Trial Of Labor After Cesarean Research Articles

Induction of Labor with Vaginal Dinoprostone (PGE2) in Patients with a Previous Cesarean Section: Obstetric and Neonatal Outcomes.

Background: Vaginal dinoprostone (PGE2) is currently used as the prostaglandin of choice in many obstetric units. However, few studies have evaluated its safety, especially in women who previously had a cesarean section. Objective: To evaluate the efficacy and safety of PGE2 in pregnant women who are undergoing induction of labor (IOL), and who have had a previous cesarean section. Materials and Methods: A prospective observational study was conducted in La Mancha Centro Hospital in Alcázar de San Juan, Spain, from 1 February 2019 to 30 August 2020. Obstetric and neonatal outcomes, following IOL with PGE2, in 47 pregnant women who wanted a trial of labor after cesarean (TOLAC), and 377 pregnant women without a history of cesarean section, were analyzed. The outcomes were analyzed by bivariate and multivariate analyses using binary and multiple linear regression. Results: A total of 424 women were included in this study. The percentage of cesarean sections in the TOLAC group was 44.7% (21), compared with 31.6% (119) in the group without a history of cesarean section (adjusted odds ratio: 1.4; 95% CI: 0.68–2.86). In the multivariate analysis, no statistically significant differences were observed between both groups for obstetric and neonatal outcomes (p > 0.05). However, two uterine ruptures (4.3%) occurred in the group of patients with a history of cesarean section who underwent IOL with PGE2. Conclusions: The induction of labor with vaginal dinoprostone (PGE2), in patients with a previous history of cesarean section, was not associated with worse obstetric or neonatal outcomes compared with the group of patients without a history of cesarean section in our study sample. However, further research is needed regarding this IOL method, and it should be used with caution in this population group.

Trial of labor after cesarean in primiparous women with fetal macrosomia.

Spontaneous labor onset, epidural anesthesia and prior cesarean for non-arrest disorders are strong predictors of successful vaginal birth after cesarean in women delivering a macrosomic fetus. Lower rates of successful vaginal birth after cesarean in association with increasing birthweight were previously reported. We aimed to determine the factors associated with successful trial of labor after cesarean (TOLAC) among primiparous women with fetal macrosomia. A retrospective cohort study conducted during 2005-2019 at two university hospitals, including all primiparous women delivering a singleton fetus weighing ≥ 4000g, after cesarean delivery at their first delivery. A multivariate analysis was performed to evaluate the characteristics associated with TOLAC success (primary outcome). Of 551 primiparous women who met the inclusion criteria, 50.1% (n = 276) attempted a TOLAC and 174 (63.0%) successfully delivered vaginally. In a multivariate analysis, spontaneous onset of labor (aOR [95% CI] 3.68 (2.05, 6.61), P < 0.001), epidural anesthesia (aOR [95% CI] 2.38 (1.35, 4.20), P = 0.003) and history of cesarean delivery due to non-arrest disorder (aOR [95% CI] 2.25 (1.32, 3.85), P = 0.003) were the only independent factors associated with TOLAC success. Successful TOLAC was achieved in 82.0% (82/100) in the presence of all three favorable factors, 61.3% (65/106) in the presence of two factors and 38.6% (27/70) in the presence of one or less of these three factors (P < 0.001). Spontaneous onset of labor, epidural anesthesia and prior cesarean delivery due to non-arrest disorders were independently associated with higher vaginal birth after cesarean rate among women with fetal macrosomia, with an overall favorable success rate in the presence of these factors. These findings should be implemented in patient counseling in those contemplating a vaginal birth in this setting.

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

To determine the factors associated with successful trial of labor after cesarean (TOLAC) among grand-multiparous (GMP) women. 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. 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 ± 31/7weeks, 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]. 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.

Prediction of vaginal birth after cesarean for labor dystocia by sonographic estimated fetal weight.

To estimate the association of the weight difference between the index trial of labor after cesarean (TOLAC) sonographic estimated fetal weight (sEFW) and prior delivery birth weight with TOLAC success rate among women with previous labor dystocia and no prior vaginal delivery. A retrospective cohort study including all women with prior cesarean for labor dystocia and no prior vaginal delivery undergoing TOLAC during between March 2011 and June 2020 with a sEFW within 1week from delivery. Overall, 168 women were included, of those 107 (63.7%) successfully delivered vaginally. The mean sEFW and mean birth weight were lower in the TOLAC success group (P=0.010 and P=0.013, respectively). The rate of higher sEFW in the current delivery compared with the previous delivery did not differ between study groups. The rate of higher TOLAC birth weight was lower in the TOLAC success group (odds ratio 0.30; 95% confidence interval 0.15-0.58). In multivariable regression analysis, maternal age older than 30years, induction of labor, and higher birth weight were independently negatively associated with TOLAC success (adjusted odds ratio [95% confidence interval]: 0.27 [0.10-0.70], 0.27 [0.08-0.90], and 0.43 [0.19-0.94]; P=0.008, P=0.034, and P=0.035, respectively). sEFW characteristics did not predict the success or failure of TOLAC among women with prior labor dystocia and no previous vaginal delivery.

Patient decision aid for trial of labor after cesarean (TOLAC) versus planned repeat cesarean delivery: a quasi-experimental pre-post study

ObjectiveTo assess the impact of a web-based decision aid on patient-centered decision making outcomes among women considering a trial of labor after cesarean (TOLAC) versus planned repeat cesarean delivery.MethodsThe Birth Decision Aid Study (B-READY) was a quasi-experimental pre-post study of two sequential cohorts. From June 18, 2018 to July 31, 2019, 50 women were enrolled in routine care, followed by 50 women who were enrolled in the decision aid group. Inclusion criteria were singleton pregnancies between 19/0 to 36/6 weeks, ≤2 prior cesareans, and no contraindications to TOLAC. The decision aid group viewed the online Healthwise® “Pregnancy: Birth Options After Cesarean” program. Both groups received the same birth options counseling and completed the same online assessment. Primary patient-centered outcomes were knowledge about birth options and shared decision making at online assessment, and informed, patient-centered decision making about her preferred mode of delivery at delivery admission.ResultsAmong 100 women participated in this study (50 per group), the mean gestational age at enrollment was 31 weeks, and 71% or 63/89 women who consented to delivery data abstraction had a cesarean delivery. Women in the patient decision aid group gained more knowledge (defined as score ≥ 75%) about birth options compared to those in the routine care group (72% vs. 32%; adjusted odds ratio, AOR: 6.15 [95% CI: 2.34 to 16.14]), and were more likely to make an informed, patient-centered decision (60% vs. 26%; AOR: 3.30 [95% CI: 1.20 to 9.04]. Women in both groups reported similar involvement in shared decision making, as well as satisfaction and values. More than 90% of decision aid users reported it was a useful tool and would recommend it to other TOLAC-eligible women.ConclusionsA web-based birth options patient-centered decision aid for TOLAC eligible women can be integrated into prenatal Telehealth and may improve the quality of decision making about mode of delivery.Trial registrationThe study was registered with ClinincalTrials.gov and the ID# was NCT04053413. Registered 12 August 2019 – Retrospectively registered.

Prediction of successful preterm vaginal birth after cesarean among women who never delivered vaginally.

We aimed to determine the factors associated with a successful trial of labor after cesarean (TOLAC) in the setting of preterm delivery of women with no prior vaginal delivery. A retrospective cohort study conducted at two tertiary medical centers during 2010-2020, including all TOLACs with a single cesarean delivery and no prior vaginal delivery, delivering a singleton preterm newborn. Factors associated with successful vaginal delivery were examined by multivariable analysis. Of the 232 women with TOLAC who constituted the study cohort, 178 (76.7%) successfully delivered vaginally. Previous cesarean delivery characteristics did not differ between study groups. Maternal characteristics did not differ between TOLAC success and failure groups. The median gestational age at delivery was 35 3/7weeks (IQR 34 0/7-36 0/7). The rate of epidural analgesia administration was higher in the TOLAC success group (54.5% vs. 35%, p = 0.013). Preterm premature rupture of membranes (PPROM) rate was lower in the TOLAC success group (53.9% vs. 83%, p < 0.001). The rate of induction of labor did not differ between TOLAC success and TOLAC failure groups. There were no cases of uterine rupture. In a multivariable logistic regression analysis, PPROM was the only independent factor associated with TOLAC success [adjusted OR (95% CI) 0.29 (0.10-0.83), p = 0.030]. TOLAC in preterm deliveries among women with no prior vaginal delivery is safe, has a high success rate and PPROM is the only negatively associated predictor.

Risk management of vaginal birth after cesarean section (Review).

The increasing number of patients who desire to experience vaginal birth after cesarean (VBAC) and the optimized protocols for trial of labor after cesarean (TOLAC) has led to a shift of old obstetrical paradigms. The VBAC trend is accompanied with numerous challenges for healthcare professionals, from establishing suitability of each pregnant patient profile for TOLAC to active labor management, and ethical or legal issues, which occasionally are not included in specific guidelines. That is why an individualized risk assessment and management can serve obstetricians as a useful tool for improving outcomes of patients, satisfaction, and also for avoiding legal or moral liabilities. The risk management concept aims to reduce foreseen risks and to emulate strategies for prediction and prevention of unwanted events. In obstetrics, and particularly for the VBAC topic, this concept is relatively new and undefined, and thus its features are disparate between guideline recommendations and clinical studies. This narrative review intends to offer a new and organic perspective over clinical aspects of TOLAC and VBAC risk management.

Trial of Labor After Cesarean of Small for Gestational Age Neonates Among Women with No Prior Vaginal Delivery - a Retrospective Study.

To evaluate the characteristics and outcomes of women who had never delivered vaginally and underwent a trial of labor after cesarean (TOLAC) of small for gestational age (SGA) neonates, and to identify risk factors for unplanned repeat cesarean delivery. A retrospective cohort study from two tertiary medical centers. All women undergoing a TOLAC with no prior vaginal delivery, delivering a singleton SGA neonate at term between 2005 and 2020 were included. Factors associated with successful vaginal delivery were examined by a multivariable analysis. Of the 255 women who met the inclusion criteria and underwent TOLAC, 72.2% delivered vaginally. In a multivariable analysis, maternal height [adjusted odds ratio (aOR) (95% CI): 1.10 (1.02-1.19), p = 0.012] and epidural administration [aOR (95% CI): 2.78 (1.0-7.73), p = 0.050] were positively independently associated with TOLAC success, and hypertensive disorders were negatively independently associated with TOLAC success [aOR (95% CI): 0.52 (0.004-0.74), p = 0.029]. The success rate of TOLAC among women with no prior vaginal delivery, delivering a SGA neonate is relatively high. Maternal height, hypertensive disorders, and epidural administration are independent factors associated with TOLAC success. Epidural administration is a modifiable factor and should be taken in consideration during TOLAC management.

Prediction of successful vaginal birth after cesarean in women with diabetic disorders and no prior vaginal delivery.

To study the factors associated with successful trial of labor after cesarean (TOLAC) among women with diabetes and no prior vaginal delivery and compare with TOLAC in nondiabetic women. A retrospective study including all women undergoing TOLAC who had no prior vaginal delivery between March 2011 and June 2020 at Sheba Medical Center. Women with diabetic disorders were compared with those without. Multivariate regression analysis was performed to identify factors independently associated with TOLAC success. Of 2144 deliveries with TOLAC, 163 (7.6%) were to women with a diabetic disorder. TOLAC success rate was comparable between diabetic and nondiabetic women (124 [76.1%] vs 1513 [76.4%], respectively; P=0.931). Uterine rupture rate was 1.1% (23 out of 2144). Among women with diabetes the uterine rupture rate was 0.6% (1 out of 163) and did not differ between the success or fail TOLAC groups. Multivariate logistic regression showed that epidural anesthesia and cervical effacement were the only independent factors associated with TOLAC success in women with diabetes (adjusted OR 3.32; 95% CI, 1.31-8.69, P=0.011 and aOR 1.04; 95% CI, 1.01-1.07, P=0.007, respectively). TOLAC in women with diabetes with no prior vaginal delivery has a high success rate. Epidural analgesia is the only modifiable independent predictor of TOLAC success.

Racial/Ethnic Differences in Socioeconomic Status and Medical Correlates of Trial of Labor After Cesarean and Vaginal Birth After Cesarean.

Objectives: Black and Latinx women have higher rates of trial of labor after cesarean (TOLAC) compared with White women, but lower rates of vaginal birth after cesarean (VBAC). This study examined potential racial/ethnic differences in correlates of TOLAC and VBAC. Materials and Methods: The analytic sample includes term, singleton hospital births to women with one prior cesarean in birth certificate data for 2016. We estimated associations between medical factors (diabetes, hypertension, and prepregnancy obesity) and socioeconomic status (education level and insurance type) and TOLAC and VBAC using logistic regression, stratifying by race/ethnicity and testing whether coefficients differed across models. Results: Hypertension and obesity were more strongly related to reduced chances of TOLAC among White women than among women of color. For example, having a body mass index (BMI) between 30 and 39 (vs. normal BMI) was associated with a 6.3 percentage-point (pp) lower probability of TOLAC for White women, a 5.9 pp lower probability for Black women, and 2.9 pp lower probability for Latinx women. Paying out-of-pocket for birth was associated with a 5.5 pp increase in the probability of TOLAC among White women, versus a 3.2 pp decrease among Black women. Overweight and obesity were associated with lower probability of VBAC, but the magnitude of this association was smaller for Black and Latinx women than for White women. Conclusions: More research is needed to elucidate the underlying decision-making processes that lead to these associations. Future work should focus on ensuring equity in access to VBAC-supportive providers and hospitals and fostering informed decision-making after a prior cesarean.

Risk factors for obstetric anal sphincter injury among women undergoing a trial of labor after cesarean

ObjectiveData regarding the risks of obstetrical anal sphincter injury (OASI) among women who never delivered vaginally undergoing a trial of labor after cesarean (TOLAC) are scarce. We aimed to evaluate the risk factors and the rate of OASI among women undergoing TOLAC who never delivered vaginally. Study designA retrospective cohort study of all women undergoing a TOLAC and never delivered vaginally between 3/2011 and 6/2020. Maternal and intrapartum characteristics were compared between OASI and no-OASI groups. We matched groups to earliest gestational age in which OASI has occurred. A further comparison was made between the study cohort and a cohort of primiparous women undergoing a vaginal delivery, including gestational ages at which OASI has occurred in that cohort. ResultsDuring the study period there were 2061 TOLACs among women without prior vaginal delivery. Of these, 76 % (1566/2061) had a successful vaginal delivery. Overall, 22/2061 (1.1 %) cases of OASI occurred. There was no difference in maternal demographic, obstetrical and medical history characteristics between the study groups. The mean gestational age at TOLAC was lower in the OASI group (390/7 ± 12/7 vs. 395/7 ± 12/7, p = 0.012). In multivariable regression analysis, gestational age was negatively associated with OASI [adjusted odds ratio, 95 % (confidence interval) 0.95 (0.91-0.99), for each day increase in gestational age)]. The rate of OASI in the study cohort did not differ from the rate of OASI among primiparous women during the same study period (347/27975, 1.2 %, p = 0.686). ConclusionGestational age at delivery is the only predictor of OASI among women with no prior vaginal deliveries undergoing a TOLAC. The incidence of OASI in this population is 1.1 % and does not differ from that of primiparous women.

Third-trimester Prediction of Successful Vaginal Birth After One Cesarean Delivery: A Swedish Model

(Acta Obstet Gynecol Scand. 2020;99:660–668) In women with one previous cesarean delivery (CD), the decision to deliver by cesarean or trial of labor can be a difficult one. In Sweden, ∼75% of women choosing a trial of labor after cesarean (TOLAC) would have a successful vaginal birth after cesarean (VBAC). The study aimed to adapt and validate a US prediction model for use in Sweden, adding several important factors and the rate of VBAC in TOLAC for the specific delivery ward.

909 Obstetric outcomes among women who underwent TOLAC versus repeat cesarean

Women with a prior cesarean must make an informed choice between a repeat cesarean versus a trial of labor after cesarean (TOLAC). The objective of this study was to determine the differences in maternal and infant outcomes in women who underwent repeat cesarean delivery (CD) without TOLAC versus women who underwent TOLAC. This was a retrospective cohort study of women delivering in California between 2007-2011 who were delivering after a previous cesarean. The study included women with singleton, non-anomalous, multiparous live births between 37- and 41-weeks’ gestation. We examined rates of maternal and infant outcomes. Analyses were conducted using Pearson’s chi-squared test of significance with an alpha of 0.05. In this study, 345,308 women-infant dyads met the inclusion criteria. Of these, 296,457 (85.9%) had a repeat cesarean section without TOLAC and 48,851 (14.1%) underwent TOLAC. Maternal and infant outcomes were significantly different between groups. Rates of endometritis were lower in women with a repeat cesarean without TOLAC than those who had a trial of labor (0.4% vs. 0.6%, p<0.001). Women who did not undergo TOLAC experienced lower rates of postpartum hemorrhage compared to those who did (1.2% vs. 3.1%, p<0.001), though the experienced a higher rate of blood transfusion (1.0% vs. 0.9%, p<0.001). Infants of women in the TOLAC group had higher rates of neonatal intensive care unit admission (7.2% vs. 5.6%, p<0.001) and higher rates of APGAR scores under 7 at five minutes (0.5% vs. 0.3%, p <0.001). Infants of women in the TOLAC group were also more likely to have hypoxic-ischemic encephalopathy (0.1% vs. 0.02%, p<0.001). There was no significant difference in neonatal death. We found that, when comparing undergoing repeat cesarean with and without TOLAC, maternal and infant outcomes were significantly different. Future research should investigate characteristics and management factors contributing to these differences.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

342 Quality improvement initiative to improve patient counseling using calculated vaginal birth after cesarean success likelihood

Successful vaginal birth after cesarean (VBAC) has lower morbidity compared to a failed trial of labor after cesarean (TOLAC). The Maternal Fetal Medicine Units Antepartum VBAC Calculator uses demographics and history to predict likelihood of successful TOLAC. Prior studies have identified a threshold VBAC success probability of < 60% to result in increased risk for TOLAC-related morbidity. We implemented formal incorporation of the VBAC probability score into counseling of patients considering TOLAC, with the goal of decreasing the rate of cesarean delivery (CD) in women attempting TOLAC. At a single tertiary care center, use of an institutional “TOLAC Consult” electronic medical record smartphrase, with embedded VBAC probability calculation, was implemented in January 2019. The decision for intended mode of delivery (even with induction) was ultimately made by the patient. Prospective data were collected through April 2020 (n=321) and compared to a historical cohort dating back to January 2016 (n=693). All patients eligible for TOLAC with one or two prior CD were included. The primary process measure was high-risk induction rate, defined as percent of those with <60% probability of successful VBAC who underwent induction for TOLAC. The primary outcome measure was the rate of labored CD in this population, while the balancing measure was overall VBAC rate. Cohorts were demographically similar, though fewer in the prospective group had history of an arrest disorder (38% vs 48%, p=0.005). Among patients with VBAC probability <60%, induction rates decreased from 17% to 5% (Table 1). Labored CD rates also decreased from 15% to 10% (Figure 1), while overall VBAC rate remained unchanged from 32% to 34%. Succesful TOLAC rate improved from 68% to 77% (p=0.01). Formal incorporation of VBAC success probability into the TOLAC consultation process correlated with a decrease in induction of labor among those at elevated risk of morbidity, as well as decreased rates of labored CD, without decreasing the overall VBAC rate.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

449 Fetal head station at second stage dystocia- does it predict subsequent TOLAC success rate?

The factors associated with successful trial of labor after cesarean (TOLAC) among women with prior cesarean delivery (CD) for second-stage dystocia remain largely unestablished. We aimed to determine whether fetal head station at the index CD predicts the success rate of subsequent trial of labor among primiparous women. A retrospective cohort study conducted at two tertiary, university affiliated medical centers, including all primiparous women with subsequent delivery after CD for second-stage dystocia during 2009-2019. Overall, 481 primiparous women with prior CD for second-stage dystocia, had a subsequent delivery during study period. Of them, 171 (35.6%) women had an elective repeat CD and 310 (64.4%) attempted a TOLAC. Those undergoing TOLAC were younger (P<0.001), with lower rates of hypertensive disorders (P=0.005) and gestational diabetes (P=0.003) at the subsequent pregnancy. Of those undergoing TOLAC (n=310), 222 (71.6%) successfully delivered vaginally. The rate of successful TOLAC was significantly higher in those with fetal head station below the ischial spines at the index CD as compared to those with higher head station (79.0% vs. 60.5%, P<0.001). The proportion of infants weighing >3,500 grams in the subsequent delivery was lower in those with successful compared with failed TOLAC (29.7% vs. 43.2%, OR [95% CI]: 0.56 (0.33-0.93), P=0.03). In a multivariable analysis, lower fetal head station at the index CD was the only independent factor associated with TOLAC success (aOR [95% CI]: 2.38 (1.43, 3.96), P=0.001). Lower fetal head station at the index CD for second-stage dystocia was independently associated with higher VBAC rate, with an overall acceptable success rate. These findings should improve patient counseling and reassure those who wish to delivery vaginally after prior second-stage arrest.

1153 Influence of race on adverse perinatal outcomes in women undergoing TOLAC

To examine the association between race and adverse maternal and neonatal outcomes in women who undergo Trial of Labor after Cesarean (TOLAC). This is a retrospective cohort study of singleton non-anomalous pregnancies between 2007 and 2011 using linked vital statistics and discharge data. Chi-square tests were used to compare rates of adverse outcomes for women who underwent TOLAC categorized by race. Multivariable logistic regression was used to control for several factors including race. Race was categorized into six categories of White (Non-Hispanic), Black, Hispanic, Asian, American Native, and Other. The adverse maternal outcomes examined were postpartum hemorrhage (PPH), perineal lacerations, chorioamnionitis, maternal blood transfusion, placental abruption, severe maternal morbidity (SMM), and endomyometritis. The neonatal outcomes examined were infant death, neonatal death (NND), intrauterine fetal death (IUFD), Neonatal Intensive Care Unit (NICU) admission, birth injuries, brachial plexus injury (BPI), hypoxic ischemic encephalopathy (HIE), clavicle fracture, and skull fracture. The cohort consisted of 362,270 pregnancies with a prior CD, 29,628 pregnancies resulted in TOLAC. The cohort of 2,699,312 women consisted of 36,195 TOLAC, 29,638 of which were singleton non-anomalous pregnancies. After controlling for several confounders of interest there was a statistically significant increase in PPH, lacerations, chorioamnionitis, maternal blood transfusions, SMM, endomyometritis, infant death and birth injuries in Asian Women. There was a statistically significant increase in chorioamnionitis and HIE as well as a decrease in lacerations in Black Women. There was a statistically significant increase in chorioamnionitis and endomyometritis in Hispanic women as well as a decrease in infant death (Table 1). Different racial backgrounds increase the risk of maternal and neonatal complications in the settings TOLAC. Practitioners should exercise heightened awareness of the effect of race on these potential adverse outcomes when managing TOLAC.

775 Racial and ethnic disparities in rates and success of trial of labor after cesarean

The Maternal-Fetal Medicine Units Network vaginal birth after cesarean (VBAC) calculator is widely used to predict success of trial of labor after cesarean (TOLAC). Predictor variables include race and ethnicity, raising concerns that this calculator is widening disparities in cesarean section rates. Our aim was to assess racial and ethnic disparities in rates of TOLAC. This is a population-based retrospective cohort study using National Center for Health Statistics live birth data between 2014 and 2018. Women who delivered a cephalic, singleton gestation, ≥ 37 weeks with a history of one prior cesarean section were included. TOLAC rates were calculated by race/ethnicity and stratified by insurance status. The primary outcome was rate of TOLAC by race/ethnicity. The secondary outcome was rate of VBAC among groups. Multivariate logistic regression was performed to adjust for BMI, maternal age, prior vaginal delivery and insurance status. 1,481,898 women met inclusion criteria; 57.3% Non-Hispanic White (NHW), 16.0% Non-Hispanic Black (NHB), 26.6% Hispanic. TOLAC rates were highest in NHB women (26.5% versus NHW 22.5% and Hispanic 23.1%; p<.001). Medicaid patients had higher rates of TOLAC compared to privately insured patients 23.5% vs 21.7% (p<0.001). For NHW women with Medicaid, rate of TOLAC was 20.9% vs 22.1% for private insurance (p<0.001), compared to NHB women 27.9% vs 22.5% (p<0.001), and Hispanic women (23.5% vs 19.8%, p<0.001). After adjustment, odds of TOLAC were similar in NHB (OR 1.01 95% CI 0.99-1.03), but lower in Hispanic women (OR 0.87 95% CI 0.85 – 0.88) compared to NHW women. Successful VBAC was significantly lower among NHB (OR 0.54 95% CI 0.52 – 0.56) and Hispanic (OR 0.84 95% CI 0.81-0.88) women compared to NHW women. Despite similar TOLAC rates between NHB and NHW women, VBAC is significantly lower in NHB women. Hispanic women have lower TOLAC and VBAC rates than NHW women. Race/ethnicity and tools that include this predictor may influence management of TOLAC and contribute to the disparity in cesarean section rate.

939 Trial of labor vs. repeat cesarean delivery in sub-saharan africa: a systematic review and metanalysis

Recent data points to a high risk of morbidity and mortality around cesarean delivery (CD) in sub-Saharan Africa (SSA). Women with a prior CD carry higher risks in subsequent pregnancies, yet there is no recent synthesis on the optimal management of this population in SSA. We aimed to assess rates of trial of labor after cesarean (TOLAC) and elective repeat cesarean (ERCD) and associated outcomes among women with a prior CD in SSA. We searched PubMed, MEDLINE, CAB, EMBASE, African Index Medicus, and CINAHL databases from inception until July 2020. We included studies from SSA of women with a prior CD where TOLAC and ERCD rates were reported as well as maternal and perinatal outcomes. Studies in which outcomes were not reported by initial management strategy were excluded. We summarized TOLAC, vaginal birth after cesarean (VBAC) and ERCD rates. The primary outcome was uterine rupture and secondary outcomes were maternal and perinatal mortality. We calculated the pooled TOLAC and VBAC rates, and relative risks of adverse outcomes with 95% confidence intervals. We assessed quality with the Methodological Index for Non-Randomized Studies (MINORS). Twelve studies met inclusion criteria (Figure 1). This represents 20,790 women, 9,501 births in 9 countries with study dates from 1972 to 2017. The pooled TOLAC rate was 68%, ranging from 22% to 98%. The median VBAC rate was 33%, ranging from 2.4% to 84%. Pooled outcome rates and odds ratios are presented in Figure 2. There were no differences in outcomes between groups. The median MINORS score was 18 (range 17-19.5). No study met the MINORS ideal score of 24. TOLAC and VBAC rates vary widely in SSA, with no difference in outcomes by management strategy. However, the inadequately powered studies and inconsistent reporting limit the ability to draw conclusions. In light of increasing CD rates in SSA, there is an urgent need for larger well-designed studies to understand the role of TOLAC vs ERCD in SSA and optimal management strategies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

624 Uterine rupture in women with a prior cesarean delivery: labor characteristics

Uterine rupture in women undergoing trial of labor after cesarean (TOLAC) has been associated with labor induction and length. Contemporary definitions of normal labor progress, based on data collected by the Consortium on Safe Labor and depicted by Zhang’s partogram, allow for longer labor duration, but excluded women with a uterine scar. Here, we present labor characteristics of TOLACs complicated by uterine rupture, in the context of contemporary labor management guidelines. This is an observational study of all clinically significant uterine ruptures in women undergoing TOLAC from 2009-2019 at a single tertiary academic center. ICD9/10 code search was used to identify TOLACs complicated by obstetric trauma and/or maternal morbidity, followed by electronic chart review to confirm diagnosis and collect demographic, pregnancy, and labor characteristics. For women with active phase or 2nd stage arrest, the rate of cervical change prior to uterine rupture (1st stage rupture), or prior to complete cervical dilation (2nd stage rupture) was collected and compared to the median and 95th % of Zhang’s partogram. There were 21 uterine ruptures in 1128 TOLACs (1.86%). Table 1 demonstrates maternal and pregnancy characteristics. Most women were induced or augmented (76% and 9.5%, respectively). Uterine ruptures in latent phase, active phase and 2nd stage were similarly distributed. There were no women with prolonged latent phase or second stage. However, the rate of cervical change prior to rupture or prior to complete cervical dilation was beyond the expected median for hourly change 86.7% of the time, though within the 95th% of the Zhang curve in 46.7% of cases (Figure 1). Most women undergoing TOLAC who experienced uterine rupture were exposed to oxytocin, and, when in active phase, demonstrated longer than average hourly cervical change. Contemporary labor management guidelines allowing for longer duration of labor may not be appropriate for patients undergoing TOLAC, particularly in the context of oxytocin administration.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

1165 How does VBAC success rates vary by race/ethnicity?

To examine the association between race/ethnicity and successful vaginal birth after cesarean (VBAC). This is a retrospective cohort study of women with singleton non-anomalous pregnancies between 2007 and 2011 using linked vital statistics and discharge data. Chi-square tests were used to compare rates Trial of Labor After Cesarean (TOLAC) to repeat Cesarean Delivery (CD) of women who had a previous CD as well as rates of successful VBAC from women who underwent TOLAC categorized by race. A multivariable regression was also conducted to control for several factors including race to analyze successful vaginal delivery rates. Race was categorized into six categories consisting of White (Non-Hispanic), Black (Non-Hispanic), Hispanic, Asian (Non-Hispanic), American Native (Non-Hispanic), and Other (Non-Hispanic). The cohort consisted of 343,410 pregnancies with a prior CD, 49,100 pregnancies (14.30%) resulted in TOLAC. Patients identifying as Hispanic had the lowest rate of women undergoing TOLAC (13.33%). Women who identified as Asian had the highest rate of women undergoing TOLAC (16.82%). Of the pregnancies that underwent TOLAC, 35,147 pregnancies (71.58%) resulted in a successful VBAC. Patients identifying as American Native had the lowest rate of successful VBAC (56.21%). Patients identifying as Black (Non-Hispanic) had the highest rate of successful VBAC (72.40%). While many of the proportions of successful VBAC were similar, when controlling for race a statistically significant increase was seen in rates of VBAC in Black women as well as a statistically significant decrease in rates of VBAC in American Native women. Hispanic women had the lowest rate of women undergoing TOLAC and American Native women had the lowest rate of a successful VBAC after TOLAC. Black women had marginally higher rates of successful VBAC, however, when controlling for confounders there was actually a 23% increase in successful VBAC.View Large Image Figure ViewerDownload Hi-res image Download (PPT)