Vaginal Birth After Cesarean Rates Research Articles

Observed Versus Predicted Vaginal Birth After Cesarean for Patients of a Community Health Center.

The Maternal-Fetal Medicine Units Network calculator for vaginal birth after cesarean (VBAC) probability was updated to exclude a race and ethnicity variable, but its impact on marginalized groups is unknown. We assessed the tool with attention to birth history and body mass index (BMI) in a predominately Hispanic cohort and examined the possible effect of discouraging labor after cesarean (LAC) with a low score. We conducted a retrospective cohort study of LACs by patients who entered spontaneous or induced labor with a live, nonanomalous fetus in cephalic presentation between 2012 and 2022. Observed VBAC rates were compared with the mean predicted VBAC probability derived from the calculator. Areas under the curve (AUCs) were calculated for the entire cohort and for individuals with LAC with and without prior vaginal birth. A z-test was used to determine the significance between VBAC rates in 4 BMI categories. The impact of discouraging LAC with VBAC probability below 70% was examined. A total of 400 people experienced 507 LACs, with 417 (82.2%) resulting in VBAC compared with a mean predicted probability of 71.2%. The AUC for all LACs was 0.76 (95% CI, 0.71-0.81), whereas the AUC for LACs with prior vaginal birth was 0.70 (95% CI, 0.56-0.85) and without was 0.60 (95% CI, 0.52-0.67). Observed VBAC rates exceeded predicted rates for individuals with overweight and obese BMIs: <25 (79.6% vs 75.6%; P =.520), 25 to 30 (83.2% vs 71.9%; P =.007), 30 to 40 (82.7% vs 70.0%; P =.004), and ≥40 (82.8% vs 58.3%; P =.040). Discouraging LAC below 70% probability might have prevented 71 unsuccessful LACs, 160 initial VBACs, and 57 subsequent VBACs, decreasing the VBAC rate to 39.4% (200/507). In a predominately Hispanic cohort, the updated calculator underestimated VBAC potential for people with no vaginal birth history and/or an elevated BMI. Discouraging LAC based on low VBAC probability may prevent both initial and subsequent VBACs.

Exploring Effect of Patient Counseling on Mode of Delivery After Cesarean Section [ID 2683575

INTRODUCTION: Increasing vaginal birth after cesarean (VBAC) may help lower national cesarean delivery rates in the United States. This study aims to evaluate factors that affect counseling practices and trial of labor after cesarean (TOLAC). METHODS: All term repeat cesarean deliveries (rCDs) and VBACs from September 2018 to February 2020 were reviewed. Antepartum counseling on mode of delivery, demographic, and obstetrical data were collected. Patients who were not TOLAC candidates were excluded. This study was IRB approved. RESULTS: Six hundred thirty-five patients met inclusion criteria. 304 (47.72%) of these patients had rCD, 65 (10.20%) attempted TOLAC with subsequent rCD, and 268 (42.07%) had VBAC. Of the 635 patients, 470 (74.02%) patients had documentation of TOLAC counseling prior to admission for delivery, whereas 165 (25.98%) did not. TOLAC counseling documentation was not associated with age, race, ethnicity, body mass index (BMI), insurance type, or history of vaginal delivery (VD). Prior VBAC increased the odds of documented TOLAC counseling (odds ratio [OR] 2.36; 95% CI, 1.29–4.63). Medicaid insurance (OR 2.18; 95% CI, 1.29–3.73), history of VD (OR 2.28; 95% CI, 1.16–4.68), history of VBAC (OR 269.0; 95% CI, 50.2–5079), and documented TOLAC counseling (OR 21.12; 95% CI, 11.0–45.10) increased the odds of TOLAC. Increasing BMI decreased the odds of TOLAC (OR 0.91; 95% CI, 0.89–0.95). CONCLUSION: Documented TOLAC counseling increased the odds of attempting TOLAC. As only 74.02% of patients had documented counseling prior to admission for delivery, an effort to increase TOLAC counseling and documentation may increase TOLAC and subsequent VBAC rates, decreasing the cesarean delivery rate.

Effect of excessive gestational weight gain before and after 28 weeks on trial of labor after cesarean stratified by pre-pregnancy body mass index: a retrospective cohort study.

This study aimed to assess the effect of excessive gestational weight gain (GWG) before and after 28 weeks on the mode of delivery in women who attempted a trial of labor after cesarean (TOLAC), stratified by pre-pregnancy BMI. A retrospective analysis of the outcomes of eligible women who attempted trial of labor after cesarean (TOLAC) in a Chinese hospital from January 2016 to October 2022 was performed. GWG before and after 28 weeks was categorized as 'excessive' or 'non-excessive' based on the guideline of Institute of Medicine (IOM). Multivariable logistic regression analyses were used to estimate the effect of excessive GWG before and after 28 weeks on mode of delivery in women who underwent TOLAC, stratified by pre-pregnancy BMI. Of the 512 women who underwent term trial of labor, 71.1% achieved a vaginal birth. No correlation was found between excessive GWG before 28 weeks and the rate of vaginal birth after cesarean (VBAC). Among women with or without excessive GWG before 28 weeks, excessive GWG after 28 weeks was significantly associated with a reduced rate of VBAC. When stratified by pre-pregnancy BMI, women who had excessive gestational weight gain after 28 weeks gestation had lower rates of VBAC than those who did not, regardless of being underweight, normal or overweight (aOR 0.23, 95% CI 0.06-0.88; aOR 0.42, 95% CI 0.25, 0.70; and aOR 0.12, 95% CI 0.04-0.36; respectively). Excessive weight gain after 28 weeks of pregnancy was related to decreased rates of VBAC, irrespective of pre-pregnancy weight status and weight gain before 28 weeks.

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

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. 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. 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). 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.

Induction of Labor in Women with Previous Cesarean Section and Unfavorable Cervix: A Retrospective Cohort Study.

Background: The efficacy and safety of a cervical ripening balloon (CRB) in women with a previous cesarean section (CS) and unfavorable Bishop score are still controversial. Methods: A retrospective cohort study was performed across six tertiary hospitals from 2015 to 2019. Women with one previous transverse CS, singleton cephalic term pregnancy and BS < 6 were included if submitted to labor induction with a CRB. The main outcome was the rate of vaginal birth after cesarean (VBAC) after CRB ripening. Secondary outcomes were abnormal composite fetal and maternal outcomes. Results: Of the 265 women included, 57.3% had successful vaginal birth. Augmentation improved vaginal delivery (32.2% vs. 21.2%). Intrapartum analgesia was associated with an increased VBAC rate (58.6% vs. 34.5%). Maternal BMI ≥30 and age ≥40 years increased emergency CS rate (11.8% vs. 28.3% and 7.2 vs. 15.9%). Composite adverse maternal outcome occurred in 4.8% of CRB group women and increased to 17.6% when associated with oxytocin. Uterine rupture occurred in one case (0.4%) in the CRB-oxytocin group. Poorer fetal outcome occurred after emergency CS, if compared to successful VBAC (12.4% vs. 3.3%). Conclusions: In women with a previous CS and unfavorable Bishop score, induction of labor with a CRB can be considered safe and effective.

Association Between Utilization of Digital Prenatal Services and Vaginal Birth After Cesarean.

Digital health services are a promising but understudied method for reducing common barriers to vaginal birth after cesarean (VBAC), including connection to facilities offering labor after cesarean and patient-centered counseling about mode of birth. This study assesses the relationship between use of digital prenatal services and VBAC. In this retrospective cohort study, we analyzed the use of digital prenatal services and mode of birth among users of an employer-sponsored digital women's and family digital health platform. All users had a prior cesarean birth. Users' self-reported data included demographics, medical history, and birth preferences. We used basic descriptive statistics and logistic regression models to assess the association between digital services utilization and VBAC, adjusting for key patient characteristics. Of 271 included users, 44 (16.2%) had a VBAC and 227 (83.8%) had a cesarean birth. Users of both groups were similar in age, race, and ethnicity. Fewer users in the VBAC group (5/44, 11.4%) as compared with the cesarean birth group (62/227, 27.3%) had a prepregnancy body mass index greater than or equal to 30 (P = 0.02). Likewise, more users in the VBAC group preferred vaginal birth (34/44, 77.3% vs 55/227, 24.2%; P < 0.01). In adjusted models, the services associated with VBAC were care advocate appointments (adjusted odds ratio [aOR], 7.67; 95% CI, 1.99-54.4), health care provider appointments (aOR, 1.12; 95% CI, 1.02-1.25), and resource reads (aOR, 1.05, 95% CI, 1.00-1.09). VBAC rates were higher for users who reported the digital health platform influenced aspects of their pregnancy and birth. Reducing cesarean birth rates is a national priority. Digital health services, particularly care coordination and education, are promising for accomplishing this goal through increasing rates of trial of labor after cesarean and subsequent VBAC rates.

Vaginal Birth after a Cesarean Section at Good Shepherd Mission Hospital at Tshikaji in Democratic Republic of the Congo (DRC)

Background: The success rate of vaginal birth after cesarean section with a single cesarean scar is greater than 50%, the lack of the information about the safety of vaginal birth after cesarean delivery pushes most of obstetricians to increase the num ber of cesarean sections following a previous cesarean section. Guidelines for Vaginal birth after cesarean (VBAC) indicate that TOLAC offers women with no contraindications and one previous transverse low-segment cesarean. The objective of the current study was to study the outcome of trial of labour after caesarean section (TOLAC), the indications for emergency repeat cesarean section and to determine the maternal and fetal prognosis in vaginal birth after caesarian section (VBAC) at Tshikaji Mission Hospital. Patients, Material and Methods: This is a retrospective study of the records of 126 women were selected to undergo the TOLAC in the department of gynecology and obstetrics at the Tshikaji Mission Hospital over the period from January 1st to December 31st, 2021. The data on demography, antenatal care, labour and delivery and outcomes were collected from the maternity unit of this hospital. The data were analyzed using SPSS version 2.0. Results: The TOLAC in 126 studied women. The course of work allowed vaginal delivery 107 parturient women, a success rate of successful VBAC of 85% after the TOLAC. The repeat emergency cesarean section was necessary for delivery in 15% of cases for failed TOLAC. There was no maternal mortality, but we recorded one fetal death or 0.8% of perinatal mortality, 2 cases of cicatricial dehiscence, the incidence of 1.6%. Maternal morbidity after delivery on cicatricial uterus was dominated by postpartum hemorrhages, with 19 cases or 15.1% of cases. Cervical dilatation of more than 3 cm at the time of admission, the parity more than 3 and were the significant factors in favor of a successful VBAC. Birth weight of more than 3500 g, fetal distress and malpresentation were associated with a lower success rate of VBAC. The TOLAC in selected cases has great importance in the present era of the rising rate of primary CS especially in rural areas. Conclusion: Pregnancy on a cicatricial uterus represents a high-risk pregnancy. Trial of VBAC in selected cases has great importance in the present era of the rising rate of primary CS especially in rural areas. There is a significantly high vaginal birth after caesarian section (VBAC) success rate among selected women undergoing trial of scar in Tshikaji Hospital. TOLAC remains the option for childbirth in low resource settings as Kasai region in DRC. Adequate patient education and counselling in addition to appropriate patient selection for TOLAC remain the cornerstone to achieving high VBAC success rate.

Trends in Attempted and Successful Trial of Labor After Cesarean Delivery in the United States From 2010 to 2020.

The vaginal birth after cesarean (VBAC) delivery rate was last reported as 13.8% in 2019. However, contemporary trends in attempted and successful trial of labor after cesarean (TOLAC) delivery among individuals with prior cesarean delivery have not been evaluated. We performed a repeated cross-sectional analysis of singleton, cephalic, term deliveries in individuals with a history of one or two cesarean deliveries in the National Vital Statistics System from 2010 to 2020. Temporal trends in attempted and successful TOLAC, as well as VBAC, were characterized using joinpoint regression. Overall, 4,277,800 deliveries were included. Attempted TOLAC increased from 15.3% in 2010 to 21.7% in 2020, with an annual percent increase (relative) of 4.25% (95% CI 2.9-5.6%). Successful TOLAC increased from 69.8% to 74.7%, with an annual percent change (relative) of 0.91% (95% CI 0.7-1.2%). The VBAC rate similarly increased such that, by 2020, it was 16.2%.

Racial Disparities in Respectful Maternity Care During Pregnancy and Birth After Cesarean in Rural United States

ObjectiveTo describe the experiences of pregnancy and birth after cesarean of women who live in rural areas of the United States, including access to vaginal birth after cesarean (VBAC), type of maternity care provider, travel times, autonomy in decision making, and respectful maternity care. DesignRetrospective observational study. SettingOnline questionnaire of women who gave birth in the United States. ParticipantsWomen (N = 1,711) with histories of cesarean and subsequent births within 5 years of participating. MethodsWe calculated descriptive and bivariate statistics by identified areas of residence and stratified measures of autonomy and respectful maternity care by self-identification as a member of a racialized group. We applied qualitative descriptive analysis to responses to an open-ended survey question. ResultsA total of 299 (17.5%) participants identified their areas of residence as rural. Similar percentages of rural and metropolitan participants were able to plan VBAC (p = .88). More rural participants than metropolitan participants reported travel times of more than 60 minutes to give birth (p < .001), and fewer had obstetricians (p = .002) or doulas (p = .03). Rural participants from racialized groups experienced significantly less respectful maternity care than White, non-Hispanic rural participants and all metropolitan participants (p = .04). Qualitative data illustrating the main findings are included. ConclusionsOur findings highlight challenges faced by rural residents accessing VBAC and help explain why rates of VBAC in rural areas remain low. We suggest a range of clinical and policy strategies to improve access to VBAC in rural areas and to improve the quality of maternity care for racialized women who live in rural areas.

Predicting vaginal birth after caesarean section: Validation of the Grobman model in a New Zealand population.

The decision regarding mode of birth following a primary caesarean section is important. Women may choose an elective repeat caesarean section or a trial of labour in an attempt to achieve a vaginal birth after caesarean (VBAC). The highest morbidity and mortality is associated with those who have an emergency caesarean section following a trial of labour. Therefore, the ability to accurately predict successful VBAC is important in antenatal counselling. To test the validity of the Grobman prediction nomogram in a New Zealand (NZ) population. A retrospective cohort study was performed of women carrying a singleton, cephalic pregnancy at term and who had one previous lower segment caesarean section in Northland, NZ. The probabilities of successful VBAC were calculated using the variables in the Grobman model and compared with observed VBAC rates using a calibration curve. The predictive ability of the model was assessed using area under the receiver operating characteristic curve (AUC). Of the 421 eligible women, 354 elected to undergo a trial of labour, of whom 69.5% had a successful VBAC. The AUC for the Grobman model was 0.72 (95% CI 0.67-0.78) with predicted and actual outcomes being similar when predicted success was over 50%. The predictive ability of the model appeared more accurate for Māori and Pacifika women compared to the NZ European population. The Grobman model predicts successful VBAC reasonably well in a NZ population and can be used as an antenatal counselling aid.

MFMU TOLAC Calculator: Does knowledge of a predicted success score increase VBAC rates?

The Maternal Fetal Medicine Units (MFMU) Network developed a calculator to determine a Trial of Labor after Cesarean (TOLAC) success score based on maternal age, BMI and OB history. Despite wide-spread adoption, it is unclear whether provider knowledge of a predicted score alters the likelihood of a successful vaginal birth after cesarean (VBAC). We aimed to determine whether provider knowledge of the MFMU calculated TOLAC score effects VBAC rates.

Recent Trends in Term Trial of Labor After Cesarean by Number of Prior Cesarean Deliveries

Cesarean delivery (CD) is a major source of maternal morbidity and repeat CD accounts for 40% of CD, but data on trial of labor after cesarean (TOLAC) and vaginal birth after cesarean (VBAC) are limited. The objective of this study was to report national rates of TOLAC and VBAC by number of prior cesareans.

Castor oil for labor initiation in women with a previous cesarean section: a double-blind randomized study

Objective: To evaluate the efficacy of castor oil in initiation of labor in women who had one previous cesarean section. This study was conducted as a trial to increase the rate of vaginal birth after cesarean (VBAC) and decrease the rate of elective repeated cesarean section (ERCS). Methods: A double-blinded randomized controlled study was conducted in an Egyptian University Hospital from July 2019 to July 2020. The participants were 70 pregnant women who had one previous cesarean section, singleton pregnancy in cephalic presentation, with a Bishop score ≤6 attempting to perform a trial of labor. Sixty mL castor oil was administered to group A and 60 mL sunflower oil was administered to group B (as a placebo) for initiation of labor at the start of week 39. Primary outcomes were the percentage of women entering the active phase of labor within 24 h after receiving castor oil or placebo and the number of successful VBAC deliveries. Results: Labor started in 16 patients (45.7%) within 24 h in the castor oil group and in 3 patients in the placebo group (8.5%), while the rate of successful VBAC was 65.7% (23 patients) in the castor oil group and 48.5% (17 patients) in the placebo group. Conclusion: Castor oil appears to be an effective, low-cost, and non-harmful method for the initiation of labor in patients with a previous cesarean section.

A Study of Feto-Maternal Outcome in Cases of Vaginal Birth after Cesarean SectionA Study of Feto-Maternal Outcome in Cases of Vaginal Birth after Cesarean Section

Introduction: Pregnancy with a previous cesarean section(CS) may lead to several concerning maternal, fetal, and neonatal complications in subsequent pregnancies such as placenta accreta and uterine rupture.Trial of labour after cesarean (TOLAC) and Vaginal Birth After Cesarean (VBAC) has a quantifiable effect on decreasing total cesarean deliveries. Aim: To assess maternal and fetal outcome of vaginal birth after one lower segment cesarean section in selected cases. Materials And Methods: Prospective observational study of maternal and fetal outcome included 100 ANC patients with singleton pregnancy of more than 34 weeks gestation and one previous lower transverse cesarean delivery admitted in SMIMER hospital between January 2018 to June 2019. Results: 57% patients had vaginal delivery without any assistance, while 18% patients required vacuum assistance and 25% patients required repeat LSCS after failure of TOLAC. Among successful VBAC none had any complications, while among repeated CS patients, 4% patients had PPH, 2%had intraoperative finding of uterine dehiscence and 1%had intraoperative finding of uterine scar rupture.67% had interval of ≤ 3 years between current and previous pregnancy. Bishop’s score of less than 8 resulted in 100% CS whereas Bishop’s score of more than 9 resulted in 100% VBAC.Among VBAC, 5.3% babies required NICU admission, while among repeated CS, 16% babies required NICU admission. Conclusion: This study has found a high success rate of VBAC (75%). Keywords: Vaginal birth after cesarean section; trial of labour after cesarean section.

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.

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)

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)

746 The effects of removing race from the VBAC calculator: implications for counseling

To explore the differences between actual vaginal birth after cesarean (VBAC) success rates and the predicted VBAC success scores when calculated both with and without race and ethnicity. A retrospective chart review of an ethnically diverse patient population with 302 women electing trial of labor after cesarean (TOLAC). The MFMU VBAC calculator was used to calculate a predicted VBAC score with and without race and ethnicity. Based on prior studies, a predicted success score of 60% or greater was defined as a favorable VBAC score. Predicted and actual rates of VBAC were then compared. Statistical analysis performed in SAS 9.4. There were no significant differences in VBAC rates when comparing non-Hispanic Black women, aOR 0.5 (95% CI 0.2, 1.28), and Hispanic women, aOR 0.9 (95% CI 0.34, 2.41), to non-Hispanic White women. However, when race and ethnicity were included in the VBAC calculator, non-Hispanic Black and Hispanic women were significantly less likely to have favorable VBAC scores compared to White women, aOR 0.26 (CI 0.1, 0.66) and aOR 0.24 (CI 0.09, 0.64), respectively. When race and ethnicity were excluded from the calculator, there was no longer a significant difference in the predicted VBAC success across racial groups, non-Hispanic Black aOR 1.29 (95% CI 0.49, 3.44); Hispanic aOR 1.71 (95% CI 0.6, 4.92). We found that with race and ethnicity included in the calculator, 33 Hispanic women (44.6%) who had a VBAC, would have been told they had an unfavorable score compared to only 7 women (9.5%) when race was excluded. Similarly, 29 non-Hispanic Black women (43.9%) who had a VBAC, would have been told they had an unfavorable score compared to only 8 women (12.1%) when race and ethnicity were excluded. The inclusion of race and ethnicity in the VBAC calculator underestimated the success rates of women of color and could lead to these women being discouraged from TOLAC when they would have been successful. Our findings support the removal of race from medical decision making.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

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.

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)