreased from 17% (45/267) to 5% (6/125, p < 0.01). The proportion of failed vaginal birth after cesarean decreased from 33% (107/329) to 22% (32/143, p = 0.04). Overall vaginal birth after cesarean rate did not change (PRE: 32%, 222/693, vs. POST: 34%, 111/326, p = 0.52).

CONCLUSION

 An intervention targeting provider counseling that included a validated vaginal birth after cesarean success likelihood was associated with decreased risk of failed trial of labor after cesarean without affecting overall vaginal birth after cesarean rate.

KEY POINTS

· Labored cesarean increases maternal morbidity.. · Application of the Maternal-Fetal Medicine Units (MFMU) calculator to antenatal counseling decreased labored cesarean.. · Application of the MFMU calculator to antenatal counseling did not decrease overall vaginal birth after cesarean rate..

Prognostic factors for successful induction of labor in intrauterine growth restriction after 36 weeks of gestation

OBJECTIVE

In comparison to eutrophic fetuses, intra uterine growth restriction fetuses (IUGR) have a higher risk of perinatal morbi-mortality. There are no guidelines on the labor induction of labor (IOL) method to be performed in IUGR. The main objective was to determine fetal and maternal predictive factors of successful induction in IUGR fetuses from 36 weeks. Study design We conducted a retrospective cohort single-center study including 320 women with a cephalic fetal presentation. Labour was induced after 36 weeks for suspected IUGR between January 2013 and December 2019.

RESULTS

Among the 320 patients, 246 were delivered vaginally (76.9 %) and 74 had a cesarean (23.1 %). Prognostic factors for successful IUGR induction were nonscarring uterus (OR 8.41; 95 %CI [2.92-24.21]), absence of preeclampsia (OR 7.14; 95 %CI [2.42-21.03]), multiparity (OR 4.32; 95 %CI [1.83-10.18]), normal fetal heart rate before IOL (OR 2.99; 95 %CI [1.24-7.22]) and BMI < 30 (OR 3.54; 95 %CI [1.62-7.72]). Doppler abnormalities, method and number of line of IOL, cervical evaluation were not significant in our study.

CONCLUSION

The prognostic factors for successful IUGR induction are essentially maternal. Thus, a low BMI, multiparity, nonscarring uterus, absence of preeclampsia, and a normal FHR are good prognostic factors in IUGR induction.

Term induction of labour in nulliparous women: When to draw the line?

Objective

Study design

Results

Conclusion

Development and Validation of a Nomogram to Estimate Risk of Cesarean After Induction of Labor in Term Pregnancies with an Unfavorable Cervix in Iran

This study aimed to develop and validate a labor induction nomogram for nulliparous and multiparous women who were 38 weeks pregnant or more and had their labor induced by an unfavorable cervix. This prospective study was conducted on 300 individuals (200 for nomogram development and 100 for nomogram validation). Height, body mass index at delivery, parity, gestational age, adjusted bishop score, and cesarean section risk assessment were all recorded on a checklist. Participants were followed until they gave birth, and the type of delivery was noted in the checklist. Out of 300 labor inductions, 80 (26.7%) underwent a cesarean section. Cesarean risk estimation was the only predictor of delivery type based on multivariate logistic regression. The AUC (Area Under the Curve) in development group was 0.68 and in validation group was 0.71. The developed nomogram for predicting of cesarean section risk following labor induction has a relatively good predictive value among women.

A Model to Predict Vaginal Delivery and Maternal and Neonatal Morbidity in Low-Risk Nulliparous Patients at Term

OBJECTIVE

This study aimed to develop and validate a model to predict the probability of vaginal delivery (VD) in low-risk term nulliparous patients, and to determine whether it can predict the risk of severe maternal and neonatal morbidity.

METHODS

Secondary analysis of an obstetric cohort of patients and their neonates born in 25 hospitals across the United States (n = 115,502). Trained and certified research personnel abstracted the maternal and neonatal records. Nulliparous patients with singleton, nonanomalous vertex fetuses, admitted with an intent for VD ≥ 37 weeks were included in this analysis. Patients in active labor (cervical exam > 5 cm), those with prior cesarean and other comorbidities were excluded. Eligible patients were randomly divided into a training and test sets. Based on the training set, and using factors available at the time of admission for delivery, we developed and validated a logistic regression model to predict the probability of VD, and then estimated the prevalences of severe morbidity according to the predicted probability of VD.

RESULTS

A total of 19,611 patients were included. Based on the training set (n = 9,739), a logistic regression model was developed that included maternal age, body mass index (BMI), cervical dilatation, and gestational age on admission. The model was internally validated on the test set (n = 9,872 patients) and yielded a receiver operating characteristic-area under the curve (ROC-AUC) of 0.71 (95% confidence interval [CI]: 0.70-0.72). Based on a subset of 18,803 patients with calculated predicted probabilities, we demonstrated that the prevalences of severe morbidity decreased as the predicted probability of VD increased (p < 0.01).

CONCLUSION

In a large cohort of low-risk nulliparous patients in early labor or undergoing induction of labor, at term with singleton gestations, we developed and validated a model to calculate the probability of VD, and maternal and neonatal morbidity. If externally validated, this calculator may be clinically useful in helping to direct level of care, staffing, and adjustment for case-mix among various systems.

KEY POINTS

· A model to predict the probability of vaginal delivery in low-risk nulliparous patients at term.. · The model also predicts the risk of severe maternal and neonatal morbidity.. · The prevalences of severe morbidity decrease as the probability of vaginal delivery increases..

Prediction of Emergency Cesarean Section Using Machine Learning Methods: Development and External Validation of a Nationwide Multicenter Dataset in Republic of Korea

This study was a multicenter retrospective cohort study of term nulliparous women who underwent labor, and was conducted to develop an automated machine learning model for prediction of emergent cesarean section (CS) before onset of labor. Nine machine learning methods of logistic regression, random forest, Support Vector Machine (SVM), gradient boosting, extreme gradient boosting (XGBoost), light gradient boosting machine (LGBM), k-nearest neighbors (KNN), Voting, and Stacking were applied and compared for prediction of emergent CS during active labor. External validation was performed using a nationwide multicenter dataset for Korean fetal growth. A total of 6549 term nulliparous women was included in the analysis, and the emergent CS rate was 16.1%. The C-statistics values for KNN, Voting, XGBoost, Stacking, gradient boosting, random forest, LGBM, logistic regression, and SVM were 0.6, 0.69, 0.64, 0.59, 0.66, 0.68, 0.68, 0.7, and 0.69, respectively. The logistic regression model showed the best predictive performance with an accuracy of 0.78. The machine learning model identified nine significant variables of maternal age, height, weight at pre-pregnancy, pregnancy-associated hypertension, gestational age, and fetal sonographic findings. The C-statistic value for the logistic regression machine learning model in the external validation set (1391 term nulliparous women) was 0.69, with an overall accuracy of 0.68, a specificity of 0.83, and a sensitivity of 0.41. Machine learning algorithms with clinical and sonographic parameters at near term could be useful tools to predict individual risk of emergent CS during active labor in nulliparous women.

Failed induction of labor and associated factors in Adama Hospital Medical College, Oromia Regional State, Ethiopia

Background:

Failed induction of labor continues to be a public health challenge throughout the world. This failed induction of labor is associated with a higher rate of maternal and fetal morbidity because it increases the unwanted effect of emergency cesarean section. It is also associated with an increased risk of numerous adverse maternal and perinatal outcomes such as uterine rupture, nonreassuring fetal heart rate tracing, postpartum hemorrhage, stillbirth, and severe birth asphyxia. Thus, this study was aimed to assess the failed induction of labor and associated factors in the Adama Hospital Medical College, Oromia Regional State, Ethiopia.

Methods:

A facility-based cross-sectional study was conducted from 1 to 30 December 2020 in Adama Hospital Medical College, Ethiopia. A total of 379 women who underwent labor induction in the Adama Hospital Medical College from December 2019 to November 2020 were enrolled in the study. The participants’ charts were selected using a simple random sampling technique. Data were collected using a pretested and validated structured questionnaire. Descriptive statistics were carried out using frequency tables, proportions, and summary measures. Predictors were assessed using a multivariable logistic regression analysis model and reported using adjusted odds ratio with 95% confidence interval. Statistical significance was considered at a p value <0.05.

Results:

Of 379 induced labor included in the study, the proportion of failed induction was found to be 29.6% (95% confidence interval (25.2, 34.3)). Prelabor rupture of the membrane was found to be the most common indication for induction of labor (46.4%) followed by a hypertensive disorder of pregnancy (21.6%). In the final model of multivariable analysis, predictors such as: nulliparity (adjusted odds ratio = 2.32, 95% confidence interval (1.08, 5.02)), unfavorable cervical status (adjusted odds ratio = 3.46, 95% confidence interval (1.51, 7.94)), prelabor rupture of membrane (adjusted odds ratio = 2.60, 95% confidence interval (1.14, 5.91)), hypertensive disorder of pregnancy (adjusted odds ratio = 3.01;95% confidence interval (1.61, 558)), preinduction membrane status (adjusted odds ratio = 3.63; 95% confidence interval (1.48, 8.86)), and birth weight of greater than 4000 g (adjusted odds ratio = 4.33; 95% confidence interval (1.44, 13.02)) were statistically associated with failed induction of labor.

Conclusion:

The prevalence of failed induction of labor was relatively high in this study area because more than a quarter of mothers who underwent induction of labor had failed induction. This calls for all stakeholders to adhere to locally available induction protocols and guidelines. In addition, pre-induction conditions must be a top priority to improve the outcome of induction of labor.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Is there an increased risk of cesarean section in obese women after induction of labor? A retrospective cohort study

Background

Obesity is increasing in Sweden and is also of huge global concern. Obesity increases the risk of complications during pregnancy and the need for the induction of labor. Induction of labor increases the number of complications during delivery, leading to women with more negative birth experience. This study investigated how maternal body mass index (BMI) during antenatal care enrollment affects labor outcomes (proportion of cesarean section at induction of labor).

Method

This was a retrospective cohort study of 3772 women with mixed parity and induction of labor at Soderhospital, Stockholm, in 2009–2010 and 2012–2013. The inclusion criteria were simplex, ≥34 gestational weeks, cephalic presentation and no previous cesarean section. The women were grouped according to BMI, and statistical analyzes were performed to compare the proportion of cesarean sections after induction of labor. The primary outcome was the proportion of cesarean section after induction of labor divided by group of maternal BMI. The secondary outcomes were postpartum hemorrhage >1000 ml, time of labor, fetal outcome data, and indication for emergency cesarean section.

Result

The induction of labor in women with a high BMI resulted in a significantly increased risk of cesarean section, with 18.4–24.1% of deliveries, depending on the BMI group. This outcome persisted after adjustment in women with BMI 25–29.9 (aOR 1.4; 95% CI; 1.1–1.7) and BMI 30–34.9 (aOR 1.5; 95% CI; 1.1–2.1). There was also a significantly higher risk for CS among primiparous women (aOR 3.6; 95% CI; 2.9–45) and if the newborn weighted ≥ four kilos (aOR 1.6; 95% CI; 1.3–2.0).

Conclusion

Our findings show that a higher BMI increased the risk of cesarean section after induction of labor in the groups with BMI 25–34.9. Parity seems to be the strongest risk factor for CS regardless other variables.

Nomogram predicting cesarean delivery undergoing induction of labor among high-risk nulliparous women at term: a retrospective study

Background

Our aim was to create and validate a nomogram predicting cesarean delivery after induction of labor among nulliparous women at term.

Methods

Data were obtained from medical records from Nanjing Drum Tower Hospital. Nulliparous women with singleton pregnancies undergoing induction of labor at term were involved. A total of 2950 patients from Jan. 2014 to Dec. 2015 were served as derivation cohort. A nomogram was constructed by multivariate logistic regression using maternal, fetal and pregnancy characteristics. The predictive accuracy and discriminative ability of the nomogram were internal validated by 1000-bootstrap resampling, followed by external validation of a new dataset from Jan. 2016 to Dec. 2016.

Results

Logistic regression revealed nine predictors of cesarean delivery, including maternal height, age, uterine height, abdominal circumference, estimated fetal weight, indications for induction of labor, initial cervical consistency, cervical effacement and station. Nomogram was well calibrated and had an AUC of 0.73 (95% confidence interval [CI], 0.70-0.75) after bootstrap resampling for internal validation. The AUC in external validation reached 0.67, which was significantly higher than that of three models published previously (P<0.05).

Conclusions

This validated nomogram, constructed by variables that were obtained form medical records, can help estimate risk of cesarean delivery before induction of labor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04386-8.

Caesarean section rates in primigravid women categorised by age and BMI

The rising caesarean section (CS) rate is a complex issue, particularly in an increasingly heterogenous nulliparous population. The study aim was to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. This was a retrospective review of CS procedures of nulliparous women in two centres in Ireland (2014 through 2017). Data were obtained for 17,177 women from the hospital databases and CS procedures determined for each age and BMI category. Significant differences were observed when CS rates were stratified in this manner. The CS rates for women <20 years/BMI < 18.5 was 8.8 versus 57.6% for women 35 - 39 years/BMI 30 - 34 and 76 - 100% for all women >45 years (p<.005). The development of customised charts subdivided by age and BMI may be a useful counselling tool and assist in the comparison of rates between units.Impact statementWhat is already known on this subject? It is well known that along with rising CS rates globally, there have also been significant changes in maternal demographics-with increasing maternal age at first birth and increasing maternal BMI. It is well established that both of these factors affect the rate of CS in a population.What do the results of this study add? This study sought to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. The results of the study showed an increasing CS rate for increasing age and BMI categories that was statistically significant.What are the implications of these findings for clinical practice and/or further research? Additional research using larger population data sets could allow the development of customised charts for nulliparous women subdivided by age and BMI which could act as a useful counselling tool in clinical practice, as well as assist in the comparison of CS rates between units.

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.

Risk of caesarean delivery in labour induction: a systematic review and external validation of predictive models

BACKGROUND

Despite the existence of numerous published models predicting the risk of caesarean delivery in women undergoing induction of labour (IOL), validated models are scarce.

OBJECTIVES

To systematically review and externally assess the predictive capacity of caesarean delivery risk models in women undergoing IOL.

SEARCH STRATEGY

Studies published up to 15 January 2021 were identified through PubMed, CINAHL, Scopus and ClinicalTrials.gov, without temporal or language restrictions.

SELECTION CRITERIA

Studies describing the derivation of new models for predicting the risk of caesarean delivery in labour induction.

DATA COLLECTION AND ANALYSIS

Three authors independently screened the articles and assessed the risk of bias (ROB) according to the prediction model risk of bias assessment tool (PROBAST). External validation was performed in a prospective cohort of 468 pregnancies undergoing IOL from February 2019 to August 2020. The predictive capacity of the models was assessed by creating areas under the receiver operating characteristic curve (AUCs), calibration plots and decision curve analysis (DCA).

MAIN RESULTS

Fifteen studies met the eligibility criteria; 12 predictive models were validated. The quality of most of the included studies was not adequate. The AUC of the models varied from 0.520 to 0.773. The three models with the best discriminative capacity were those of Levine et al. (AUC 0.773, 95% CI 0.720-0.827), Hernández et al. (AUC 0.762, 95% CI 0.715-0.809) and Rossi et al. (AUC 0.752, 95% CI 0.707-0.797).

CONCLUSIONS

Predictive capacity and methodological quality were limited; therefore, we cannot currently recommend the use of any of the models for decision making in clinical practice.

TWEETABLE ABSTRACT

Predictive models that predict the risk of cesarean section in labor inductions are currently not applicable.

Incidence of and Risk Factors for Failed Induction of Labor Using a Contemporary Definition

OBJECTIVE

To estimate the incidence of failed induction of labor and the associated patient risk factors.

METHODS

We performed a case-control study from a cohort of nulliparous women who delivered between 39 and 41 weeks of gestation after an induction of labor in one of seven hospitals. Cases of failed induction were defined using the Obstetric Care Consensus criteria (ie, cesarean delivery performed in early labor [less than 6 cm dilatation] after at least 12 hours of oxytocin administration from membrane rupture). For each case of failed induction, the next four women who did not meet the criteria for failed induction of labor were selected for the control group, matched by hospital. We identified characteristics associated with failed induction of labor using a multivariable conditional logistic regression that was constructed with backward stepwise method for variable selection.

RESULTS

Across the hospitals, 4,123 of 10,175 nulliparous women were induced (40.5%), of whom 82 had a failed induction of labor (2.0%). A total of 328 women were selected for the matched control group. Baseline characteristics were similar between the groups. Compared with women in the control group, women with a failed induction were more likely to have a delivery body mass index (BMI) of 40 or higher (28.0 vs 8.2%, P<.001), shorter height (mean 63.9 vs 64.8 inches, P=.01), and closed cervix on admission (41.5 vs 24.1%, P=.002). Factors significantly associated with induction failure in the multivariable model included: 1) delivery BMI (adjusted odds ratio [aOR] 7.93, 95% CI 3.48-18.09, for BMI 40 or higher relative to BMI lower than 30, 2) height in inches (aOR 0.89, 95% CI 0.80-0.98), and 3) number of centimeters dilated on admission 2 or more (aOR 0.30, 95% CI 0.14-0.65).

CONCLUSION

Failed induction of labor occurs infrequently. Risk factors include shorter height, BMI 40 or higher, and cervical dilatation of less than 2 cm on admission. Even so, most women with these risk factors will not experience failed labor induction.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Application of a Nomogram for Predicting the Risk of Subchorionic Hematoma in Early Pregnancy With In Vitro Fertilization-Embryo Transfer/Frozen Embryo Transfer

BACKGROUND

Subchorionic hematoma (SCH) is common in early pregnancy achieved by in vitro fertilization-embryo transfer/frozen embryo transfer (IVF-ET/FET), and is associated with adverse obstetric outcomes. However, there are no methods known to accurately predict the occurrence of SCH.

OBJECTIVE

To establish a nomogram prediction model for predicting the risk of SCH in early pregnancy with IVF-ET/FET and to analyze pregnancy outcomes of patients with SCH.

METHODS

Patients who underwent IVF-ET/FET treatment and were diagnosed with clinical pregnancy were enrolled in our study. A total of 256 patients with SCH were enrolled in the SCH group, and 526 patients without SCH in the control group. Logistic regression was used to screen risk factors for SCH, and the nomogram was developed according to the regression coefficient of relevant variables. Discrimination, effect, calibration, and the predictive model's clinical usefulness were assessed using the C-index, the area under the receiver operating characteristic standard curve, calibration plot, and decision curve analysis. Internal validation was assessed using bootstrapping validation. The effects of SCH on pregnancy outcomes were analyzed.

RESULTS

A multivariate logistic regression analysis showed that fresh embryo transfer, polycystic ovary syndrome, hydrosalpinx, and thin endometrium were risk factors affecting the occurrence of SCH. Based on the above factors, a predictive model for the risk of SCH was created. The model displayed good discrimination, with a C-index of 0.783 (95% confidence interval: 0.750-0.816), area under the receiver operating characteristic standard curve of 0.783, and good calibration. A high C-index value of 0.765 could still be reached in the interval validation. Decision curve analysis showed that the nomogram was clinically useful when the intervention was decided at the SCH possibility threshold of 4%-87%. For patients with successful deliveries, the occurrence of SCH did not influence the gestational weeks of delivery, mode of delivery, preterm birth, height, and weight of the newborn.

CONCLUSION

We screened the risk factors for SCH in patients who underwent IVF-ET/FET treatment. Successful establishment of a nomogram can effectively predict the occurrence of SCH. Furthermore, the incidence of miscarriage is higher in patients with SCH.

Customized Probability of Vaginal Delivery With Induction of Labor and Expectant Management in Nulliparous Women at 39 Weeks of Gestation

OBJECTIVE

To develop models to predict vaginal delivery in low-risk, nulliparous women contemplating elective induction of labor or expectant management at 39 weeks of gestation.

METHODS

We conducted a secondary analysis of a randomized controlled trial of planned elective induction of labor at 39 weeks of gestation compared with expectant management for low-risk nulliparous women. Two groups were included for this analysis: 1) women who were randomized to the induction of labor group and underwent elective induction at 39 0/7-39 4/7 weeks of gestation and 2) women who were randomized to the expectant management group who experienced spontaneous labor or medically indicated delivery (including postterm). Multivariable logistic regression models were developed for each group using patient characteristics that would be available at the time of counseling. Model selection was based on k-fold cross-validation using backward elimination and variables that remained significant at P<.05 were retained. To compare estimated with observed rates, the elective induction of labor model was then applied to each woman in both groups to estimate individualized predicted probabilities of vaginal delivery with elective induction of labor.

RESULTS

Of 6,106 women enrolled in the trial, 4,661 met criteria for this analysis. Vaginal delivery occurred in 80.6% of the 2,153 women in the elective induction of labor group and 77.2% of the 2,508 women in the expectant management group (P=.005). The final elective induction of labor model included age, height, weight, and modified Bishop score (area under the receiver operating characteristic curve [AUROC] 0.72, 95% CI 0.70-0.75). The same variables were included in the final expectant management model (AUROC 0.70, 95% CI 0.67-0.72). Across the range of predicted probability deciles derived from the elective induction of labor model, almost all women who underwent elective induction of labor at 39 weeks of gestation had a higher observed chance of vaginal delivery than expectant management.

CONCLUSION

Irrespective of the individual predicted chance of vaginal delivery from elective induction of labor at 39 weeks of gestation, vaginal delivery is generally more frequent if elective induction of labor is undertaken rather than expectant management. These data can be used to counsel nulliparous women regarding their "customized" chances of vaginal delivery as they choose between elective induction of labor or expectant management at 39 weeks of gestation.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT01990612.

Induction of labour with unfavourable local conditions for suspected fetal growth restriction after 36 weeks of gestation: Factors associated with the risk of caesarean

INTRODUCTION

Induction of labour in women with an unfavourable cervix is associated with a risk of caesarean delivery. When a diagnosis of fetal growth restriction (FGR) is also involved, the risk of intrapartum fetal acidosis increases. The main objective was to identify prognostic factors for the risk of caesarean delivery after induction for suspected FGR after 36 weeks of gestation with an unripe cervix.

MATERIAL AND METHODS

This was a retrospective, single-centre (Port Royal, Paris, France) study of women with a singleton fetus in cephalic presentation, with labour induced at or after 36 weeks for suspected FGR diagnosed during second or third trimester of pregnancy with an unripe cervix (Bishop score under 6) who gave birth between 1 January 2015 and 31 December 2019. A multivariable analysis was performed to identify the factors related to an increased risk of caesarean section.

RESULTS

Of the 146 women included, 56 (38.4 %) had caesarean deliveries. After adjustment, the factors significantly associated with the risk of caesarean were maternal age greater than 39 years (ORa = 4.33 [1.22-17.2], reference: 25-39 years), nulliparity (ORa = 3.49 [1.25-11.2]), and an abnormal fetal umbilical artery Doppler velocimetry (ORa = 3.50 [1.47-8.70]). The risk of poor neonatal condition did not differ significantly between women with vaginal and caesarean deliveries (2.3 % vs 7.3 %, P = 0.21).

CONCLUSION

When FGR is suspected at 36 weeks of gestation and later, induction of labour is a reasonable option, even if the cervix is unripe, as the risk of caesarean delivery appears acceptable and neonatal status is good and similar with both modes of delivery.

Explanatory variables and nomogram of a clinical prediction model to estimate the risk of caesarean section after term induction

The aims of this study were to identify the explanatory variables associated with failure of induction of labour (IOL) and to designate nomograms that predict probability. This retrospective study included 1328 singleton term pregnant women (37-42 weeks). The penalised maximum likelihood estimation (PMLE) method was used instead of traditional logistic regression. Of the 25,678 deliveries that occurred during the study period, 1328 (5.1%) women underwent term delivery. Of those, 1125 (84.7%) had successful vaginal deliveries and 203 (15.3%) had failed vaginal deliveries following use of a dinoprostone slow-release vaginal insert. Explanatory variables were discovered that were associated with delivery failure in term pregnancy undergoing induction of labour with an unfavourable cervix, and a nomogram that predicted probability was developed.IMPACT STATEMENTWhat is already known on this subject? The caesarean rate has continued to climb worldwide over the past decade. Most caesarean sections are performed because of suspected foetal distress or failure to progress. In absolute numbers, most caesarean deliveries are performed in women with a term pregnancy with a foetus in cephalic presentation. Despite these numbers, predicting the mode of delivery by which these women will deliver remains a challenge.What do the results of this study add? Five explanatory variables were strongly associated with failure of dinoprostone delivery of term pregnancies: nulliparity, induction time, premature rupture of membranes, Bishop score and foetal genderWhat are the implications of these findings for clinical practice and further research? The developed nomograms enable fast and easy implementation in clinical practice. After external validation and proof of generalisability, the present model could be used in obstetric clinical management.

Association between Maternal Serum Hormones along the Maternal-Fetal Hypothalamic-Pituitary-Adrenal Axis and Successful Vaginal Delivery Measured Prior to Labor Induction

OBJECTIVE

This study aimed to evaluate if maternal serum hormones along the maternal-fetal hypothalamic-pituitary-adrenal (HPA) axis, when drawn prior to labor induction, differed between women who delivered vaginally and those who underwent cesarean.

STUDY DESIGN

This was a prospective observational study at a single perinatal center performed from August 2017 to May 2018. Nulliparous women with uncomplicated singleton pregnancies ≥39 weeks had maternal serum collected prior to induction. Corticotrophin-releasing hormone (CRH) was measured by ELISA; dehydroepiandrosterone sulfate (DHEA-S), cortisol, estriol (E₃) estradiol (E₂), and progesterone (P₄) were measured by chemiluminescent reaction. Mean analyte concentrations as well as three ratios (E₂/P₄, E₃/P_4, and E₂/E₃) were compared between women who had a vaginal versus cesarean delivery. Logistic regression was used to model the relationship between CRH and the odds of vaginal birth. We estimated that a sample size of 66 would have 90% power to detect a 25% difference in mean CRH levels assuming a vaginal:cesarean ratio of 2:1 with a baseline CRH concentration of 140 (standard deviation = 36) pg/mL.

RESULTS

Of the 88 women who had their serum analyzed, 27 (31%) underwent cesarean. Mean maternal serum CRH levels were similar between the vaginal delivery and cesarean groups (122.6 ± 95.2 vs. 112.3 ± 142.4, p = 0.73). Similarly, there were no significant differences in any other maternal serum analytes or ratios. Logistic regression showed a nonsignificant odds ratio for successful vaginal birth (p = 0.69) even when evaluating only the 16 women who had a cesarean for an arrest disorder (p = 0.08).

CONCLUSION

In low-risk nulliparous women undergoing full-term labor induction, there were no differences noted in a broad array of other maternal-fetal HPA-axis hormones between women who had a vaginal or cesarean delivery.

Externally Validated Prediction Model of Vaginal Delivery After Preterm Induction With Unfavorable Cervix

OBJECTIVE

To create and externally validate a predictive model to calculate the likelihood of vaginal delivery after preterm induction with unfavorable cervix.

METHODS

This was a retrospective cohort study of women with a singleton gestation from a single academic institution who underwent an induction of labor at less than 37 weeks of gestation from January 2009 to June 2018. Women with contraindications for vaginal delivery were excluded. Analyses were limited to women with unfavorable cervix (both simplified Bishop score [dilation, station, and effacement: range 0-9] less than 6 and cervical dilation less than 3 cm). A stepwise logistic regression analysis was used to identify the factors associated with vaginal delivery by considering maternal characteristics and comorbidities as well as fetal conditions. The final model was validated using an external data set of the Consortium on Safe Labor after applying the same inclusion and exclusion criteria. We compared the area under the curve (AUC) of our predictive model and the simplified Bishop score.

RESULTS

Of the 835 women, 563 (67%) had vaginal delivery. Factors associated with vaginal delivery included later gestational age at delivery, higher parity, more favorable simplified Bishop score, and preterm prelabor rupture of membranes. Factors including older maternal age, non-Hispanic Black race, higher body mass index, and abruption were associated with decreased likelihood of vaginal delivery. In the external validation cohort, 1,899 women were analyzed, of whom 1,417 (75%) had vaginal delivery. The AUCs of simplified Bishop score and the final model were 0.65 (95% CI 0.59-0.66) and 0.73 (95% CI 0.72-0.79), respectively, for the external validation cohort. The online calculator was created and is available at www.medstarapps.org/obstetricriskcalculator/ and in the Obstetric Risk Calculator mobile application in the Apple App Store and Google Play Store.

CONCLUSION

Our externally validated model was efficient in predicting vaginal delivery after preterm induction with unfavorable cervix.

The Role of Oxytocin in Primary Cesarean Birth Among Low-Risk Women

INTRODUCTION

To examine whether there is a threshold of oxytocin exposure at which the risk for primary cesarean increases among women who are nulliparous with a term, singleton, vertex fetus (NTSV) and how oxytocin interacts with other risk factors to contribute to this outcome.

METHODS

This was a secondary analysis of the Consortium on Safe Labor data set that used a retrospective cohort study design. Women who met the criteria for NTSV who were not admitted for a prelabor cesarean and for whom oxytocin data were available, were included in the sample. Robust logistic regression was used to examine the association of oxytocin exposure with primary cesarean birth, while controlling for demographic and clinical risk factors and clustering by provider.

RESULTS

The sample comprised 17,331 women who were exposed to oxytocin during labor. The women were predominantly white non-Hispanic (59.2%) with an average (SD) gestational age of 39.4 (1.1) weeks and an 18.5% primary cesarean rate. Exposure to greater than 11,400-milliunits (mU) of oxytocin resulted in 1.6 times increased odds of primary cesarean birth compared with less than 11,400 mU (95% CI 1.01-2.6).

DISCUSSION

Exposure to greater than 11,400 mU of oxytocin in labor was associated with an increased odds of primary cesarean birth in NTSV women.

Risk Factors Associated With Cesarean Delivery After Induction of Labor in Women With Class III Obesity

OBJECTIVE

To assess the risk factors associated with cesarean delivery in women with class III obesity (body mass index [BMI, calculated as weight in kilograms divided by height in meters squared] 40 or higher) who are undergoing induction of labor.

METHODS

This was a retrospective cohort of obese women with a BMI of 40 or higher and singleton pregnancy of 34 weeks of gestation or longer who underwent induction of labor at two large teaching institutions from January 2013 to December 2015. The primary outcome was cesarean delivery. Secondary outcomes included maternal and neonatal composite morbidity. We then assessed the applicability of using a previously developed calculator to predict the risk of cesarean delivery. The area under the receiver operating characteristic (ROC) curve was used as a measure of the ability of the calculator to discriminate between women who underwent cesarean compared with vaginal delivery.

RESULTS

There were 485 women with class III obesity who underwent induction during the study period. Of the 428 women who met inclusion criteria, 81.8% had a BMI of 40-50, 14.5% had a BMI of 50-60, and 3.7% had a BMI higher than 60. The overall cesarean delivery rate was 49.1% (46% with BMI 40-50, 63% with BMI 50-60, and 69% with BMI higher than 60, P=.012). Of the 428 women studied, 77.6% were black and 55% were nulliparous. Nulliparity, height, initial cervical dilation, and modified Bishop score were associated with a higher rate of cesarean delivery in multivariable models. Maternal and neonatal composite morbidity was higher in obese women who underwent cesarean delivery, compared with those who delivered vaginally. The performance of a previously developed induction calculator applied to this cohort had an area under the ROC curve of 75% (95% CI 0.70-0.79).

CONCLUSIONS

In women with class III obesity who underwent labor induction, the cesarean delivery rate approaches 50%. Nulliparity, height, and unfavorable cervical examination were the most significant risk factors for cesarean delivery. This information can be used to augment counseling for the obese patient who is undergoing induction.

PROGNOSTICATION LABOR DYSTOCIA AND CESAREAN SECTION

The article presents the results of the analysis of clinical and anamnestic indicators to create a model for predicting the development of labor dystocia that caused Caesarean section. The most significant prognostic factors included in the prognostic model were fetus-pelvic imbalances, diabetes mellitus, a burdened gynecological history and cardiovascular diseases in the nulliparous women of late reproductive age. Assessment of the totality of risk factors made it possible to achieve an accurate prognosis in 88.6% of cases with a sensitivity of 40.4%, specificity - 92.1%.

Relations between second-trimester aneuploidy screening results and prediction of labour induction success in term pregnancies

We aimed to assess whether the second-trimester maternal serum markers could be used for the prediction of labour induction success. This prospective study enrolled women planned labour induction at term. Women were assigned to one of two groups: vaginal prostaglandin or balloon dilatation. All patients were evaluated for Bishop score, maternal serum oestriol, human chorionic gonadotropin and progesterone at the time of second-aneuploidy screening. The total successful rate for induction of labour was 63.9% in both groups. Maternal serum oestriol multiple of median (MoM) values were significantly lower among the caesarean section group compared to the vaginal delivery group (p < .001). A MoM value of 0.74 for oestriol was associated with a sensitivity of 75.9%, specificity of 41.0%, a positive predictive value of 76.6% and a negative predictive value of 58.0% for a successful induction of labour. Oestriol had a good performance in the prediction of successful induction of labour at term.IMPACT STATEMENTWhat is already known on this subject? Induction of labour is a common procedure undertaken whenever the benefits of prompt delivery outweigh the risks of expectant management. Previous studies have reported that a decreased progesterone/oestradiol ratio and increased maternal plasma oestriol levels are associated with successful labour. What the results of this study add? The results of this study showed that second-trimester oestriol multiple of median (MoM) value provide a significant contribution to the efforts of the prediction of successful induction of labour in term pregnancy, having a sensitivity of 69.8%, specificity of 92.4%, positive predictive value of 83.3% and negative predictive value of 82.5%.What the implications are of these findings for clinical practice and/or further research? This finding can be used as an additional method for prediction of labour induction as well as multiparity and Bishop score. This adds new valuable data to the literature which could be used for systematic reviews and for implementing guidelines and protocols on labour induction.

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.

Externally Validated Score to Predict Cesarean Delivery After Labor Induction With Cervi Ripening

OBJECTIVE

To build a score to predict the risk of cesarean delivery after labor induction with cervical ripening, and to compare its predictive capacities with other already existing scores.

METHODS

This study is a secondary analysis of data collected in the prospective multicenter observational French population-based cohort study Methods of Induction of Labor and Perinatal Outcomes, the primary objective of which was to obtain national data regarding labor induction practices in 94 maternity units. A total of 1,692 patients were randomly split into a derivation data set of 1,024 patients (60%) and an internal validation set of 668 patients (40%). Statistical analyses were performed using a Bayesian approach, allowing the use of priors (ie, previous results published in the literature). The final score is a simplified 50-point score. The score was validated using the internal validation set and an external data set of 4,242 patients from the National Institutes of Health's Consortium for Safe Labor database. We compared the area under the curve (AUC) of our score with two other scores: the modified Bishop score and the Levine score, which is a recently published risk calculator for cesarean delivery after labor induction with unfavorable cervix.

RESULTS

In the multivariate analysis, height, body mass index, gestational age, parity, dilation, effacement, fetal head station, medical indication, suspicion of macrosomia, premature rupture of membranes and concerning fetal status were found to be strongly associated with cesarean delivery. The AUC in the derivation set and internal validation set were 0.76 (0.73-0.79) and 0.74 (0.70-0.78), respectively. On the external validation set, the AUC for the present score, the Levine score, and the modified Bishop score were 0.81 (0.79-0.82), 0.76 (0.75-0.78), and 0.74 (0.73-0.76), respectively.

CONCLUSION

Our easy-to-use, externally validated score is efficient in predicting cesarean delivery after labor induction with cervical ripening.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02477085.

Predictors of emergency cesarean section in women with preexisting diabetes

OBJECTIVE

Preexisting diabetes in pregnancy is associated with a high risk of emergency cesarean section (CS), which is associated with increased risk of maternal and neonatal complications. Thus, the aim of this study was to identify possible predictors of emergency CS in women with preexisting diabetes.

STUDY DESIGN

This is a secondary analysis of a prospective observational study of 204 women with preexisting diabetes (118 with type 1 diabetes and 86 with type 2) with singleton pregnancies recruited at Rigshospitalet, Copenhagen, Denmark from August 2015 to February 2018. Mode of delivery (trial of labor or planned CS) was individually planned in late pregnancy based on clinical variables reflecting maternal and fetal health including glycemic control and ultrasonically estimated fetal weight. Univariate and multivariable analyses were performed to identify possible predictors of in labor emergency CS.

RESULTS

Trial of labor was planned in 79 % (n = 162) of the women of whom 65 % (n = 105) were delivered vaginally and 35 % (n = 57) by an emergency CS, while the remaining 21 % (n = 42) were offered a planned CS. Nulliparity (adjusted odds ratio (aOR) 5.6 95 % CI 1.7-18.8), presence of a hypertensive disorder (aOR 2.8, 95 % CI 1.2-6.7) and previous CS (aOR 6.7, 95 % CI 1.5-28.9) were independently associated with an emergency CS. Maternal height was inversely associated with emergency CS (aOR 0.6 95 %, CI 0.5-0.9 per 5 cm decrease). Neither maternal HbA1c nor ultrasonically estimated fetal size in late pregnancy were associated with emergency CS. Women scheduled for a planned CS were characterized by poorer glycemic control and higher estimated fetal size than those offered a trial of labor.

CONCLUSION

Nulliparity, presence of a hypertensive disorder, previous CS and shorter maternal height were predictors of emergency CS in women with a planned trial of labor, whereas this not was the case for late pregnancy maternal Hba1c or fetal size estimated by ultrasound.

A decade's experience in primipara, term, singleton, vertex parturients with a sustained low rate of CD

Background Cesarean delivery (CD) in primiparas with a term singleton vertex fetus (PTSV) is a sentinel event for the future mode of delivery and determinant of repeat CD risk. We aimed to evaluate the risk factors for primary CD in a population with a decade of sustained low rate of intrapartum CD. Methods This was a retrospective single-center cohort study between 2005 and 2014. The primary outcome of the study was the mode of delivery. PTSV who attempted vaginal delivery were identified and categorized according to the mode of delivery: vaginal delivery vs. CD. Risk factors for intrapartum CD adjusted odds ratio (aOR) [95% confidence interval (CI)] in multivariate analysis were reported. Results During the study, 121,483 deliveries were registered; 26,301 (21.6%) PTSV were admitted in labor, of which 1944 (7.4%) had an intrapartum CD. Significantly in multivariate analysis, this group had a unique risk profile as compared to those who delivered vaginally; non modifiable risks included advanced maternal age: 3.06 (2.16-4.33), P < 0.001; prior multiple (≥3) miscarriages: 1.94 (1.04-3.62), P = 0.04; low (<6) modified admission cervical score: 2.41 (2.07-2.82), P < 0.001; low birth weight (BW): 1.42 (1.00-2.01), P = 0.05 or macrosomia: 2.38 (1.77-3.21), P < 0.001; modifiable risks included induction of labor: 1.79 (1.51-2.13), P < 0.001 and oxytocin labor augmentation: 8.36 (6.84-10.22), P < 0.001. Conclusion In a population of PTSV with a sustained low risk for intrapartum cesarean maintained by a strict labor management, induction of labor remains a significant and sole potentially modifiable risk factor for CD.

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.

Development and Validation of a Risk Prediction Model for Cesarean Delivery After Labor Induction

Objective: The goal of the study was to develop and validate a prediction model for cesarean delivery after labor induction that included factors known before the start of induction, unlike prior studies that focused on characteristics at the time of induction. Materials and Methods: Using 17,370 term labor inductions without documented medical indications occurring at 14 U.S. hospitals, 2007-2012, we created and evaluated a model predicting cesarean delivery. We assessed model calibration and discrimination, and we used bootstrapping for internal validation. We externally validated the model by using 2122 labor inductions from a hospital not included in the development cohort. Results: The model contained eight variables-gestational age, maternal race, parity, maternal age, obesity, fibroids, excessive fetal growth, and history of herpes-and was well calibrated with good risk stratification at the extremes of predicted probability. The model had an area under the curve (AUC) for the receiver operating characteristic curve of 0.82 (95% confidence interval 0.81-0.83), and it performed well on internal validation. The AUC in the external validation cohort was 0.82. Conclusion: This prediction model can help providers estimate a woman's risk of cesarean delivery when planning a labor induction.

The relationship between maternal mental health during pregnancy and type of delivery in the suburbs of Bandar Abbas during 2017-2018

Background: The effect of maternal mental health during pregnancy on Cesarean section through implications of pre- and postnatal birth have narrowly been investigated. The aim of the present study was to investigate the effect of maternal mental health during pregnancy on the type of delivery in the suburbs of Bandar Abbas. Methods: This study used data of 200 mothers registered in a prospective cohort study on pregnant women in the suburbs of Bandar Abbas, South of Iran, during 2016-18. The presence of depression, anxiety, or stress in expecting mothers were measured by DASS-21 questionnaire and the outcome defined as having Cesarean section (Cesarean section) was measured at postpartum. The relative risk (95% CI) was calculated using Cox regression models. All analyses were performed using STATA statistical package, with a significance level of 5%. Results: Information of 196 mothers were collected (98% response rate); the mean age of the participants was 27.28 (±5.62) years. The prevalence of depression, anxiety, and stress was 13.8% (27), 40.4% (40), and 7.6% (15), respectively. Nearly 40% of mothers went through Cesarean section. Compared to mothers with good mental health, the risk of Cesarean section was 96% higher in depressed mothers (RR=2, 95% CI: 1.43-2.74) (p=0.001), 81% higher in anxious mothers (RR=1.81, 95% CI: 1.29-2.53) (p=0.003), and 75% higher in stressed mothers (RR=1.75, 95% CI: 0.86-3.56) (p=0.121). Conclusion: The findings of this study showed that poor mental health, especially anxiety and depression, during pregnancy could increase the risk of Cesarean section. Accordingly, screening protocols for mental health status and prenatal counseling sessions are suggested for pregnant mothers to increase their informed decision on types of delivery.

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.