Vaginal birth after caesarean section (VBAC) in women with spontaneous labour: predictors of success

Factors associated with successful vaginal birth after one lower uterine transverse cesarean section delivery

A Trial of labor after cesarean section is an attempt to deliver vaginally by a woman who had a previous cesarean delivery and when achieved by a vaginal delivery it is called successful vaginal birth after cesarean section. Vaginal birth after a caesarian section is a preferred method to decrease complications associated with repeated caesarian section delivery for both mother and fetus. It has a higher success rate when the right women are selected for a trial of labor. This study aimed to assess factors associated with successful vaginal birth after one lower uterine transverse cesarean section and to validate the Flamm and Geiger score at the public hospitals of Bahir Dar City, Northwest, Ethiopia, 2021. A health facility-based retrospective cross-sectional study was conducted from March 1 to 15/2021. A medical record review of 408 women charts with a trial of labor after one lower uterine transverse cesarean section from January 1/2020 to December 31/2020 was done and 345 women charts with complete maternal and fetal information were included in the study with a response rate of 84.6%. The data were collected using a structured checklist, entered into Epi data 3.1, and analyzed using SPSS 25.0 version. Logistic regression analyses were done to estimate the crude and adjusted odds ratio with a confidence interval of 95% and a P-value of less than 0.05 considered statistically significant. This study identified that the trial of labor after cesarean section rate was 69.5%, and the success rate of vaginal birth after one lower uterine transverse cesarean section was 35.07%. Of the failed trial of labor, fetal distress (38.9%) and failed progress of labor (32.1%) were the main indications for an emergency cesarean section. The maternal age group of 21-30 years, prior vaginal birth after or before cesarean section, non-recurring indication (fetal distress and malpresentation), ruptured membrane, cervical dilatation ≥ 4 cm, cervical effacement ≥ 50%, and low station (≥ 0) at admission were associated with successful vaginal birth after one lower uterine transverse cesarean section. For the Flamm and Geiger score at a cut point of 5, the sensitivity and specificity were 73.6% and 86.6% respectively. In this study area, the trial of labor after cesarean section rate is encouraging, however, the success rate of vaginal birth after one lower uterine transverse caesarian section was lower. The maternal socio-demographic and obstetric-related factors were significantly associated with successful vaginal birth after one lower transverse caesarian section delivery. This study indicated that when the Flamm and Geiger score increases, the chance of successful vaginal birth after one lower uterine transverse caesarian section also increases. We suggest emphasizing counselling and encouraging the women, as their chance of successful vaginal delivery will be high in the subsequent pregnancy, especially if the indications of primary caesarian section delivery were non-recurring.

Factors associated with successful vaginal birth after a cesarean section: a systematic review and meta-analysis

Background

Evidence for the relationship between maternal and perinatal factors and the success of vaginal birth after cesarean section (VBAC) is conflicting. We aimed to systematically analyze published data on maternal and fetal factors for successful VBAC.

Methods

A comprehensive search of Medline, Embase, and the Cumulative Index to Nursing and Allied Health Literature, from each database’s inception to March 16, 2018. Observational studies, identifying women with a trial of labor after one previous low-transverse cesarean section were included. Two reviewers independently abstracted the data. Meta-analysis was performed using the random-effects model. Risk of bias was assessed by the Newcastle-Ottawa Scale.

Results

We included 94 eligible observational studies (239,006 pregnant women with 163,502 VBAC). Factors were associated with successful VBAC with the following odds ratios (OR;95%CI): age (0.92;0.86–0.98), obesity (0.50;0.39–0.64), diabetes (0.50;0.42–0.60), hypertensive disorders complicating pregnancy (HDCP) (0.54;0.44–0.67), Bishop score (3.77;2.17–6.53), labor induction (0.58;0.50–0.67), macrosomia (0.56;0.50–0.64), white race (1.39;1.26–1.54), previous vaginal birth before cesarean section (3.14;2.62–3.77), previous VBAC (4.71;4.33–5.12), the indications for the previous cesarean section (cephalopelvic disproportion (0.54;0.36–0.80), dystocia or failure to progress (0.54;0.41–0.70), failed induction (0.56;0.37–0.85), and fetal malpresentation (1.66;1.38–2.01)). Adjusted ORs were similar.

Conclusions

Diabetes, HDCP, Bishop score, labor induction, macrosomia, age, obesity, previous vaginal birth, and the indications for the previous CS should be considered as the factors affecting the success of VBAC.

Success of trial of labor in women with a history of previous cesarean section for failed labor induction or labor dystocia: a retrospective cohort study

Background

The rates of cesarean section (CS) are increasing worldwide leading to an increased risk for maternal and neonatal complications in the subsequent pregnancy and labor. Previous studies have demonstrated that successful trial of labor after cesarean (TOLAC) is associated with the least maternal morbidity, but the risks of unsuccessful TOLAC exceed the risks of scheduled repeat CS. However, prediction of successful TOLAC is difficult, and only limited data on TOLAC in women with previous failed labor induction or labor dystocia exists. Our aim was to evaluate the success of TOLAC in women with a history of failed labor induction or labor dystocia, to compare the delivery outcomes according to stage of labor at time of previous CS, and to assess the risk factors for recurrent failed labor induction or labor dystocia.

Methods

This retrospective cohort study of 660 women with a prior CS for failed labor induction or labor dystocia undergoing TOLAC was carried out in Helsinki University Hospital, Finland, between 2013 and 2015. Data on the study population was obtained from the hospital database and analyzed using SPSS.

Results

The rate of vaginal delivery was 72.9% and the rate of repeat CS for failed induction or labor dystocia was 17.7%. The rate of successful TOLAC was 75.6% in women with a history of labor arrest in the first stage of labor, 73.1% in women with a history of labor arrest in the second stage of labor, and 59.0% in women with previous failed induction. The adjusted risk factors for recurrent failed induction or labor dystocia were maternal height < 160 cm (OR 1.9 95% CI 1.1–3.1), no prior vaginal delivery (OR 8.3 95% CI 3.5–19.8), type 1 or gestational diabetes (OR 1.8 95% CI 1.0–3.0), IOL for suspected non-diabetic fetal macrosomia (OR 10.8 95% CI 2.1–55.9) and birthweight ≥4500 g (OR 3.3 95% CI 1.3–7.9).

Conclusions

TOLAC is a feasible option to scheduled repeat CS in women with a history of failed induction or labor dystocia. However, women with no previous vaginal delivery, maternal height < 160 cm, diabetes or suspected neonatal macrosomia (≥4500 g) may be at increased risk for failed TOLAC.

Labor after cesarean delivery managed without induction or augmentation of labor

BACKGROUND

This study aimed to describe the perinatal outcomes of women opting for vaginal birth after cesarean delivery (VBAC) managed without induction or augmentation of labor.

METHODS

This was a retrospective cohort study of candidates for VBAC at a tertiary center in Japan from April 2003 to March 2012. Women with singleton gestations and one prior low-transverse cesarean delivery who intended VBAC at 36 weeks of gestation were identified as candidates for VBAC and included in the study. Participants were managed without induction or augmentation of labor. Maternal characteristics and perinatal outcomes were obtained from medical records. Factors associated with successful VBAC were analyzed with a multivariable logistic regression model.

RESULTS

Of 333 candidates for VBAC, 242 (72.7%) had vaginal birth, 49 (14.7%) had repeat cesarean delivery with spontaneous labor, and 42 (12.6%) had repeat cesarean delivery without spontaneous labor. The rate of uterine rupture was 0.3% (1/333). Prior vaginal delivery and nonrecurring indications for prior cesarean delivery were associated with successful VBAC.

CONCLUSIONS

Management of candidates for VBAC without induction or augmentation of labor resulted in a high VBAC rate and favorable perinatal outcomes. Such restrictive VBAC policies may be an acceptable alternative to standard management or abandonment of VBAC.

Validation of the close-to-delivery prediction model for vaginal birth after cesarean delivery in a Middle Eastern cohort

OBJECTIVE

To validate a prediction model for vaginal birth after cesarean (VBAC) that incorporates variables available at admission for delivery among Middle Eastern women.

METHODS

The present prospective cohort study enrolled women at 37weeks of pregnancy or more with cephalic presentation who were willing to attempt a trial of labor (TOL) after a single prior low transverse cesarean delivery at Al-Jahra Hospital, Kuwait, between June 2013 and June 2014. The predicted success rate of VBAC determined via the close-to-delivery prediction model of Grobman et al. was compared between participants whose TOL was and was not successful.

RESULTS

Among 203 enrolled women, 140 (69.0%) had successful VBAC. The predicted VBAC success rate was higher among women with successful TOL (82.4%±13.1%) than among those with failed TOL (67.7%±18.3%; P<0.001). There was a high positive correlation between actual and predicted success rates. For deciles of predicted success rate increasing from >30%-40% to >90%-100%, the actual success rate was 20%, 30.7%, 38.5%, 59.1%, 71.4%, 76%, and 84.5%, respectively (r=0.98, P=0.013).

CONCLUSION

The close-to-delivery prediction model was found to be applicable to Middle Eastern women and might predict VBAC success rates, thereby decreasing morbidities associated with failed TOL.