Induction of labor after a prior cesarean delivery: lessons from a population-based study

Delivery mode after cervical ripening among patients with no prior vaginal births

PURPOSE

To compare mode of delivery and maternal and neonatal outcomes using cervical ripening balloon (CRB) for induction of labor (IOL) in nulliparous patients vs. those undergoing first trial of labor after cesarean (TOLAC).

METHODS

Retrospective cohort study including data from two tertiary medical centers. Included were all patients with a singleton pregnancy and a gestational age > 37+0 weeks and no prior vaginal birth undergoing IOL with CRB. Nulliparous patients (nulliparous group) were compared to patients with one prior cesarean delivery (CD) and no prior vaginal delivery (TOLAC group). Patients who withdrew consent for trial of labor at any time in both groups were excluded. The primary outcome was mode of delivery.

RESULTS

Overall, 161 patients were included in the TOLAC group and 1577 in the nulliparous group. The rate of CD was similar in both groups and remained similar after adjusting for confounders (29.8 % vs. 28.9 %, p = 0.86, OR 1.1, 95 %, CI 0.76-1.58). CD due to fetal distress was more common in the TOLAC group (75 % vs. 56 %, p = 0.014). Other maternal outcomes and neonatal outcomes were similar in the two groups.

CONCLUSION

Comparable vaginal delivery rates may be achieved in patients with or without a previous CD attempting their first trial of labor, with a cervical ripening balloon for labor induction, without increasing adverse maternal or neonatal outcomes.

Validation of Grobman’s graphical nomogram for prediction of vaginal delivery in Indian women with previous caesarean section

Purpose

To validate Grobman's nomogram for prediction of trial of labour after caesarean section (TOLAC) success in the Indian population.

Methods

A prospective observational study of women with previous lower segment caesarean sections (LSCS) who were admitted for TOLAC between January 2019 and June 2020 at a tertiary care hospital We compared the Grobman's predicted VBAC success probability to the observed VBAC rate in the study population and devised a receiver-operator characteristics (ROC) curve for the nomogram.

Results

Among the 124 women with prior LSCS who chose TOLAC and were included in the study, 68 (54.8%) had a successful VBAC and 56 (45.2%) had a failed TOLAC. The mean Grobman's predicted success probability for the cohort was 76.7%, significantly higher in VBAC women versus CS women (80.6% vs. 72.1%; p 0.001). The VBAC rate was 69.1% with a predicted probability of > 75% and only 42.9% with a probability of 50%. Women in the > 75% probability group had a nearly similar observed and predicted VBAC rate (69.1% vs. 86.3%; p = 0.002), and a greater number of women in the 50% probability group had successful VBAC than predicted (42.9% vs. 39.5%; p = 0.018). The area under the ROC curve for the study was 0.703 (95% CI 0.609-0.797; p 0.001). Grobman's nomogram had a sensitivity of 57.35%, a specificity of 82.14%, a positive predictive value (PPV) of 79.59%, and a negative predictive value (NPV) of 61.33% at a predicted probability cut-off of 82.5%.

Conclusions

Women who had a higher Grobman's predicted probability had greater VBAC success rates than those with low predicted probability scores. The prediction ability of the nomogram was highly accurate at higher predicted probabilities, and even at lower predicted probabilities, women did have good odds of delivering vaginally.

Planned mode of birth after previous cesarean section: A structured review of the evidence on the associated outcomes for women and their children in high-income setting

In many high-income settings policy consensus supports giving pregnant women who have had a previous cesarean section a choice between planning an elective repeat cesarean section (ERCS) or planning a vaginal birth after previous cesarean (VBAC), provided they have no contraindications to VBAC. To help women make an informed decision regarding this choice, clinical guidelines advise women should be counseled on the associated risks and benefits. The most recent and comprehensive review of the associated risks and benefits of planned VBAC compared to ERCS in high-income settings was published in 2010 by the US Agency for Healthcare Research and Quality (AHRQ). This paper describes a structured review of the evidence in high-income settings that has been published since the AHRQ review and the literature in high-income settings that has been published since 1980 on outcomes not included in the AHRQ review. Three databases (MEDLINE, EMBASE, and PsycINFO) were searched for relevant studies meeting pre-specified eligible criteria, supplemented by searching of reference lists. Forty-seven studies were identified as meeting the eligibility criteria and included in the structured review. The review suggests that while planned VBAC compared to ERCS is associated with an increased risk of various serious birth-related complications for both the mother and her baby, the absolute risk of these complications is small for either birth approach. The review also found some evidence that planned VBAC compared to ERCS is associated with benefits such as a shorter length of hospital stay and a higher likelihood of breastfeeding. The limited evidence available also suggests that planned mode of birth after previous cesarean section is not associated with the child’s subsequent risk of experiencing adverse neurodevelopmental or health problems in childhood. This information can be used to manage and counsel women with previous cesarean section about their subsequent birth choices. Collectively, the evidence supports existing consensus that there are risks and benefits associated with both planned VBAC and ERCS, and therefore women without contraindications to VBAC should be given an informed choice about planned mode of birth after previous cesarean section. However, further studies into the longer-term effects of planned mode of birth after previous cesarean section are needed along with more research to address the other key limitations and gaps that have been highlighted with the existing evidence.

Clinical interventions that influence vaginal birth after cesarean delivery rates: Systematic Review & Meta-Analysis

Background

To systematically review the literature on clinical interventions that influence vaginal birth after cesarean (VBAC) rates.

Methods

We searched Ovid Medline, Ovid Embase, Wiley Cochrane Library, CINAHL via EBSCOhost; and Ovid PsycINFO. Additional studies were identified by searching for clinical trial records, conference proceedings and dissertations. Limits were applied for language (English and French) and year of publication (1985 to present). Two reviewers independently screened comparative studies (randomized or non-randomized controlled trials, and observational designs) according to a priori eligibility criteria: women with prior cesarean sections; any clinical intervention or exposure intended to increase the VBAC rate; any comparator; and, outcomes reporting VBAC, uterine rupture and uterine dehiscence rates. One reviewer extracted data and a second reviewer verified for accuracy. Meta-analysis was conducted using Mantel-Haenszel (random effects model) relative risks (VBAC rate) and risk differences (uterine rupture and dehiscence). Two reviewers independently conducted methodological quality assessments using the Mixed Methods Appraisal Tool (MMAT).

Results

Twenty-nine studies (six trials and 23 cohorts) examined different clinical interventions affecting rates of vaginal deliveries among women with a prior cesarean delivery (CD). Methodological quality was good overall for the trials; however, concerns among the cohort studies regarding selection bias, comparability of groups and outcome measurement resulted in higher risk of bias. Interventions for labor induction, with or without cervical ripening, included pharmacologic (oxytocin, prostaglandins, misoprostol, mifepristone, epidural analgesia), non-pharmacologic (membrane sweep, amniotomy, balloon devices), and combined (pharmacologic and non-pharmacologic). Single studies with small sample sizes and event rates contributed to most comparisons, with no clear differences between groups on rates of VBAC, uterine rupture and uterine dehiscence.

Conclusions

This systematic review evaluated clinical interventions directed at increasing the rate of vaginal delivery among women with a prior CD and found low to very low certainty in the body of evidence for cervical ripening and/or labor induction techniques. There is insufficient high-quality evidence to inform optimal clinical interventions among women attempting a trial of labor after a prior CD.

Planned mode of delivery after previous cesarean section and short-term maternal and perinatal outcomes: A population-based record linkage cohort study in Scotland

BACKGROUND

Policy consensus in high-income countries supports offering pregnant women with previous cesarean section a choice between planning an elective repeat cesarean section (ERCS) or attempting a vaginal birth, known as a planned vaginal birth after previous cesarean (VBAC), provided they do not have contraindications to planned VBAC. However, robust comprehensive information on the associated outcomes to counsel eligible women about this choice is lacking. This study investigated the short-term maternal and perinatal outcomes associated with planned mode of delivery after previous cesarean section among women delivering a term singleton and considered eligible to have a planned VBAC.

METHODS AND FINDINGS

A population-based cohort of 74,043 term singleton births in Scotland between 2002 and 2015 to women with one or more previous cesarean sections was conducted using linked Scottish national datasets. Logistic or modified Poisson regression, as appropriate, was used to estimate the effect of planned mode of delivery on maternal and perinatal outcomes adjusted for sociodemographic, maternal medical, and obstetric-related characteristics. A total of 45,579 women gave birth by ERCS, and 28,464 had a planned VBAC, 28.4% of whom went on to have an in-labor nonelective repeat cesarean section. Compared to women delivering by ERCS, those who had a planned VBAC were significantly more likely to have uterine rupture (0.24%, n = 69 versus 0.04%, n = 17, adjusted odds ratio [aOR] 7.3, 95% confidence interval [CI] 3.9-13.9, p < 0.001), a blood transfusion (1.14%, n = 324 versus 0.50%, n = 226, aOR 2.3, 95% CI 1.9-2.8, p < 0.001), puerperal sepsis (0.27%, n = 76 versus 0.17%, n = 78, aOR 1.8, 95% CI 1.3-2.7, p = 0.002), and surgical injury (0.17% versus 0.09%, n = 40, aOR 3.0, 95% CI 1.8-4.8, p < 0.001) and experience adverse perinatal outcomes including perinatal death, admission to a neonatal unit, resuscitation requiring drugs and/or intubation, and an Apgar score < 7 at 5 minutes (7.99%, n = 2,049 versus 6.37%, n = 2,570, aOR 1.6, 95% CI 1.5-1.7, p < 0.001). However, women who had a planned VBAC were more likely than those delivering by ERCS to breastfeed at birth or hospital discharge (63.6%, n = 14,906 versus 54.5%, n = 21,403, adjusted risk ratio [aRR] 1.2, 95% CI 1.1-1.2, p < 0.001) and were more likely to breastfeed at 6-8 weeks postpartum (43.6%, n = 10,496 versus 34.5%, n = 13,556, aRR 1.2, 95% CI 1.2-1.3, p < 0.001). The effect of planned mode of delivery on the mother's risk of having a postnatal stay greater than 5 days, an overnight readmission to hospital within 42 days of birth, and other puerperal infection varied according to whether she had any prior vaginal deliveries and, in the case of length of postnatal stay, also varied according to the number of prior cesarean sections. The study is mainly limited by the potential for residual confounding and misclassification bias.

CONCLUSIONS

Among women considered eligible to have a planned VBAC, planned VBAC compared to ERCS is associated with an increased risk of the mother having serious birth-related maternal and perinatal complications. Conversely, planned VBAC is associated with an increased likelihood of breastfeeding, whereas the effect on other maternal outcomes differs according to whether a woman has any prior vaginal deliveries and the number of prior cesarean sections she has had. However, the absolute risk of adverse outcomes is small for either delivery approach. This information can be used to counsel and manage the increasing number of women with previous cesarean section, but more research is needed on longer-term outcomes.

[Risk of uterine rupture in vaginal birth after cesarean: Systematic review]

OBJECTIVE

To assess the risk of uterine rupture (UR) in attempted vaginal birth after cesarean and to identify risk factors.

METHODS

Systematic review by consulting the following databases: PubMed (MEDLINE), Cochrane Library Plus, Embase, Nursing@Ovid, Cuidatge and Dialnet. The search was conducted between January and March 2015. MeSH descriptors used were: vaginal birth after cesarean; uterine rupture; labor induced and labor obstetric or trial of labor. There were no restrictions on date or language. The selection of articles was performed by 2 independent reviewers, standardized and unblinded. A critical review of the summary was conducted, and if was necessary, the full text was consulted. Prospective and retrospective documents were included.

RESULTS

A total of 39 documents were included for their relevance and interest. Few clinical trials were found. The UR incidence on the results of the studies analyzed ranged from 0.15-0.98% in spontaneous labor; 0.3-1.5% in stimulation and induction with oxytocin, and 0.68-2.3% in prostaglandin inductions.

CONCLUSIONS

The success of vaginal birth after cesarean is important and improves when conditions are optimal. However it is not without risks, the main one being UR. Induction of labor with oxytocin and/or prostaglandins appears as the main risk factor, while the spontaneous onset of labor and a prior vaginal birth are protective factors.