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

Maternal and perinatal outcomes in nulliparous women with a booking body mass index exceeding 50 kg/m2

BACKGROUND

Women with a body mass index (BMI) >35 kg/m2 carry an increased obstetric risk; however, the experience of the Class IV and above obese nulliparous women is less understood.

AIMS

To describe maternal and perinatal outcomes in nulliparous women of booking BMI > 50 kg/m2.

MATERIALS AND METHODS

A cohort study of 48 nulliparous women who delivered between 2015 and 2019 in a tertiary hospital and had a booking BMI > 50 kg/m2. Obstetric outcome data was collated via electronic and written patient records. The relationship between mode of delivery and BMI was assessed using direct logistic regression. Multiple pregnancies and severe congenital malformations (n = 3) were excluded.

RESULTS

The mean booking BMI was 53.7 kg/m2 (SD 4.05) and mean maternal age was 30.4 years (SD = 5.7). Comorbidities included asthma (43%), essential hypertension (20%) and diabetes (61%). Antenatally, accuracy was compromised in 80% of morphology scans (n = 35). In the perinatal period, 33 women (68.8%) were induced compared to a spontaneous onset of labour in two (4.1%) women. There were nine elective caesarean sections (CS), five of which were for breech presentation. Of those who intended on vaginal delivery (n = 35), 51% (n = 18) had an emergency CS. In these women, the risk of CS increased by a factor of 1.36 for every one point increase in BMI > 50 kg/m2. The average gestational age was 37.5 weeks (SD 2.4) with 14% (n = 6) experiencing preterm deliveries. The incidence of babies born >90th percentile for gestational age was 15 (34%).

CONCLUSION

Increased BMI impairs maternal and perinatal outcomes and significantly increases the risk of emergency CS. BMI > 50 kg/m2 is associated with higher-level interventions and obstetric complications.

The Correct Indication to Induce Labour in a Swiss Cantonal Hospital

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A comparison of 30-, 50-, and 60-mL foley catheter balloon volume and time to achieve cervical ripening for labor induction: A triple-blind randomized controlled trial

Background

Cervical ripening is one of the most important determinants of the outcome of induction of labor. The findings of studies on the most efficacious inflatable catheter balloon volume for pre-induction cervical ripening have been inconclusive.

Aim

To compare the efficacy of the use of different intracervical Foley catheter balloon volumes (30-, 50-, and 60-mL) on cervical ripening.

Subjects and Methods

This study was a triple-blind randomized controlled trial. Two hundred and sixteen women with a Bishop score ≤5 at term were randomly assigned into three groups (1:1:1) to receive an intracervical single size eighteen Foley balloon catheter inflated either with 30-mL (control arm) or 50-mL and 60-mL (intervention arm) of sterile saline which was retained for a duration of 12 h. The primary outcome measures were the mean change in Bishop score and achieving a Bishop score of ≥6 at the twelfth-hour post-Foley catheter balloon insertion.

Results

In the total study population and among nulliparous women, the 50-mL and 60-mL balloons compared with the 30-mL Foley catheter balloon achieved a statistically significantly greater mean change in Bishop scores at the twelfth hour\post-insertion (P = 0.005 and P = 0.001), while the 60-mL balloon compared with the 30-mL and 50-mL balloons achieved statistically significant higher mean change in Bishop scores among multiparous women (P = 0.047 and P = 0.003) and cervical dilatation irrespective of parity (P = 0.003 and P = 0.002), at the twelfth-hour post-insertion. The larger catheter balloons were also associated with a statistically significant greater chance of having an induction to delivery interval of <12 h in nulliparous women P = 0.003.

Conclusion

The findings of this study showed that the larger single Foley catheter balloon volumes (50-mL and 60-mL) aside from being well tolerated and acceptable have the ability to induce faster changes in Bishop score, produce higher cervical dilation, and thus likely reduce significantly the total labor induction process compared to the 30-mL single catheter balloon volume irrespective of parity.

Failed induction of labor in term nulliparous women with an unfavorable cervix: Comparison of cervical ripening by two forms of vaginal prostaglandins (slow-release pessary and vaginal gel)

OBJECTIVE

To compare the rate of failed induction after cervical ripening by two forms of vaginal prostaglandins.

MATERIAL AND METHODS

This two-year retrospective study (January 1, 2016, through December 31, 2017) in two tertiary maternity units included nulliparous women with a singleton fetus in cephalic presentation and an unfavorable cervix requiring labor induction for prolonged pregnancy. The principal endpoint was the rate of failed induction, defined by the performance of a cesarean delivery before 6 cm of dilation. Cervical ripening was initiated by prostaglandins for 24 h, using a slow-release pessary (unit A) or a vaginal gel (unit B). The care protocol of the two groups after the first 24 h were similar. The women's individual characteristics were compared between the two units. The rates of failed induction were then compared between the two units, first by univariate and then by multivariable analysis adjusted for the characteristics that differed significantly between the units.

RESULTS

Among the 17,217 women delivered in the two maternity units during the study period, 178 met our inclusion criteria (125 in unit A (slow-release pessary) and 53 in unit B (vaginal gel)). The rate of failed induction was similar: 21.6% in unit A (slow-release pessary) and 17.0% in unit B (vaginal gel) (P = 0.48). The multivariate analysis did not show any difference about failed induction, time from the onset of induction to delivery, and vaginal delivery rate within 24h.

CONCLUSION

The rate of failed induction of labor did not differ between slow-release pessary and vaginal gel.

Ultrasound in labor: clinical practice guideline and recommendation by the WAPM-World Association of Perinatal Medicine and the PMF-Perinatal Medicine Foundation

This recommendation document follows the mission of the World Association of Perinatal Medicine in collaboration with the Perinatal Medicine Foundation. We aim to bring together groups and individuals throughout the world for standardization to implement the ultrasound evaluation in labor ward and improve the clinical management of labor. Ultrasound in labor can be performed using a transabdominal or a transperineal approach depending upon which parameters are being assessed. During transabdominal imaging, fetal anatomy, presentation, liquor volume, and placental localization can be determined. The transperineal images depict images of the fetal head in which calculations to determine a proposed fetal head station can be made.

Failed induction of labor and associated factors among women delivered in Jigjiga University Sheik Hassan Yabare Referral Hospital: a cross-sectional study

OBJECTIVE

This study was aimed to assess the magnitude of failed induction of labor and associated factors among mothers delivered in Eastern Ethiopia.

METHODS

An institutional-based cross-sectional study was carried out among 364 women who had induction of labor at Jigjiga University, Sheik Hassan Yabare Referral Hospital from 2018 to 2021. A checklist was used to collect the data from the women's chart. To isolate independent predictors related to failed induction of labor, multivariate logistic regression analyses were performed.

RESULT

The magnitude of failed induction of labor was 36.8% (95% CI: 31.8, 42.0). Age (AOR = 3.2; CI: 1.78, 5.75), rural residency (AOR = 2.28; CI:1.29, 4.01), para (AOR = 2.76; CI: 1.55, 4.91), gestational age (AOR = 2.65; CI: 1.44, 4.89), multiple pregnancy (AOR = 2.36; CI: 1.01, 5.55), premature rapture of membrane (AOR = 4.88; CI: 2.33, 10.21), pregnancy-induced hypertension (AOR = 5.11; CI: 2.67, 9.79), and bishop score (AOR = 1.95; CI: 1.15, 3.32) were significantly associated with failed induction of labor.

CONCLUSION

The magnitude of failed induction of labor was relatively high in the study setting. Failed induction of labor was significantly associated with age, rural residency, primipara, gestational age, multiple pregnancy, premature rapture of membrane, PIH, and bishop score less than six. Prior to initiating the induction of labor, proper pelvis assessment and cervical ripening for bishop score might be considered. Beside to this, adherence to locally available induction protocols and guidelines might also be needed.

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.

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.

Factors Predicting Successful Vaginal Delivery Following Induction of Labor in Term Pregnancy

PURPOSE

This study was proposed to evaluate factors predicting a successful vaginal delivery following labor induction and develop induction prediction model in term pregnancy among Thai pregnant women.

PATIENTS AND METHODS

We conducted a retrospective cohort study using electronic medical records of 23,833 deliveries from April 2010 to July 2021 at tertiary care university hospital in Bangkok, Thailand. Univariate regression was performed to identify the association of individual parameters to successful vaginal delivery. Multiple logistic regression analysis of all possible variables from univariate analysis was performed to develop a prediction model with statistically significant of p value <0.05.

RESULTS

Of the total 809 labor-induced pregnancies, the vaginal delivery rate was 56.6%. Among predicting variables, history of previous vaginal delivery (aOR 5.75, 95% CI 3.701-8.961), maternal delivery BMI <25 kg/m² (aOR 2.010, 95% CI 1.303-3.286), estimated fetal weight <3500 g (aOR 2.193, 95% CI 1.246-3.860), and gestational age ≤39 weeks (aOR 1.501, 95% CI 1.038-2.173) significantly increased the probability of a successful vaginal delivery following labor induction. The final prediction model has been internally validated. Model calibration and discrimination were satisfactory with Hosmer-Lemeshow test P = 0.21 and with AUC of 0.756 (95% CI 0.695-0.816).

CONCLUSION

This study determined the pragmatic predictors for successful vaginal delivery following labor induction comprised history of previous vaginal delivery, maternal delivery BMI <25 kg/m², estimated fetal weight <3500 g, and gestational age ≤39 weeks. The final induction prediction model was well-performing internally validated prediction model to estimate individual probability when undergoing induction of labor. Despite restricted population, the predicting factors and model could be useful for further prospective study and clinical practice to improve induction outcomes.

Prevalence and factors associated with failed induction of labor in Worabe Comprehensive Specialized Hospital, Southern Ethiopia

Background

Induction of labor is one of the most used obstetric procedures in the world. It is performed in around 20% of all pregnancies. Failed induction of labor, on the other hand, has been associated with poorer mother and newborn health outcomes. Besides, there is a scarcity of data on the current burden and drivers. Therefore, this study aimed to assess the prevalence and factors associated with failed induction in Worabe Comprehensive Specialized Hospital, Southern Ethiopia.

Methods

A retrospective cross-sectional study was conducted on medical records of mothers who delivered through induction of labor during September 1^st, 2018 to August 30^th, 2020. The samples were collected using a systematic sampling technique. The data was extracted using a checklist. Data were entered into EpiData (version 3.1) and analyzed using SPSS (version 24). Multivariable logistic regression analyses were used to decide the association of explanatory variables with the outcome variable. Odds ratio with their 95% CI were calculated to identify the presence and strength of an association. A p-value of < 0.05 was used to declare statistical significance.

Results

In this study, the prevalence of failed induction was observed to be 22.2%. The associated factors included rural residence (AOR = 5.7, 95% CI: 3.12–11.02), primiparity (AOR = 8.4, 95% CI: 2.72–22.36) and unfavourable bishop score (AOR = 5.9, 95% CI: 4.52–16.12).

Conclusions

In comparison to the rate reported in developed countries, the study area had a high rate of failed induction. Being rural residence, primiparity and unfavourable bishop score were the associated factors of failed induction. Therefore, to reduce of the rate of failed induction, health care practitioners should analyze cervical status (using Bishop Score) to decide the possibility of successful induction, with a focus on associated factors like parity.

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.

Misoprostol for labour induction

Oral and vaginal misoprostol are effective induction methods, but there is a delicate balance between a quicker labour and avoiding side effects. In randomised comparisons with balloon catheters, oral misoprostol resulted in more vaginal births in the first 24 h as well as fewer caesarean sections without an increase in hyperstimulation events. Vaginal misoprostol was most effective when used concurrently with a balloon catheter. In comparison with dinoprostone, oral misoprostol had lower rates of caesarean section and uterine hyperstimulation with foetal heart rate changes, but fewer babies were born vaginally within 24 h. In contrast, vaginal misoprostol resulted in more vaginal births within 24 h, with no significant differences in caesarean section rates. There were no differences in perinatal adverse events with either route. When oral and vaginal misoprostol were compared, vaginal misoprostol resulted in more vaginal births in the first 24 h, but with more maternal and neonatal complications.

A Peripheral Immune Signature of Labor Induction

Approximately 1 in 4 pregnant women in the United States undergo labor induction. The onset and establishment of labor, particularly induced labor, is a complex and dynamic process influenced by multiple endocrine, inflammatory, and mechanical factors as well as obstetric and pharmacological interventions. The duration from labor induction to the onset of active labor remains unpredictable. Moreover, prolonged labor is associated with severe complications for the mother and her offspring, most importantly chorioamnionitis, uterine atony, and postpartum hemorrhage. While maternal immune system adaptations that are critical for the maintenance of a healthy pregnancy have been previously characterized, the role of the immune system during the establishment of labor is poorly understood. Understanding maternal immune adaptations during labor initiation can have important ramifications for predicting successful labor induction and labor complications in both induced and spontaneous types of labor. The aim of this study was to characterize labor-associated maternal immune system dynamics from labor induction to the start of active labor. Serial blood samples from fifteen participants were collected immediately prior to labor induction (baseline) and during the latent phase until the start of active labor. Using high-dimensional mass cytometry, a total of 1,059 single-cell immune features were extracted from each sample. A multivariate machine-learning method was employed to characterize the dynamic changes of the maternal immune system after labor induction until the establishment of active labor. A cross-validated linear sparse regression model (least absolute shrinkage and selection operator, LASSO) predicted the minutes since induction of labor with high accuracy (R = 0.86, p = 6.7e-15, RMSE = 277 min). Immune features most informative for the model included STAT5 signaling in central memory CD8⁺ T cells and pro-inflammatory STAT3 signaling responses across multiple adaptive and innate immune cell subsets. Our study reports a peripheral immune signature of labor induction, and provides important insights into biological mechanisms that may ultimately predict labor induction success as well as complications, thereby facilitating clinical decision-making to improve maternal and fetal well-being.

Induction of labour in low-resource settings

Due to the disparity in resource availability between low- and high-resource settings, practice recommendations relevant to high-income countries are not always relevant and often need to be adapted to low-resource settings. The adaptation applies to induction of labour (IOL) which is an obstetric procedure that deserves special attention because it involves the initiation of a process that requires regular and frequent monitoring of the mother and foetus by experienced healthcare professionals. Lack of problem recognition and/or substandard care during IOL may result in harm with long-term sequelae. In this article, the authors discuss unique challenges such as insufficient resources (including staff, midwives, doctors, equipment, and medications) that result in occasional inadequate patient monitoring and/or delayed interventions during IOL in low-resource settings. We also discuss modifications in indications and methods for IOL, issues related to human immunodeficiency virus (HIV) infections, the feasibility of outpatient induction, clinical protocols and a minimum dataset for quality improvement projects. Overall, the desire to achieve a vaginal birth with IOL should not cloud the necessity to observe the required safety measures and implement necessary interventions; given that childbirth practices are the major determinants of pregnancy outcomes and patient satisfaction.

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.

The usefulness of ultrasound before induction of labor

The indications for induction of labor have been consistently on the rise. These indications are mainly medical (maternal or fetal) or social or related to convenience or maternal preferences. With the increase in the prevalence of these indications, the incidence rates of induction of labor are expected to rise continuously. This poses a substantial workload and financial burden on maternity healthcare systems. Failure rates of induction of labor are relatively high, especially when considering the maternal, fetal, and neonatal risks associated with emergency cesarean deliveries in cases of failure. Therefore, it is essential for obstetricians to carefully select women who are eligible for induction of labor, particularly those with no clinical contraindication and who have a reasonable chance of ending up with a successful noncomplicated vaginal delivery. Ultrasound has an established role in the various areas of obstetrical care. It is available, accessible, easy to perform, and acceptable to the patient. In addition, the learning curve for skillful obstetrical ultrasound scanning is rather easy to fulfill. Ultrasound has always had an important role in the assessment of maternal and fetal well-being. Indeed, it has been extensively explored as a reliable, reproducible, and objective tool in the management of labor. In this review, we aimed to provide a comprehensive update on the different applications and uses of ultrasound before induction of labor for the prediction of its success and the potential improvement of its health-related maternal and fetal outcomes.

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.

The Uterocervical Angle Combined with Bishop Score as a Predictor for Successful Induction of Labor in Term Vaginal Delivery

The objective of this study was to determine the value of uterocervical angle (UCA) in predicting successful induction of labor (IOL) in singleton pregnant women compared to the Bishop score and cervical length (CL). A total of 205 normal term, singleton labor-induction cases were analyzed. Successful IOL was defined as the onset of active labor of induction. A comparative analysis was performed to evaluate the effectiveness of UCA, Bishop score, and CL in predicting IOL. Compared to the non-successful IOL group, the women in the successful IOL group had significantly wider UCA (p = 0.012) and higher Bishop score (p = 0.001); however, the CL was not significantly different (p = 0.130). UCA alone did not perform better than the Bishop score when predicting successful IOL. However, UCA combined with the Bishop score showed higher performance in predicting IOL (combined UCA > 108.4° and favorable Bishop score as sensitivity of 44.6%, specificity of 96.0%, PPV of 96.2%, and NPV of 43.6; combined UCA > 108.4° or favorable Bishop score as sensitivity of 85.7%, specificity of 50.0%, PPV of 78.7%, and NPV of 61.9). In conclusion, UCA combined with Bishop score may be an effective sonographic method for predicting successful IOL.

Failed induction of labor and its associated factors in Ethiopia: A systematic review and meta-analysis

Introduction

Failed induction increased maternal morbidity and mortality due to the associated complication which comes with cesarean section such as post partum hemorrhage and sepsis. The reports of previous articles on the proportion and associated factor of failed induction were variable and inconsistent. Therefore, this meta-analysis found out that the pooled proportion of failed induction and its associated factors in Ethiopia.

Methods

Systematic search was done by online databases (Pub Med, Web of Science, Google scholar and HINARI, and Ethiopian universities digital libraries). Unpublished studies that are found in the Ethiopian universities’ digital libraries were used for this systematic review and meta-analysis study. Data were entered into Microsoft Excel and then exported to STATA 11 version statistical software for analysis. Heterogeneity assessed using the I² statistic. The pooled proportion of failed induction and the odds ratio (OR) with a 95% confidence interval was showed using forest plots.

Result

The overall proportion of failed induction was 23.58 % (95% CI: 13.72–33.44). Unfavorable Bishop Score [OR = 4.45, 95CI:2.44,8.12 ] intermediate Bishop Score [OR = 8.87, 95CI:4.62,17.05 ] and being primiparous woman [OR = 3.04, 95CI:1.74,5.53 ] were factors associated with failed induction of labour.

Conclusion

The prevalence of failed induction was high in Ethiopia. Unfavorable Bishop Score, intermediate Bishop Score, and primiparous were significantly associated with failed induction. Proper pelvis assessment for Bishop Score will be considered prior to initiating the induction of labor. Beside to this, the health professionals shall be aware of the relevance of cervical ripening for intermediate and unfavorable Bishop Score for pregnant women's before induction of labor.

Safety and efficacy of an oral misoprostol standard-dose regimen vs a low-dose regimen for induction of labour in Papua New Guinean women: An open-label randomised controlled trial

BACKGROUND

Oral misoprostol is widely used for induction of labour (IOL) in developing countries because of its many advantages. However, limited data exist concerning its safety and efficacy when lower doses are used.

AIM

To determine the safety and efficacy of a low-dose oral misoprostol regimen (commencing at 12 μg) compared to a standard-dose regimen (commencing at 25 μg) in Papua New Guinea (PNG) women undergoing IOL.

MATERIALS AND METHODS

This was an open-label non-inferiority randomised controlled trial conducted at a provincial hospital in PNG. Women with singleton pregnancies ≥36 weeks with cephalic presentation and a Bishops score of <6, requiring IOL were enrolled. Both regimens were incremented second-hourly to a maximum required dose within 24 h or until commencement of labour. The primary outcome was the proportion of women who delivered within 24 h of drug administration without any severe adverse events.

RESULTS

Of the 262 women induced (130 standard-dose vs 132 low-dose), rates of successful induction were high for both regimens (120/130 (92%) vs 118/132 (89%); P = 0.52). Fourteen women (11%) in the standard-dose regimen and 20 (15%) in the low-dose regimen had severe adverse events. There was no significant difference in the safety profile of the two regimens (106/130 (82%) vs 98/132 (74%); P = 0.18). The induction-to-delivery time was significantly shorter in the standard-dose arm (15.2 ± 8.7 h vs 18.0 ± 9.1 h; P = 0.01).

CONCLUSION

The standard-dose regimen for IOL has greater efficacy in reducing induction-to-delivery time compared to the low-dose regimen. There was no significant difference in the number of adverse events between the two regimens.

Development and validation of a model for individualized prediction of cervical insufficiency risks in patients undergoing IVF/ICSI treatment

BACKGROUND

Women who conceived with in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) are more likely to experience adverse pregnancy outcomes than women who conceived naturally. Cervical insufficiency (CI) is one of the important causes of miscarriage and premature birth, however there is no published data available focusing on the potential risk factors predicting CI occurrence in women who received IVF/ICSI treatment. This study aimed to identify the risk factors that could be integrated into a predictive model for CI, which could provide further personalized and clinically specific information related to the incidence of CI after IVF/ICSI treatment.

PATIENTS AND METHODS

This retrospective study included 4710 patients who conceived after IVF/ICSI treatment from Jan 2011 to Dec 2018 at a public university hospital. The patients were randomly divided into development (n = 3108) and validation (n = 1602) samples for the building and testing of the nomogram, respectively. Multivariate logistic regression was developed on the basis of pre-pregnancy clinical covariates assessed for their association with CI occurrence.

RESULTS

A total of 109 patients (2.31%) experienced CI among all the enrolled patients. Body mass index (BMI), basal serum testosterone (T), gravidity and uterine length were associated with CI occurrence. The statistical nomogram was built based on BMI, serum T, gravidity and uterine length, with an area under the curve (AUC) of 0.84 (95% confidence interval: 0.76-0.90) for the developing cohort. The AUC for the validation cohort was 0.71 (95% confidence interval: 0.69-0.83), showing a satisfactory goodness-of-fit and discrimination ability in this nomogram.

CONCLUSION

The user-friendly nomogram which graphically represents the risk factors and a pre-pregnancy predicted tool for the incidence of CI in patients undergoing IVF/ICSI treatment, provides a useful guide for medical staff on individualized decisions making, where preventive measures could be carried out during the IVF/ICSI procedure and subsequent pregnancy.

Clinical and ultrasonographic parameters in assessment of labor induction success in nulliparous women

Purpose: Evaluation of simplified Bishop score and ultrasound cervicometry in the assessment of labor induction success in nulliparous women.Methods: Prospective cohort study included 146 nulliparous women with singleton pregnancy and indications for labor induction. Prior to labor induction, cervicometry and Bishop score were determined. Upon delivery, patients were classified as those delivered vaginally and by cesarean section (CS) after unsuccessful labor induction.Results: Bishop score >5 was found in 47.95% of vaginally delivered women and 12.33% of patients delivered by CS (p < .01). Cervicometry had appropriate findings in 34.2% of vaginally delivered women and 75.3% of those delivered by CS (p < .01). Bishop score (>5 versus ≤5) had lower sensitivity (52.05%) and specificity (12.33%) than cervicometry (good versus unfavorable findings) (sensitivity 65.75%, specificity 75.34%) for prediction of labor induction success. If Bishop score was ≤5, cervicometry had 50.0% sensitivity and 78.13% specificity, while if Bishop score was >5, 82.86% sensitivity and 55.56% specificity. Obtained model for predicting labor induction outcome in nulliparous women based on their clinical and ultrasonographical characteristics identified the Bishop score as the most important predictor.Conclusions: Study confirmed the usefulness of simplified Bishop score and ultrasound cervicometry in the assessment of labor induction success in nulliparous women.

Factors associated with delayed onset of active labor following vaginal misoprostol administration among women at Mbarara Regional Referral Hospital, Uganda

OBJECTIVE

To determine the factors associated with delayed onset of active labor following labor induction with vaginal misoprostol.

METHODS

We conducted a prospective cohort study over 6 months at a tertiary hospital in Uganda. We enrolled mothers with pregnancies of at least 28 weeks, who were undergoing labor induction with 50 µg of vaginal misoprostol, administered every 6 hours with a maximum of four doses, and followed them up until onset of active labor. Labor onset was considered delayed if it occurred later than 12 hours after the first dose. Bivariate and multivariate analysis was performed to determine factors associated with delayed onset of active labor.

RESULTS

Of the 88 mothers enrolled, 22.7% (n=20) had delayed onset of active labor. Nulliparity (adjusted relative risk [aRR] 2.34, 95% confidence interval [CI] 1.17-4.68) and gestational age less than 37 weeks (aRR 3.79, 95% CI 1.40-10.23) were associated with delayed onset of active labor following vaginal misoprostol administration whereas higher body mass index (aRR 0.38, 95% CI 0.18-0.79) decreased the risk.

CONCLUSION

Delayed onset of active labor following labor induction remains an important obstetric care challenge. Mothers undergoing labor induction should have their body mass index documented, and nulliparous women and mothers at less than 37 weeks of gestation should have their labor monitored for a longer duration following labor induction.

Reliability of strain elastography using in vivo compression in the assessment of the uterine cervix during pregnancy

Objective To determine the reproducibility of the mean strain value in various cervical areas and new elastographic parameters for measuring cervical stiffness evaluated by strain elastography using in vivo compression generated by internal organ movement. Methods A prospective observational study (140 singleton pregnant women; 15-33 weeks of gestation) was performed at two tertiary centers. Cervical strain was evaluated using E-cervix™ elastography. The mean strain levels of various cervical areas [internal os (IOS), external os (EOS) and endocervical area] and several new parameters [i.e. the ratio of the strain level of IOS and EOS, elasticity contrast index (ECI), and hardness ratio] were assessed twice by two independent examiners. The inter-observer and intra-observer variances were calculated using the intraclass correlation coefficient (ICC) with a 95% confidence interval (CI). Bland-Altman (B-A) analysis was also performed. Results The median gestational age was 24.0 weeks, and the mean cervical length (CL) was 3.8 cm. The intra-observer and inter-observer ICCs of the mean strain levels of the specified cervical area and new elastographic parameters were statistically significant (P < 0.001, all); the intra-observer ICC was 0.639-0.725, and the inter-observer ICC was 0.538-0.718. Conclusion The reproducibility of elastographic parameter measurements using in vivo compression is improvable.

Genetic landscape of preterm birth due to cervical insufficiency: Comprehensive gene analysis and patient next-generation sequencing data interpretation

Preterm delivery is both a traumatizing experience for the patient and a burden on the healthcare system. A condition distinguishable by its phenotype in prematurity is cervical insufficiency, where certain cases exhibit a strong genetic component. Despite genomic advancements, little is known about the genetics of human cervix remodeling during pregnancy. Using selected gene approaches, a few studies have demonstrated an association of common gene variants with cervical insufficiency. However, until now, no study has employed comprehensive methods to investigate this important subject matter. In this study, we asked: i) are there genes reliably linked to cervical insufficiency and, if so, what are their roles? and ii) what is the proportion of cases of non-syndromic cervical insufficiency attributable to these genetic variations? We performed next-generation sequencing on 21 patients with a clinical presentation of cervical insufficiency. To assist the sequencing data interpretation, we retrieved all known genes implicated in cervical functioning through a systematic literature analysis and additional gene searches. These genes were then classified according to their relation to the questions being posed by the study. Patients' sequence variants were filtered for pathogenicity and assigned a likelihood of being contributive to phenotype development. Gene extraction and analysis revealed 12 genes primarily linked to cervical insufficiency, the majority of which are known to cause collagenopathies. Ten patients carried disruptive variants potentially contributive to the development of non-syndromic cervical insufficiency. Pathway enrichment analysis of variant genes from our cohort revealed an increased variation burden in genes playing roles in tissue mechanical and biomechanical properties, i.e. collagen biosynthesis and cell-extracellular matrix communications. Consequently, the proposed idea of cervical insufficiency being a subtle form of collagenopathy, now strengthened by our genetic findings, might open up new opportunities for improved patient evaluation and management.

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.

Immunobiology of Cervix Ripening

The cervix is the essential gatekeeper for birth. Incomplete cervix remodeling contributes to problems with delivery at or post-term while preterm birth is a major factor in perinatal morbidity and mortality in newborns. Lack of cervix biopsies from women during the period preceding term or preterm birth have led to use of rodent models to advanced understanding of the mechanism for prepartum cervix remodeling. The critical transition from a soft cervix to a compliant prepartum lower uterine segment has only recently been recognized to occur in various mammalian species when progesterone in circulation is at or near the peak of pregnancy in preparation for birth. In rodents, characterization of ripening resembles an inflammatory process with a temporal coincidence of decreased density of cell nuclei, decline in cross-linked extracellular collagen, and increased presence of macrophages in the cervix. Although a role for inflammation in parturition and cervix remodeling is not a new concept, a comprehensive examination of literature in this review reveals that many conclusions are drawn from comparisons before and after ripening has occurred, not during the process. The present review focuses on essential phenotypes and functions of resident myeloid and possibly other immune cells to bridge the gap with evidence that specific biomarkers may assess the progress of ripening both at term and with preterm birth. Moreover, use of endpoints to determine the effectiveness of various therapeutic approaches to forestall remodeling and reduce risks for preterm birth, or facilitate ripening to promote parturition will improve the postpartum well-being of mothers and newborns.

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.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Accuracy of the Manipal Cervical Scoring System for predicting successful induction of labour

The Manipal Cervical Scoring System is an accurate and objective sonographic score that predicts the outcome of induced labour. The aim of the current study was to compare the performance of the Manipal Cervical Scoring System against the Bishop Score. A prospective study was conducted on 105 women underwent labour induction in Ain Shams University Hospital, Cairo, Egypt. Both scores were assessed pre-induction. Successful induction occurred in 78.09% of the cases. The area under the ROC curve (AUC) was of 0.940 (95% CI = 0.876 to 0.977; p value <.0001) for the Manipal Score and 0.863 (95% CI = 0.783-0.923; p value <.0001) for the Bishop Score. The Manipal Score >5 had a sensitivity of 91.5% and a specificity of 91.3%. While the Bishop score >4 had a sensitivity of 98.8% and specificity of 69.6% to predict the outcome of induced labour. The Manipal Cervical Scoring system is a better objective tool to predict the outcome of labour induction compared to the Bishop Score. However, other female and fetal characteristics, including body mass index (BMI) at gestation, gestational weight gain, occiput position and parity should be taken into consideration when performing labour induction. Impact statement What is already known on this subject? The ultimate fate of 20% of women having an induction of labour (IOL) is a Caesarean delivery. Thus, predicting the possible response to IOL before starting induction could guide clinicians to determine the efficacy of starting and/or continuing the induction process and in counselling women regarding the possible response to IOL. The main predictor for IOL outcome is based on the pre-induction cervical status which has been traditionally assessed by the Bishop Score. However, the Bishop Score remains subjective, thereby, associated with high rates of bias and several studies have demonstrated its poor predictive value for the outcome of induction. What do the results of this study add? Proposed use of ultrasound parameters that are equivalent to Bishop Score will be objective, reliable and reproducible method. It allows for patient re-evaluation by other obstetricians without the need for re-examination (thus decreasing exposing the patient to pain and anxiety). What are the implications of these findings for clinical practice and/or further research? According to WHO and FIGO, oral misoprostol (25 μg, 2-hourly) is recommended for induction of labour. This helps to decrease the discomfort of repeated vaginal examination and increases the women satisfaction with labour process, especially in women at higher risk of infection. Thus evaluating cervical status using an ultrasound cervical scoring system can similarly increase women's satisfaction with labour process. Our goal in the upcoming trial is to perform RCT comparing ultrasound versus Bishop in women undergoing IOL using oral misopristol regarding measures of satisfaction during labour in the parturient women.

Clinical and Sonographic Model to Predict Cesarean Delivery after Induction of Labor at Term

OBJECTIVE

To develop a model combining clinical and sonographic features to predict the risk of cesarean delivery after the induction of labor (IOL).

METHODS

We designed a prospective observational study involving women admitted for IOL. The main outcome was defined as cesarean delivery due to failed IOL or arrest of labor. Several clinical and ultrasonographic variables were collected. Seventy percent of the sample was used to build the predictive model, using stepwise logistic regression, while the remaining sample was used for validation. The final model was estimated and calibrated using all participants.

RESULTS

We analyzed 477 pregnancies. The main outcome occurred in 102/477 (21.4%) women. The final model included previous vaginal delivery (odds ratio [OR] 0.088; 95% confidence interval [CI] 0.04-0.21), height (OR 0.904; 95% CI 0.87-0.94), body mass index before delivery (OR 1.084; 95% CI 1.02-1.15), ultrasonographic estimated fetal weight (OR 3.965; 95% CI 2.18-7.22), and ultrasonographic cervical length (OR 1.065; 95% CI 1.04-1.09) as predictors. Area under the receiver operating characteristics curve was 0.826 (95% CI 0.78-0.87). For a 5% false-positive rate, the sensitivity, specificity, and positive and negative likelihood ratios were 44.1%, 94.9%, 8.7, and 0.59, respectively.

CONCLUSION

Our model combining clinical and ultrasonographic features might offer individualized counseling regarding risk of cesarean delivery to women who are candidates for IOL.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

Defining failed induction of labor

BACKGROUND

While there are well-accepted standards for the diagnosis of arrested active-phase labor, the definition of a "failed" induction of labor remains less certain. One approach to diagnosing a failed induction is based on the duration of the latent phase. However, a standard for the minimum duration that the latent phase of a labor induction should continue, absent acute maternal or fetal indications for cesarean delivery, remains lacking.

OBJECTIVE

The objective of this study was to determine the frequency of adverse maternal and perinatal outcomes as a function of the duration of the latent phase among nulliparous women undergoing labor induction.

STUDY DESIGN

This study is based on data from an obstetric cohort of women delivering at 25 US hospitals from 2008 through 2011. Nulliparous women who had a term singleton gestation in the cephalic presentation were eligible for this analysis if they underwent a labor induction. Consistent with prior studies, the latent phase was determined to begin once cervical ripening had ended, oxytocin was initiated, and rupture of membranes had occurred, and was determined to end once 5-cm dilation was achieved. The frequencies of cesarean delivery, as well as of adverse maternal (eg, postpartum hemorrhage, chorioamnionitis) and perinatal (eg, a composite frequency of seizures, sepsis, bone or nerve injury, encephalopathy, or death) outcomes, were compared as a function of the duration of the latent phase (analyzed with time both as a continuous measure and categorized in 3-hour increments).

RESULTS

A total of 10,677 women were available for analysis. In the vast majority (96.4%) of women, the active phase had been reached by 15 hours. The longer the duration of a woman's latent phase, the greater her chance of ultimately undergoing a cesarean delivery (P < .001, for time both as a continuous and categorical independent variable), although >40% of women whose latent phase lasted ≥18 hours still had a vaginal delivery. Several maternal morbidities, such as postpartum hemorrhage (P < .001) and chorioamnionitis (P < .001), increased in frequency as the length of latent phase increased. Conversely, the frequencies of most adverse perinatal outcomes were statistically stable over time.

CONCLUSION

The large majority of women undergoing labor induction will have entered the active phase by 15 hours after oxytocin has started and rupture of membranes has occurred. Maternal adverse outcomes become statistically more frequent with greater time in the latent phase, although the absolute increase in frequency is relatively small. These data suggest that cesarean delivery should not be undertaken during the latent phase prior to at least 15 hours after oxytocin and rupture of membranes have occurred. The decision to continue labor beyond this point should be individualized, and may take into account factors such as other evidence of labor progress.

The value of ultrasound measurement of cervical length and parity in prediction of cesarean section risk in term premature rupture of membranes and unfavorable cervix

AIM

To evaluate the influence of cervical length (CL) and parity as prediction factors for assessment of cesarean section (CS) risk in women with premature rupture of membranes (PROM) at term and unfavorable cervix, undergoing induction of labor (IOL) with dinoprostone intracervical gel.

METHODS

A prospective study involved 50 nulliparous and 51 multiparous women admitted for IOL. Pre-induction CL was measured and delivery outcomes were recorded.

RESULTS

Nulliparous women were younger than the multiparous (26.6±5.2 vs. 30.5±4.9; P<0.001) and had longer pre-induction CL (35.6±5.5 vs. 31.5±4.8; P<0.001) and induction-delivery interval (582 vs. 420 min; P<0.001). There was no difference in the mode of delivery, CS indications, Apgar score, neonatal weight, the rate of neonatal intensive care unit admission and perinatal death in respect of parity. CL was significantly shorter in vaginal vs. cesarean deliveries regardless of parity (31.4 vs. 38.8 mm, P<0.001, respectively). Cut-off values of CL for predicting CS were 37.5 mm in nulliparae and 34.5 mm in multiparae.

CONCLUSIONS

CLs of 37.5 mm in nulliparae and 34.5 mm in multiparae were determined as the cut-off values in predicting CS risk in women with PROM at term and unfavorable cervix.

Initial clinical experience with a misoprostol vaginal insert in comparison with a dinoprostone insert for inducing labor

OBJECTIVE

Only one phase III trial has been published to date on the efficacy and safety of misoprostol vaginal inserts for inducing labor. The aim of this study was to compare misoprostol inserts with dinoprostone inserts.

STUDY DESIGN

This retrospective cohort study evaluated the reduction in time to vaginal delivery and delivery within 24h, in routine clinical work, in 119 labor inductions using a 200-μg misoprostol vaginal insert (Misodel(®); June-October 2014) in comparison with 124 inductions using a 10-mg dinoprostone insert (Propess(®); December 2013-April 2014).

RESULTS

Vaginal delivery within 24h occurred in 77.3% (n=92) of the misoprostol cohort and 74.2% (n=92) of the dinoprostone cohort (P=0.654). Time from insert application to vaginal delivery (min) was 761.76 (±409.44, cohort M) versus 805.17 (±473.00, cohort D) (P=0.817). Cesarean delivery was performed in 10.1% (n=12) versus 10.5% (n=13) in the misoprostol and dinoprostone cohorts, respectively (P≥0.999). The modified Bishop scores were 2.0 versus 3.0 (P=0.001), mean body mass index (BMI) was 24.72 versus 23.95 (P=0.033), and fetal scalp blood testing was required in 12.6% (n=15) versus 3.2% (n=4; P=0.008). No differences were observed with regard to the rates of transfer to the neonatal unit or any type of fetal acidosis.

CONCLUSIONS

The groups thus had similar results for rates of vaginal delivery within 24h, cesarean delivery and fetal outcomes. The misoprostol group had lower modified Bishop scores, higher BMIs, and a higher rate of fetal scalp blood testing.