Predictors of Induction Success

doi:10.1053/j.semperi.2012.04.017

Seminars in Perinatology

Volume 36, Issue 5, October 2012, Pages 344-347

https://doi.org/10.1053/j.semperi.2012.04.017 Get rights and content

If the prediction of induction success is to be used as a tool to lower the frequency of a first cesarean delivery, such prediction would need to be among women who are undergoing elective induction, and would need to indicate which women are more likely to have cesarean if they are induced as opposed to expectantly managed. This review summarizes the data that link elective labor induction and cesarean delivery, as well as the factors (or lack thereof) that may be used to better understand which women who are induced ultimately have a vaginal delivery.

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Cited by (38)

A predictive model for successfully inducing active labor among pregnant women: Combining cervical status assessment and clinical characteristics
2023, European Journal of Obstetrics and Gynecology and Reproductive Biology: X
To develop a predictive model for successfully inducing active labor by using a combination of cervical status and maternal and fetal characteristics.
A retrospective cohort study was conducted among pregnant women who underwent labor induction between January 2015 and December 2019. Successfully inducing active labor was defined as achieving a cervical dilation > 4 cm within 10 h after adequate uterine contractions. The medical data were extracted from the hospital database; statistical analyses were performed using a logistic regression model to identify the predictors associated with the successful induction of labor. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to assess the accuracy of the model.
In total, 1448 pregnant women were enrolled; 960 (66.3 %) achieved successful induction of active labor. Multivariate analysis revealed that maternal age, parity, body mass index, oligohydramnios, premature rupture of membranes, fetal sex, dilation, station, and consistency were significant factors associated with successful labor induction. The ROC curve of the logistic regression model had an AUC of 0.7736. For the validated score system to predict the probability of success, we found that a total score > 60 has a 73.0 % (95 % CI 59.0–83.5) probability of successful induction of labor into the active phase stage within 10 h.
The predictive model for successfully achieving active labor using the combination of cervical status and maternal and fetal characteristics had good predictive ability.
Reducing the cesarean delivery rate
2021, European Journal of Obstetrics and Gynecology and Reproductive Biology
Citation Excerpt :
On one hand, there are meta-analyses recognizing the possibly reduced cesarean risk with IOL compared with expectant management, [8,9,10,11,12,13] yet studies counter to that have been published, comparing IOL with spontaneous labor (SL) [14–18]. Certainly, various predictors exist for successful IOL, including the Bishop score, representing the cervical status indicating the potential for SL [19]. With IOL, a greater time may be spent in the latent phase of labor, which is another factor that can contribute to whether vaginal delivery successfully occurs [13].
The cesarean delivery rate has been rising in recent years, having associated maternal morbidities. Elective induction of labor has also been seen to rise during this same time period.
This current study investigated the difference in the cesarean delivery rate between induction of labor and spontaneous labor among nulliparous, term, singleton, and vertex-presenting women.
A retrospective cohort in a single institution over a seven-year period was used for this analysis, observing the difference in cesarean delivery rate at different term gestational ages and neonatal morbidity using the 5-minute Apgar score < 5.
A statistically significant difference was found in cesarean delivery rate between those women whose labor was induced and those whose labor began spontaneously, at each term gestational age of labor initiation (P < 0.001). The proportion of indications for induction was described (i.e. elective vs. medically-indicated), and no difference was found for neonatal morbidity between the groups analyzed, using the 5-minute Apgar score as the perinatal outcome measure.
A comparison was made between spontaneous and induced labor regarding the resultant cesarean delivery rate, and a significant difference was found favoring spontaneous labor. This should be considered when electing to deliver using an induction methodology for nulliparous women, especially when there are no medical indications for it.
A validated calculator to estimate risk of cesarean after an induction of labor with an unfavorable cervix
2018, American Journal of Obstetrics and Gynecology
Citation Excerpt :
Results from the calculator should not be used to forego an induction when it is medically indicated, to lower the threshold for elective primary cesarean delivery, or to lower the threshold for cesarean delivery in labor in the absence of other clinical information. The characteristics that we identified as risk factors for cesarean delivery have been previously reported in the literature3-8; however, they have not been compiled in a risk model that estimates the percent likelihood of cesarean based on those factors. Our study differs from the current literature by including both nulliparous and multiparous women as well as including only women whose starting cervical exam is unfavorable (cervical dilation ≤2 cm and Bishop score ≤6).
Induction of labor occurs in >20% of pregnancies, which equates to approximately 1 million women undergoing an induction in the United States annually. Regardless of how common inductions are, our ability to predict induction success is limited. Although multiple risk factors for a failed induction have been identified, risk factors alone are not enough to quantify an actual risk of cesarean for an individual woman undergoing a cesarean.
The objective of this study was to derive and validate a prediction model for cesarean after induction with an unfavorable cervix and to create a Web-based calculator to assist in patient counseling.
Derivation and validation of a prediction model for cesarean delivery after induction was performed as part of a planned secondary analysis of a large randomized trial. A predictive model for cesarean delivery was derived using multivariable logistic regression from a large randomized trial on induction methods (n = 491) that took place from 2013 through 2015 at an academic institution. Full-term (≥37 weeks) women carrying a singleton gestation with intact membranes and an unfavorable cervix (Bishop score ≤6 and dilation ≤2 cm) undergoing an induction were included in this trial. Both nulliparous and multiparous women were included. Women with a prior cesarean were excluded. Refinement of the prediction model was performed using an observational cohort of women from the same institution who underwent an induction (n = 364) during the trial period. An external validation was performed utilizing a publicly available database (Consortium for Safe Labor) that includes information for >200,000 deliveries from 19 hospitals across the United States from 2002 through 2008. After applying the same inclusion and exclusion criteria utilized in the derivation cohort, a total of 8466 women remained for analysis. The discriminative power of each model was assessed using a bootstrap, bias-corrected area under the curve.
The cesarean delivery rates in the derivation and external validation groups were: 27.7% (n = 136/491) and 26.4% (n = 2235/8466). In multivariable modeling, nulliparity, gestation age ≥40 weeks, body mass index at delivery, modified Bishop score, and height were significantly associated with cesarean. A nomogram and calculator were created and found to have an area under the curve in the external validation cohort of 0.73 (95% confidence interval, 0.72–0.74).
A nomogram and user-friendly Web-based calculator that incorporates 5 variables known at the start of induction has been developed and validated. It can be found at: http://www.uphs.upenn.edu/obgyn/labor-induction-calculator/. This calculator can be used to augment patient counseling for women undergoing an induction with an unfavorable cervix.
Predictors of perinatal outcomes and economic costs for late-term induction of labour
2017, Taiwanese Journal of Obstetrics and Gynecology
We aimed to predict the perinatal outcomes and costs of health services following labour induction for late-term pregnancies.
We conducted a cohort study of 245 women who underwent labour induction during their 41st week of gestation. The cervical condition was assessed upon admission using the Bishop score and ultrasound cervical length measurements. We estimated the direct costs of labour induction, and a predictive model for perinatal outcomes was constructed using the decision tree analysis algorithm and a logit model.
A very unfavourable Bishop score at admission (Bishop score <2) (OR, 3.43 [95% CI, 1.77–6.59]), and a history of previous caesarean section (OR, 7.72 [95% CI, 2.43–24.43]) or previous vaginal delivery (OR, 0.24 [95% CI, 0.09–0.58]) were the only variables with predictive capacity for caesarean section in our model. The mean cost of labour induction was €3465.56 (95% confidence interval [CI], 3339.53–3591.58). Unfavourable Bishop scores upon admission and no history of previous deliveries significantly increased the cost of labour induction. Both of these criteria significantly predicted the likelihood of a caesarean section in the decision tree analysis.
The cost of labour induction mostly depends on the likelihood of successful trial of labour. Combined use of the Bishop score and previous vaginal or caesarean deliveries improves the ability to predict the likelihood of a caesarean section and the economic costs associated with labour induction for late-term pregnancies. This information is useful for patient counselling.
Balloon catheters for induction of labor at term after previous cesarean section: a systematic review
2016, European Journal of Obstetrics and Gynecology and Reproductive Biology
Citation Excerpt :
For all patients, attempting vaginal birth after cesarean section (VBAC), the success rates range from 60 to 85% [3], however, dramatic reduction of TOLAC has been observed after reports of worrying increase in rupture-associated severe perinatal outcome (e.g., hypoxic-ischemic encephalopathy) and also in severe maternal complications (e.g., severe postpartum hemorrhage, hysterectomy) [4–6]. This increase in short-term morbidity must be balanced by the increase in maternal and neonatal risk associated with multiple repeat cesarean sections [7–11]. It is not clear whether all induction agents have been associated with the same magnitude of increased risk of uterine rupture in the setting of TOLAC [4,12].
To systematically review the application of balloon catheters for cervical ripening and labor induction at term after previous cesarean section.
All pregnancies at term with previous cesarean section were included when cervical ripening or labor induction was conducted with balloon catheters. MEDLINE, Cochrane database and bibliography of identified articles were searched for English language studies. Reviews and meta-analysis, randomized and non-randomized controlled trials, prospective and retrospective cohort studies as well as case-control studies were considered.
A total of 48 potentially relevant studies were identified. The title and abstract were screened for eligibility and 32 articles were excluded. The remaining 16 publications included 1447 women (single-balloon catheter: n = 1329, double-balloon catheter: n = 118). There were no randomized controlled trials. Most of the trials were retrospective studies (n = 10). The rate of uterine rupture after labor induction was low (n = 18, 1.2%). Meta-analysis of studies comparing the risk of uterine rupture between labor induction and spontaneous onset of labor found a higher risk after induction (OR 2.45, 95%CI 1.34–4.47, NNH 186). The average rate of oxytocin application was 68.4%, and vaginal birth was achieved in 56.4%. The risk for cesarean delivery was higher when labor was induced (OR 2.63, 95%CI 2.24–3.10).
Data on balloon catheters for labor induction after previous cesarean section are limited by small sample size and retrospective analyses. The present data show a moderately increased risk for uterine rupture (OR = 2.45) compared to spontaneous onset of labor. However, for evidence based recommendations much more well-conducted trials are needed.
Predicting Spontaneous Labor beyond 39 Weeks among Low-Risk Expectantly Managed Pregnant Patients
2022, American Journal of Perinatology

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Predictors of Induction Success

Am J Obstet Gynecol

Obstet Gynecol

Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Lancet

Am J Obstet Gynecol

Bishop score and risk of cesarean delivery after induction of labor in nulliparous women

Obstet Gynecol

The impact of duration of labor induction on cesarean rate

Am J Obstet Gynecol

Maternal risk factors for post-term pregnancy and cesarean delivery following labor induction

Acta Obstet Gynecol