Trial of labor after cesarean, vaginal birth after cesarean, and the risk of uterine rupture: an expert review.

The decision to pursue a trial of labor after cesarean delivery is complex and depends on patient preference, the likelihood of successful vaginal birth after cesarean delivery, assessment of the risks vs benefits of trial of labor after cesarean delivery, and available resources to support safe trial of labor after cesarean delivery at the planned birthing center. The most feared complication of trial of labor after cesarean delivery is uterine rupture, which can have catastrophic consequences, including substantial maternal and perinatal morbidity and mortality. Although the absolute risk of uterine rupture is low, several clinical, historical, obstetrical, and intrapartum factors have been associated with increased risk. It is therefore critical for clinicians managing patients during trial of labor after cesarean delivery to be aware of these risk factors to appropriately select candidates for trial of labor after cesarean delivery and maximize the safety and benefits while minimizing the risks. Caution is advised when considering labor augmentation and induction in patients with a previous cesarean delivery. With established hospital safety protocols that dictate close maternal and fetal monitoring, avoidance of prostaglandins, and careful titration of oxytocin infusion when induction agents are needed, spontaneous and induced trial of labor after cesarean delivery are safe and should be offered to most patients with 1 previous low transverse, low vertical, or unknown uterine incision after appropriate evaluation, counseling, planning, and shared decision-making. Future research should focus on clarifying true risk factors and identifying the optimal approach to intrapartum and induction management, tools for antenatal prediction, and strategies for prevention of uterine rupture during trial of labor after cesarean delivery. A better understanding will facilitate patient counseling, support efforts to improve trial of labor after cesarean delivery and vaginal birth after cesarean delivery rates, and reduce the morbidity and mortality associated with uterine rupture during trial of labor after cesarean delivery.

Risk of stillbirth after a previous caesarean delivery: A Swedish nationwide cohort study.

OBJECTIVES: To investigate the risk of stillbirth in relation to (1) a previous caesarean delivery (CD) compared with those following a vaginal birth (VB); and (2) vaginal birth after caesarean (VBAC) compared with a repeat CD. DESIGN: Population-based cohort study. SETTING: The Swedish Medical Birth registry. POPULATION: Women with their first and second singletons between 1982 and 2012. METHODS: Multivariable logistic regression models were performed to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) of the association between CD in the first pregnancy and stillbirth in the second pregnancy and the association between VBAC and stillbirth. Sub-group analyses were performed by types of CD and timing of stillbirth (antepartum and intrapartum). MAIN OUTCOME MEASURES: Stillbirth (antepartum and intrapartum fetal death). RESULTS: Of the 1 771 700 singleton births from 885 850 women, 117 114 (13.2%) women had a CD in the first pregnancy, and 51 755 had VBAC in the second pregnancy. We found a 37% increased odds of stillbirth (aOR 1.37; 95% CI 1.23-1.52) in women with a previous CD compared with VB. The odds of intrapartum stillbirth were higher in the previous pre-labour CD group (aOR 2.72; 95% CI 1.51-4.91) and in the previous in-labour CD group (aOR 1.35; 95% CI 0.76-2.40), although not statistically significant in the latter case. No increased odds were found for intrapartum stillbirth in women who had VBAC (aOR 0.99; 95% CI 0.48-2.06) compared with women who had a repeat CD. CONCLUSIONS: This study confirms that a CD is associated with an increased risk of subsequent stillbirth, with a greater risk among pre-labour CD. This association is not solely mediated by increases in intrapartum asphyxia, uterine rupture or attempted VBAC. Further research is needed to understand this association, but these findings might help healthcare providers to reach optimal decisions regarding mode of birth, particularly when CD is unnecessary.

Examining provider practice-level disparities in delivery outcomes among patients with a history of Cesarean Delivery.

BACKGROUND: Choosing whether to pursue a trial of labor after cesarean (TOLAC) or scheduled repeat cesarean delivery (SRCD) requires prenatal assessment of risks and benefits. Providers and patients play a central role in this process. However, the influence of provider-associated characteristics on delivery methods remains unclear. We hypothesized that different provider practice groups have different obstetric outcomes in patients with one prior cesarean delivery (CD). METHODS: This was a retrospective cohort study of deliveries between April 29, 2015 - April 29, 2020. Subjects were divided into three cohorts: SRCD, successful VBAC, and unsuccessful VBAC (patients who chose TOLAC but had a CD). Disparities were reviewed between five different obstetric provider practice groups, determined from a breakdown of different providers delivering at the study site during the study period. Proportional differences were examined using Chi-squared tests and logistic regression models. RESULTS: 1,439 deliveries were included in the study. There were significant proportional disparities between patients in the different groups. Specifically, patients from Group D were significantly more likely to undergo successful VBAC, while patients seeing a provider from Group A were more likely to deliver by SRCD. In our multivariate analysis of successful versus unsuccessful VBAC, patients from Group D had greater odds ratios of successful VBAC compared to Group A. Patients delivered by Group E had a significantly lower odds ratio of successful VBAC. CONCLUSION: This study suggests an association between provider practice groups and delivery outcomes among patients with one prior CD. These data contribute to a growing body of literature around patient choice in pregnancy and the interplay of patients and providers. These findings help to guide future investigations to improve outcomes among patients with a history of CD.

Trial of labour after two caesarean sections (TOLA2C) and risk of uterine rupture, a retrospective single centre study.

BACKGROUND: Most German hospitals do not offer a trial of labour after two caesarean sections (TOLA2C). TOLA2C is claimed to be associated with too many complications, above all the high risk of uterine rupture. The objective of this study is to review our experience with TOLA2C, with special attention paid to the risk and probability of uterine ruptures. Secondary outcomes include comparing neonatal and maternal outcomes in the group of TOLA2C with the group of elective repeat caesarean section (ERCS) and to assess the success rate for vaginal birth after two caesarean sections (VBAC-2). METHODS: The retrospective cohort study was conducted in a community hospital in North Rhine-Westphalia. Inclusion criteria were all pregnant women with two caesarean sections in their medical history, with a current vertex singleton pregnancy and the absence of morphological abnormalities of the foetus, who gave birth in our facility between January 2015 and June 2021. Descriptive statistics were calculated and Kolmogorov-Smirnov tests, Mann-Whitney U tests, Fishers exact tests, Chi2 -tests and t-tests for independent samples were performed. RESULTS: A total of 91 cases were included in the TOLA2C-group. These were compared to 99 cases that, within the same time frame, had an elective repeat caesarean section (ERCS-group). There was no statistically significant difference found in the neonatal outcome between the two groups (except for the neonatal pH-value: p 0.024). The hospital stay was significantly shorter in the TOLA2C-group, while maternal complication rates were almost similar (13.2% in the TOLA2C-Group, vs. 16.2% in the ERCS-Group). The success rate for TOLA2C was 55%. No complete uterine rupture was found, but in three cases an incomplete rupture (3.3% rate for incomplete uterine ruptures) occurred, but had no influence on the neonatal outcome. CONCLUSION: TOLA2C is not associated with a worse maternal or neonatal outcome compared to ERCS, and especially the risk of complete uterine ruptures seems to be low. TOLA2C should be more widely offered to suitable patients who are motivated for it.

Short stature and vaginal dinoprostone as independent predictors of composite maternal-newborn adverse outcomes in induction of labor after one previous cesarean: a retrospective cohort study.

BACKGROUND: The rates of labor induction and cesarean delivery is rising worldwide. With the confluence of these trends, the labor induction rate in trials of labor after cesarean can be as high as 27-32.7%. Induction of labor after one previous cesarean (IOLAC) is a high-risk procedure mainly due to the higher risk of uterine rupture. Nevertheless, the American College of Obstetricians and Gynecologists considers IOLAC as an option in motivated and informed women in the appropriate care setting. We sought to identify predictors of a composite of maternal and newborn adverse outcomes following IOLAC. METHODS: The electronic medical records of women who delivered between January 2018 to September 2022 in a Malaysian university hospital were screened to identify cases of IOLAC. A case is classified as a composite adverse outcome if at least one of these 11 adverse outcomes of delivery blood loss ≥ 1000 ml, uterine scar complications, cord prolapse or presentation, placenta abruption, maternal fever (≥ 38 0C), chorioamnionitis, intensive care unit (ICU) admission, Apgar score < 7 at 5 min, umbilical artery cord artery blood pH < 7.1 or base excess ≤-12 mmol/l, and neonatal ICU admission was present. An unplanned cesarean delivery was not considered an adverse outcome as the practical management alternative for a clinically indicated IOLAC was a planned cesarean. Bivariate analysis of participants' characteristics was performed to identify predictors of their association with composite adverse outcome. Characteristics with crude p < 0.10 on bivariate analysis were incorporated into a multivariable binary logistic regression analysis model. RESULTS: Electronic medical records of 19,064 women were screened. 819 IOLAC cases and 98 cases with composite adverse outcomes were identified. Maternal height, ethnicity, previous vaginal delivery, indication of previous cesarean, indication for IOLAC, and method of IOLAC had p < 0.10 on bivariate analysis and were incorporated into a multivariable binary logistic regression analysis. After adjustment, only maternal height and IOLAC by vaginal dinoprostone compared to Foley balloon remained significant at p < 0.05. Post hoc adjusted analysis that included all unplanned cesarean as an added qualifier for composite adverse outcome showed higher body mass index, short stature (< 157 cm), not of Chinese ethnicity, no prior vaginal delivery, prior cesarean indicated by labor dystocia, and less favorable Bishop score (< 6) were independent predictors of the expanded composite adverse outcome. CONCLUSION: Shorter women and IOLAC by vaginal dinoprostone compared to Foley balloon were independently predictive of composite of adverse outcome.

Shorter stature and dinoprostone labor induction are independent predictors of a composite maternal-newborn adverse outcome excluding unplanned cesarean delivery.

The association between obesity and the success of trial of labor after cesarean delivery (TOLAC) in women with past vaginal delivery.

OBJECTIVES: To evaluate the effect of overweight (body mass index; BMI 25.0-29.9 kg/m2), and obesity (BMI>30 kg/m2), on the success of trial of labor after cesarean delivery (TOLAC), with consideration of successful past vaginal birth. METHODS: This retrospective cohort study was performed using electronic database of obstetrics department at a university-affiliated tertiary medical center. All women admitted for TOLAC at 37-42 weeks of gestational age, carrying a singleton live fetus at cephalic presentation, with a single previous low segment transverse cesarean delivery between 1/2015 and 5/2021 were included. Primary outcome was the rate of cesarean delivery during labor, and subgroup analysis was performed for the presence of past vaginal birth. RESULTS: Of the 1200 TOLAC deliveries meeting the inclusion criteria, 61.9 % had BMI in the normal range, 24.6 % were overweight (BMI 25.0-29.9 kg/m2), and 13.4 % were obese (BMI of 30 kg/m2 and over). Using a multivariate analysis, BMI≥30 kg/m2 was associated with increased risk of cesarean delivery compared to normal weight. However, in the subgroup of 292 women with a history of successful vaginal birth BMI did not affect TOLAC success. CONCLUSIONS: BMI does not affect the success of TOLAC in women with previous vaginal birth. This information should be considered during patients counselling, in order to achieve a better selection of mode of delivery and higher patients' satisfaction.

Second stage duration and delivery outcomes among women laboring after cesarean with no prior vaginal delivery.

BACKGROUND: We aimed to evaluate the association of the duration of the second stage with labor after cesarean (LAC) success and other outcomes among women with one prior cesarean delivery (CD) and no prior vaginal births. METHODS: All women undergoing LAC that reached the second stage of labor from March 2011 to March 2020 were included in this retrospective cohort study. The primary outcome was the mode of delivery by second stage duration. The secondary outcomes included adverse maternal and neonatal outcomes. We allocated the study cohort into five groups of second stage duration. Further analysis compared <3 to ≥3 h of second stage based on prior studies. LAC success rates were compared. Composite maternal outcome was defined as the presence of uterine rupture/dehiscence, postpartum hemorrhage, or intrapartum/postpartum fever. RESULTS: One thousand three hundred ninety seven deliveries were included. Vaginal birth after cesarean (VBAC) rates decreased as the second stage length time interval increased: 96.4% at <1 h, 94.9% at 1 to <2 h, 94.6% at 2 to <3 h, 92.1% at 3 to <4 h and 79.5% at ≥4 h (p < 0.001). Operative vaginal and CDs were significantly more likely as second stage duration time interval increased (p < 0.001). The composite maternal outcome was comparable among groups (p = 0.226). When comparing the outcomes of deliveries at <3 h versus ≥3 h, the composite maternal outcome and neonatal seizure rates were lower in the <3 h group (p = 0.041 and p = 0.047, respectively). CONCLUSION: Vaginal birth after cesarean rates decreased as second stage time interval length increased. Even with prolonged second stage, VBAC rates remained relatively high. Increased risk of composite adverse maternal outcomes and neonatal seizures were observed when the second stage lasted 3 h or more.

Trial of labor following cesarean in preterm deliveries: success rates and maternal and neonatal outcomes: a multicenter retrospective study.

PURPOSE: To evaluate the rates of vaginal birth after cesarean (VBAC) among parturients attempting preterm trial of labor following a cesarean delivery (TOLAC) vs. term TOLAC. METHODS: A multicenter historic cohort study was conducted at two university-affiliated centers between August 2005 and March 2021. Parturients in their second delivery, attempting TOLAC after a single low segment transverse cesarean delivery were included. We retrospectively examined computerized medical records of all preterm (< 37 weeks) and term (37-42 weeks) births. Multifetal gestations and postterm deliveries (≥ 42 weeks) were excluded. A univariate analysis was conducted, followed by a multivariate analysis. RESULTS: 4865 second deliveries following previous cesarean were identified: 212 (4.4%) preterm and 4653 (95.6%) term. Hypertensive disorders, diabetes and fertility treatments were significantly more prevalent in the preterm group. VBAC rate was significantly lower in preterm group (57.5 vs 79.7%., p < 0.01), including both spontaneous and vaginal-assisted deliveries. In multivariate analysis, preterm TOLAC was independently associated with TOLAC failure [adjusted odds ratio 2.24, [95% confidence interval 1.62-3.09]. Overall, maternal outcomes were favorable. Rates of uterine rupture, re-laparotomy and postpartum hemorrhage were comparable between groups. Neonatal outcomes were less favorable among the preterm group; however, preterm vs. term TOLAC was not associated with low 5 min Apgar score (aOR 1.76, 95% CI 0.92-3.40). CONCLUSION: In our study, VBAC rates were lower in preterm compared to term deliveries. Maternal outcomes were comparable. Neonatal outcomes were less favorable in the preterm group, more likely due to prematurity than delivery mode.

Evaluation of the usefulness of ultrasound measurement of the lower uterine segment before delivery of women with a prior cesarean delivery: a randomized trial.

BACKGROUND: The main reason to avoid trial of labor after cesarean delivery is the possibility of uterine rupture. Identifying women at risk is thus an important aim, for it would enable women at low risk to proceed with a secure planned vaginal birth. OBJECTIVE: To evaluate the impact of proposing mode of delivery based on the ultrasound measurement of the lower uterine segment thickness on a composite outcome of maternal-fetal mortality and morbidity, compared with usual management, among pregnant women with a previous cesarean delivery. STUDY DESIGN: This multicenter, randomized, controlled, parallel-group, unmasked trial was conducted at 8 referral university hospitals with a neonatal intensive care unit and enrolled 2948 women at 36 weeks 0 days to 38 weeks 6 days of gestation with 1 previous low transverse cesarean delivery and no contraindication to trial of labor. Women in the study group had their lower uterine segment thickness measured by ultrasound. Those with measurements >3.5 mm, were encouraged to choose a planned vaginal delivery, and those with measurements ≤3.5 mm, were encouraged to choose a planned repeat cesarean delivery. This measurement was not taken in the control group; their mode of delivery was decided according to standard management. The primary outcome was a composite criterion comprising maternal mortality, uterine rupture, uterine dehiscence, hysterectomy, thromboembolic disease, transfusion, endometritis, perinatal death, or neonatal encephalopathy. Prespecified secondary outcomes were repeat cesarean deliveries, elective or after trial of labor. RESULTS: The study group included 1472 women, and the control group included 1476 women. These groups were similar at baseline. The primary outcome occurred in 3.4% of the study group and 4.3% of the control group (relative risk, 0.78; 95% confidence interval, 0.54-1.13: risk difference, -1.0%; 95% confidence interval, -2.4 to 0.5). The uterine rupture rate in the study group was 0.4% and in the control group 0.9% (relative risk, 0.43; 95% confidence interval, 0.15-1.19). The planned cesarean delivery rate was 16.4% in the study group and 13.7% in the control group (relative risk, 1.21; 95% confidence interval, 1.00-1.47), whereas the rates of cesarean delivery during labor were 25.1% and 25.0% (relative risk, 1.01; 95% confidence interval, 0.89-1.14) in the study and control groups, respectively. CONCLUSION: Ultrasound measurements of lower uterine segment thickness did not result in a statistically significant lower frequency of maternal and perinatal adverse outcomes than standard management. However, because this study was underpowered, further research should be encouraged.

Neonatal outcomes in trial of vaginal birth versus repeat caesarean delivery in preterm pregnancies: A prospective cohort study.

OBJECTIVE: To characterise neonatal morbidity following preterm trial of labour (TOL) in comparison with elective repeat caesarean section (eRCS) specifically among patients without a previous vaginal delivery who may have a lower success rate of vaginal birth after caesarean. DESIGN: This is a secondary analysis of a multicentre prospective database. SETTING/POPULATION: Maternal and Fetal Medicine Unit Cesarean Section Registry. POPULATION: Singleton pregnancies in women without a previous vaginal delivery who delivered at 24+0  weeks to 36+6  weeks gestation. METHODS: Neonatal outcomes were compared between those with a TOL and those undergoing eRCS. Logistic regression was used to control for confounders, including gestational age at delivery. MAIN OUTCOME MEASURES: Composite neonatal morbidity. RESULTS: A total of 1906 patients were included, 985 with TOL and 921 with no TOL. The TOL success rate was 63.1%. The rate of uterine rupture was low, at 0.10% in the TOL group and 0.11% in the eRCS group (p = 0.32). After adjustment, neonates born to women undergoing a TOL had no statistically significant difference in outcomes including composite neonatal outcome (adjusted odds ratio 0.86, 95% CI 0.68-1.09), neonatal intensive care unit admission, respiratory distress syndrome, necrotising enterocolitis, hypoxic ischaemic encephalopathy, seizures, transient tachypnoea of the newborn, compared with patients who underwent eRCS, with the exception of decreased risk of proven/suspected sepsis (adjusted odds ratio 0.68, 95% CI 0.52-0.87) CONCLUSION: A TOL in preterm patients without a previous vaginal delivery was not found to have a statistically significant association with increased neonatal morbidity.

How does uterine contractile activity affect the success of trial of labour after caesarean section, and the risk of uterine rupture? An exploratory, blinded analysis of a cohort from a randomised controlled trial.

OBJECTIVE: To investigate the impact of uterine contractile activity on the outcome of trial of labour after caesarean section (TOLAC). DESIGN: Secondary, blinded analyses of a prospective TOLAC cohort. SETTING: Two labour wards, one in a university tertiary hospital and the other in a central hospital. POPULATION: A total of 194 TOLAC parturients with intrauterine tocodynamometry during labour. METHODS: Analysis of intrauterine pressure, frequency of contractions and baseline tonus of uterine muscle in 30-minute periods for 4 hours before birth. MAIN OUTCOME MEASURES: Primary outcome: uterine contractile activity during TOLAC. Secondary aims: contributors associated with failed TOLAC and uterine rupture. RESULTS: TOLAC succeeded in 74% of cases. Uterine contractile activity, expressed as intrauterine pressure, was significantly higher in successful TOLAC compared with failed TOLAC (210 versus 170 Montevideo units). The statistically significant risk factors of failed TOLAC, after multivariate regression analysis, were prolonged gestational age, reduced cervical dilatation at admission and lower mean intrauterine pressure. In cases of uterine rupture, contractile activity did not differ from that in failed TOLAC. Cervical ripening with a Foley catheter appeared to be a risk factor for uterine rupture, as well as cervical dilatation <3 cm at admission. The incidence of total uterine rupture was 2.6% (n = 5). CONCLUSIONS: Women with successful vaginal birth had higher uterine contractile activity than those experiencing failed TOLAC or uterine rupture despite similar use of oxytocin. Induction of labour with a Foley catheter turned out to be a risk factor for uterine rupture during TOLAC among parturients with no previous vaginal delivery. TWEETABLE ABSTRACT: During VBAC the response to oxytocin, assessed as intrauterine pressure, is greater and adequate, in contrast to failed TOLAC.

Outcomes and risk factors for failed trial of labor after cesarean delivery (TOLAC) in women with one previous cesarean section: a Chinese population-based study.

OBJECTIVE: To evaluate the outcomes and risk factors for trial of labor after cesarean delivery (TOLAC) failure in patients in China. METHODS: Consecutive patients who had a previous cesarean delivery (CD) and attempted TOLAC were included from 2014 to 2020. Patients who successfully delivered were classified into the TOLAC success group. Patients who attempted TOLAC but had a repeat CD due to medical issues were classified into the TOLAC failure group. Multiple logistic regression analyses were performed to examine the risk factors for TOLAC failure. RESULTS: In total, 720 women who had a previous CD and attempted TOLAC were identified and included. The success rate of TOLAC was 84.2%(606/720). Seven patients were diagnosed with uterine rupture, none of whom underwent hysterectomy. Multiple logistic regression analysis showed that the induction of labor (OR = 2.843, 95% CI: 1.571-5.145, P < 0.001) was positively associated with TOLAC failure, but the thickness of the lower uterine segment (LUS) (OR = 0.215, 95% CI: 0.103-0.448, P < 0.001) was negatively associated with TOLAC failure. CONCLUSIONS: This study suggested that TOLAC was effective in decreasing CD rates in the Chinese population. The induction of labor was positively associated with TOLAC failure, but the thickness of the LUS was negatively associated with TOLAC failure. Our findings need to be confirmed in larger samples with patients of different ethnicities.

A predictive nomogram for a failed trial of labor after cesarean: A retrospective cohort study.

AIM: To validate risk factors and a nomogram prediction model for the failure of a trial of labor after cesarean section (TOLAC) in a Chinese population. METHODS: We included women who tried TOLAC between January 2017 and May 2019, grouped according to the success/failure of TOLAC. The patients were randomized 3:1 into the development and validation sets. Multivariable logistic regression analyses were used to develop a nomogram prediction model for TOLAC failure. RESULTS: In total, 535 (86.3%) of the women (n = 620) aged 29-34 years had a successful vaginal birth after cesarean (VBAC). All women had a fully healed previous uterine incision. The univariable analyses showed that the cephalopelvic score (p < 0.001), BMI (p = 0.001), full engagement into the pelvis (p < 0.001), Bishop cervical maturity score (p < 0.001), and estimated fetal weight at admission (p < 0.001) could enter the multivariable model. Furthermore, the multivariable analysis showed that the cephalopelvic score (OR = 0.42, 95%CI: 0.23-0.77, p = 0.005), full engagement in the pelvis (OR = 0.16, 95%CI: 0.08-0.33, p < 0.001), and Bishop cervical maturity score (OR = 0.46, 95%CI: 0.35-0.59, p < 0.001) were independent predictors of the failure of TOLAC. CONCLUSION: This study proposes a nomogram that can assess the risk of failure of TOLAC in Chinese pregnant women. The statistical model could help clinicians know the likelihood of successful TOLAC in the clinical setting.

Is there an Association between Vaginal Birth after Cesarean Prediction and Obstetric Anal Sphincter Injury?

OBJECTIVE: This study aimed to estimate whether there is an association between the predicted probability of vaginal birth after cesarean delivery (VBAC) and the occurrence of obstetric anal sphincter injuries (OASIS). STUDY DESIGN: This was a single-site retrospective cohort study of all women with a singleton vaginal birth after a previous cesarean section between January 2011 and December 2016. Women were divided into four ordinal groupings by the predicted probability of achieving vaginal birth after cesarean using the Maternal-Fetal Medicine Units Network VBAC calculator (less than 41%, 40.1-60%, 60.1-80%, and greater than 80%). The primary outcome was OASIS, defined as a 3rd or 4th degree perineal laceration. Bivariable and multivariable analyses were used to examine the association between predicted VBAC probability and OASIS. RESULTS: In total, 1,411 women met inclusion criteria and 73 (5.2%) sustained OASIS. The median predicted probability of VBAC was lower in women with OASIS compared with those without OASIS (60% [interquartile range {IQR}: 48-70%] vs. 66% (IQR: 52-80%), p = 0.02]. On bivariable and multivariable logistic regression, predicted probability of VBAC was associated with increased odds of OASIS (less than 41% probability: adjusted odds ratio [aOR]: 3.18, 95% confidence interval [CI]: 0.90-11.21; 41-60% probability: aOR: 3.76, 95% CI: 1.34-10.57; 61-80% probability aOR: 3.47, 95% CI: 1.25-9.69) relative to women with a predicted probability of VBAC of greater than 80%. CONCLUSION: Having a lower predicted probability of VBAC is associated with an increased risk of OASIS at the time of a VBAC relative to those with greater than 80% predicted probability. Incorporation of this aspect of maternal morbidity may inform risk-stratification at the time of trial of labor after cesarean, as well as the choice of performing an operative vaginal delivery. KEY POINTS: · Predicted probability of VBAC is associated with OASIS.. · Low predicted probability of VBAC is associated with increased odds of OASIS.. · Forceps delivery was associated with the highest odds of OASIS..

Prediction of successful trial of labor after cesarean among grand-multiparous women.

PURPOSE: To determine the factors associated with successful trial of labor after cesarean (TOLAC) among grand-multiparous (GMP) women. METHODS: A retrospective cohort study was conducted, including all GMP women (≥ 5 deliveries) undergoing TOLAC during 3/2011 and 6/2020, delivering a singleton cephalic newborn. Factors associated with successful vaginal delivery were examined by multivariable analysis. RESULTS: Overall, 381/413 (92.2%) GMP succeeded TOLAC. Maternal characteristics did not differ between TOLAC success and TOLAC failure groups. Previous cesarean delivery characteristics did not differ between study groups. The median number of previous vaginal births after cesarean was 2 [interquartile range 1-4]. Gestational age at TOLAC was lower in the success group (mean 371/7 ± 36/7 vs. 385/7 ± 31/7 weeks, p = 0.028). A lower rate of modified Bishop score < 4 was associated with TOLAC success [149 (39.1%) vs. 22 (69%), odds ratio (OR) 95% confidence interval (CI) 0.29 (0.13-0.64), p = 0.001]. The rate of induction of labor was higher in the TOLAC failure group [120 (31.5%) vs. 17 (53%), OR 95% CI 0.40 (0.19-0.83), p = 0.013]. The rate of oxytocin administration was higher in the TOLAC failure group [94 (24.7%) vs. 15 (47%) OR (95% CI) 0.37 (0.17-0.77), p = 0.006]. The duration of rupture of membranes was negatively associated with TOLAC success. Neonatal and maternal adverse outcomes did not differ between study groups. In multivariable logistic regression analysis, only the duration of rupture of membranes and modified Bishop score < 4 were independently associated with TOLAC success [adjusted OR (95% CI) 0.98 (0.96-0.99), p = 0.027 and 0.40 (0.16-0.97), p = 0.044]. CONCLUSION: TOLAC among GMP has a very-high success rate. Shortening the duration of ruptured membranes is a modifiable factor that may be associated with increased TOLAC success rates.

Uterine rupture risk in a trial of labor after cesarean section with and without previous vaginal births.

PURPOSE: Previous cesarean delivery (CD) is the main risk factor for uterine rupture when attempting a trial of labor. Previous vaginal delivery (PVD) is a predictor for the trial of labor after cesarean (TOLAC) success and a protective factor against uterine rupture. We aimed to assess the magnitude of PVD as a protective factor from uterine rupture. METHODS: A retrospective cohort study was conducted, including women who underwent TOLACs from 2003 to 2015. Women with and without PVD were compared. Inclusion criteria were one previous CD, trial of labor at ≥ 24 weeks' gestation, and cephalic presentation. We excluded pre-labor intrauterine fetal death and fetal anomalies. The primary outcome was a uterine rupture. Secondary outcomes were maternal and fetal complications. Logistic regression modeling was applied to analyze the association between PVD and uterine rupture while controlling for confounders. RESULTS: A total of 11,235 women were included, 6795 of which had a PVD. Women with PVD had significantly lower rates of uterine rupture (0.18% vs. 1.1%; OR 0.19, p < 0.001), were less likely to be delivered by an emergency CD (13.2% vs. 39.4%, OR 0.17, p < 0.0001), were more likely to undergo labor induction (OR 1.56, p < 0.0001), and were less likely to undergo an instrumental delivery (OR 0.14, p < 0.001). Logistic regression modeling revealed that PVD was the only independent protective factor, with an aOR of 0.22. CONCLUSION: PVD is the most important protective factor from uterine rupture in patients undergoing TOLAC. A trial of labor following one CD should therefore be encouraged in these patients.

Risk factors and outcomes associated with type of uterine rupture.

PURPOSE: To identify risk factors associated with the occurrence of complete uterine rupture (CUR) in comparison to partial uterine rupture (PUR) to further investigate to what extent a standardized definition is needed and what clinical implications can be drawn. METHODS: Between 2005 and 2017 cases with CUR and PUR at Charité University Berlin, Germany were retrospectively identified. Demographic, obstetric and outcome variables were analyzed regarding the type of rupture. Binary multivariate regression analysis was conducted to identify risk factors associated with CUR. In addition, the intended route of delivery (trial of labor after cesarean delivery (TOLAC) and elective repeat cesarean delivery (ERCD)), divided according to the type of rupture, was compared. RESULTS: 92 cases with uterine rupture were identified out of a total of 64.063 births (0.14%). Puerperal complications were more frequent in CUR (67.9 versus 41.1%, p = 0.021). Multiparity ≥ 3 was more frequent in CUR (31 versus 10.7%, p = 0.020). Factors increasing the risk for CUR were parity ≥ 3 (OR = 3.8, p = 0.025), previous vaginal birth (OR = 4.4, p = 0.011), TOLAC (OR = 6.5, p < 0.001) and the use of oxytocin (OR = 2.9, p = 0.036). After multivariate analysis, the only independent risk factor associated with CUR was TOLAC (OR = 7.4, p = 0.017). CONCLUSION: TOLAC is the only independent risk factor for CUR. After optimized antenatal counselling TOLAC and ERCD had comparable short-term maternal and fetal outcomes in a high resource setting. A high number of previous vaginal births does not eliminate the risk of uterine rupture. A clear distinction between CUR and PUR is essential to ensure comparability among studies.

Higher risk of hemorrhage and maternal morbidity in vaginal birth after second stage of labor C-section.

PURPOSE: This study evaluated the association between timing and indication for previous cesarean section (C-section) and its association with postpartum risks for adverse maternal outcomes, primarily postpartum hemorrhage (PPH) in vaginal birth after cesarean (VBAC). METHODS: This retrospective case-control study examined women following term vaginal delivery in a university-affiliated medical center between 2008 and 2018. Postpartum complications were compared between women who had their first VBAC and a control group comprised of women who had vaginal delivery without prior C-section. Additional analysis was performed to evaluate the association between the timing of previous C-section and the severity of postpartum adverse outcomes. RESULTS: Of the women meeting the inclusion criteria (n = 2879), 1,455 had VBAC and 1,424 were in the control group. Overall, significant postpartum complications, primarily PPH, were observed in the VBAC group compared to controls. Women who underwent C-section during second-stage of labor experienced higher PPH rates and increased drop in hemoglobin levels compared to women who underwent C-section during the first stage of labor or an elective C-Sect. (4.3 ± 0.9 g/dL vs. 2.8 ± 1.1 g/dL vs. 2.4 ± 0.8, p = 0.033). Concomitant increased need for blood transfusion (8.1% vs. 3.5% vs. 2.9%, respectively, p < 0.0001) and uterine atony (12.6% vs. 6.2% vs. 4.4%, respectively, p = 0.009) were also observed. No significant differences were demonstrated in other postpartum adverse effects evaluated. CONCLUSION: VBAC is associated with higher rates of postpartum complications, primarily PPH. The risk is significantly increased in VBAC following a second stage cesarean section. This data should be taken into consideration in the management of laboring women after C-section.

Balloon catheter vs oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix: a multicenter, retrospective study.

PURPOSE: To compare the rate of vaginal birth between double-balloon catheter and oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix. MATERIALS AND METHODS: A retrospective and observational study was conducted from 2013 to 2017, at the Saint-Etienne University Hospital where women received induction with a double-balloon catheter for 12 h and at the Grenoble Alpes University Hospital where women received induction with a low-dose oxytocin infusion. Primary outcome was the rate of vaginal birth. RESULTS: Out of 1920 women eligible for attempting a vaginal birth after one previous cesarean section, 501 had a labor induction. Among women with an unfavorable cervix, 160 received a double-balloon catheter in Saint Etienne and 152 received oxytocin alone in Grenoble. The vaginal birth rate was higher in the double-balloon catheter group (61% versus 47% in the oxytocin group). An induction of labor with oxytocin alone reduced chances of vaginal birth (aOR 0.38 CI-95% [0.22-0.66]) compared to cervical ripening with double-balloon catheter. The perinatal morbidity was similar in the two groups. There was, however, 3.9% uterine rupture in the oxytocin group versus 0.6% in the double-balloon group (p = 0.11). CONCLUSION: For induction of labor in women with one previous cesarean section and with unfavorable cervix, cervical ripening with a double-balloon catheter increases the rate of vaginal birth without increased risk of uterine rupture.

Factors associated with the outcome of TOLAC after one previous caesarean section: a retrospective cohort study.

The factors associated with the outcome of trial of labour after one previous Caesarean Section; a retrospective cohort study. A retrospective observational study was performed on all eligible consecutive singleton pregnancies planned for trial of labour after one previous Caesarean Section (TOLAC) over a period of 18 months to study the success rate of vaginal birth after Caesarean Section (VBAC) and to find out the factors associated with successful and failed TOLAC. All of the data were entered in electronic format and the data was analysed in detail. Of the 1324 women studied, the VBAC rate was 65.3% and the incidence of scar rupture was 0.5%. The composite adverse maternal (postpartum haemorrhage and intensive care admission) and foetal outcome (still birth, 5-minute APGAR <7 and NICU admission) was more in the failed TOLAC group. Various demographic, clinical and obstetric factors were studied in detail between the successful and failed TOLAC groups. The favourable Bishop Score (>4) was independently associated with successful TOLAC (OR 4.3; 95% CI 3.3-5.6 p < .001). Maternal age of >30 years, (OR 0.57; 95% CI 0.41-0.79; p = .001), labour induction (OR 0.43; 95% CI 0.33-0.56; p < .001) and estimated foetal weight of >3500 g (0.31; 95% CI 0.14-0.6; p = .002) were the factors independently associated with failed TOLAC. Previous indication for a Caesarean Section and previous vaginal delivery were not found to be independently associated with the outcome of TOLAC. The predictive models for TOLAC need to be used cautiously and the risk assessment should be done on an individual basis.IMPACT STATEMENTWhat is already known on this subject? TOLAC is a reasonable strategy in Obstetrics especially after one Caesarean Section to minimise the morbidity associated with rising Caesarean Section. However, the maternal and foetal morbidity are more following unsuccessful TOLAC. The factors which predict the outcome of TOLAC are multifactorial which include maternal demographic factors, previous obstetric factors like indication for Caesarean Section, intraoperative complications, inter-pregnancy interval, current obstetric factors such as gestational age, Bishop Score before delivery, labour factors and foetal factors, e.g. sex and foetal size.What do the results of this study add? We tried to include all the possible factors which probably influence TOLAC and found only Bishop Score, maternal age, foetal size and labour induction were the factors independently associated with the outcome of TOLAC. A Bishop Score of >4 admission was the greatest predictor of successful TOLAC (OR 4.3). Similarly, labour induction and foetal size of >3.5 kg were associated with 60% and 70% less chance of VBAC, respectively.What are the implications of these findings for clinical practice and/or further research? The factors found to be associated with successful and failed TOLAC may be utilised to develop a predictive model. More so, prospective studies are needed to test such predictive models.