VBAC Attempts Research Articles

Is Incision to Delivery Time Associated With Poor Neonatal Neurological Outcomes in Women With Class 3 Obesity? [31L

INTRODUCTION: Morbid obesity has been associated with adverse neonatal outcome. We sought to determine factors associated with adverse outcome, specifically whether incision to delivery time (IDT) was an independent risk factor for poor neonatal outcome in a morbidly obese patient. METHODS: Secondary analysis of the MFMU Cesarean Registry. Inclusion criteria were singleton pregnancy, >37 weeks EGA and BMI >40 undergoing cesarean section. Patients were stratified into 2 groups: cesarean for fetal (fetal CS) and non-fetal (non-fetal CS) indications. The primary outcome was a neonatal composite of seizure, CPR <24 hrs, death, ventilatory support >2 d, HIE, pH <7.1 and APGAR 5 <5. Multivariate logistic regression was performed to assess impact of IDT and additional risk factors. RESULTS: The primary outcome was observed in 543 and 106 neonates (total n=6325) in the non-fetal CS and fetal CS subgroups respectively. Median IDT was 14.1 m for the non-fetal CS and 7.7 m for the fetal CS respectively. Women with poor neonatal outcome were more likely to be black race, affected by hypertensive diseases of pregnancy, higher BMI, have attempted labor, and have failed a VBAC attempt (Table 1). In the regression model, IDT>90th was not associated with adverse outcomes in the non-fetal CS group and was significantly associated with normal outcomes in the fetal CS group (Table 2). CONCLUSION: In the non-fetal CS subgroup, IDT >90th percentile was not associated with adverse outcomes. In the fetal CS subgroup, women with IDT >90th percentile were not associated with an increased risk of morbidity. Black race was associated with poor outcomes in both subgroups.

392: Comparison of performance of vaginal birth after cesarean prediction model “early in pregnancy” with VBAC prediction model “prior to VBAC attempt”.

392: Comparison of performance of vaginal birth after cesarean prediction model “early in pregnancy” with VBAC prediction model “prior to VBAC attempt”.

Provider Commitment Is Key for High Vaginal Birth After Cesarean Delivery Rate in a Community Hospital [274

INTRODUCTION: As a community hospital committed to vaginal birth after cesarean delivery (VBAC), we reviewed our experience from 2000 to 2013 to identify contributors to successful VBAC. Our health care providers were both midwives and physicians. METHODS: Using an electronic clinical database that served as a partial electronic medical record, we reviewed records from 2000 to 2013 for all women who had a prior cesarean delivery. We collected patient demographics, insurance, epidural use, and health care provider type. All labor trials were examined for details of labor management, indication for and dilation at cesarean delivery, and neonatal morbidities. Although we reviewed all VBACs in the final analysis, we excluded women who had had a prior vaginal birth. The analysis was then confined to women who had had one prior birth that was via cesarean section. RESULTS: A total of 1,788 women with a single prior birth that was a cesarean delivery were studied, among whom 617 had a VBAC attempt (34.5%); 431 VBAC attempts were successful (70%). Among 289 VBAC attempts among private patients (epidural rate of 73%), the success rate was 66%. For 328 MediCal public patients (epidural rate of 50%), the success rate was 73%. Neither maternal age at delivery nor maternal BMI prior to gestation influenced VBAC success rates. However, private patients were approximately 7 years older than the public patients (mean private age of 36 years old with a standard deviation of 4 years versus the mean public age of 29 years old with a standard deviation of 5 years). Private patients also had a lower pregestation BMI than the public patients (private BMI of 24 versus public BMI of 27 with a standard deviation of 5). Due to changes in county funding in 2011, a combined public and private foundation model was established and a hospitalist care model for labor and delivery was expanded. Although public patients remained primarily managed by midwives as they had been in the past, now private foundation patients had access to both the midwives and hospitalists that may be different from their prenatal doctor. All other variables remained the same, namely, in house 24/7 anesthesia and pediatrics along with in-house OB (as the hospitalist) and in-house midwife. As this collaborative model progressed from 2011 to 2013, we were able to see a reversal of decreasing VBAC rates combined with continued high VBAC success along with good maternal and neonatal safety profiles. Among private patients, the VBAC rate starting at 19% in 2010 (had been as low as 12% in 2007), ended up at a high of 33% in 2013. In addition, neonatal outcomes among VBAC attempt patients were excellent with a single uterine rupture (0.2%) and a 5-minute Apgar less than 7 rate of 0.4%, both unchanged from the earlier period. CONCLUSION: Despite calls for more VBACs, a 10% VBAC rate nationally has not budged much in the last 5 years. Within the same small community hospital (1500 births/year), among all health care provider groups, VBAC rates started high, then followed the descending national rates and then in 2011 reversed. This reversal was due to an increase in VBAC attempts and largely related to a new collaborative model in which private doctors allowed other providers to manage and deliver their patients. Those providers could be either the in-house midwife or the OB hospitalist. In addition, the VBAC success rate was uniformly high at 70%. Health care provider commitment is critical to achieving higher VBAC rates in hospitals that offer VBAC. In this setting, VBAC was quite safe.

Re: Predicting successful vaginal birth after Cesarean section using a model based on Cesarean scar features examined by transvaginal sonography. O. Naji, L. Wynants, A. Smith, Y. Abdallah, C. Stalder, A. Sayasneh, A. McIndoe, S. Ghaem-Maghami, S. Van Huf

Linked Comment: Ultrasound Obstet Gynecol 2013:41:672–678 In this issue of the Journal, Naji et al. suggest a prognostic model for the likelihood of successful VBAC, constructed using a single-center sample of 131 women with VBAC planned at ≥ 38 gestational weeks. The outcome measure for this model is successful vaginal delivery and the predictors comprised maternal age, prior successful VBAC, residual myometrial thickness (RMT) in the second trimester and change in RMT from the first to the second trimester (ΔRMT). The authors should be congratulated for having conducted a methodologically rigorous study using appropriate statistical analyses. However, the rationale for such a model and its construction is not obvious and several issues should be borne in mind when considering the take-home message(s) of this work. First, do we wish to predict the failure to deliver vaginally and the resulting morbidity of an emergency Cesarean section or the risk of acute uterine rupture and its undisputed morbidity and mortality for both the mother and newborn? The latter is quite rare and poorly reported in most studies, including the present one, in which uterine rupture was defined as a full-thickness separation of the uterine wall and overlying serosa observed at Cesarean section, regardless of the causal relationship of this finding with maternal and fetal distress. Naji et al. chose to predict VBAC, thereby questionably classifying emergency Cesarean section during labor as an adverse event, regardless of the cause. However, they cleverly investigated the impact of a physician or patient's level of tolerance to the risk of emergency Cesarean on the model-based decision using decision curves, suggesting overall superiority of a model-based decision with mode of delivery as the outcome of interest. Second, in routine obstetrics, a constant goal is to refine the appraisal of future risks. A model therefore aims to predict a complication that may occur, and the choice of covariates to predict this outcome is of crucial importance. In their article, Naji et al. suggest a model based upon first- and second-trimester measurements of RMT together with two simple demographic covariates as predictors for a successful VBAC. In their population, this model was strikingly discriminative, with an area under the model-associated receiver–operating characteristics curve of 0.96, indicating that one should be able to discriminate with very high confidence (i.e. with a very low false-positive rate) those patients who will eventually require a Cesarean section for any reason during labor. This result should be interpreted with caution, as it suggests that this set of covariates strongly determines the occurrence of any peripartum complication, such as arrested cervical dilatation and fetal distress. Moreover, in the final multivariable model, prior VBAC was found to be statistically non-significant, emphasizing the potential role of RMT as the sole determinant of successful VBAC. Although the quality of the scar tissue may be related to arrested dilatation and fetal distress, it cannot be expected that ultrasound scar characteristics in the first and second trimesters explain all possible complications that can occur during labor in VBAC attempts. Third, the interpretation and generalization of results does not depend solely on the choice of outcome, covariates and study population; it also depends on variations in local practice. For example, in the study of Naji et al., 17/121 (14%) women attempting VBAC were induced using prostaglandins, with a visible effect on the outcome, yielding 9/17 subsequent emergency Cesarean sections. Such practice is not universal and would be contraindicated in some centers. Conversely, as expected, successful VBAC was associated with spontaneous onset of labor. Similarly, breech presentation and low-lying placenta may be considered contraindications for VBAC, if not for vaginal birth altogether. Nonetheless, breech and placenta previa accounted for 10.7% of the Cesarean sections performed during labor in the present study. More subtle parameters, such as the opinion of the obstetrician regarding VBAC and elective repeat Cesarean section, are difficult to measure, but are likely to affect the results. These reasons make validation in external populations mandatory and might explain failure of the validation process if this were to occur. This work shows the potential impact on the outcome of VBAC of measurement of RMT by transvaginal ultrasound in the first and second trimesters. This finding adds to our understanding of the mechanisms that underlie obstetric complications in VBAC and, in the future, should help in refining the path of care of women with prior Cesarean section. However, as the authors themselves acknowledge, it would be inappropriate to implement this model in routine practice without further validation. Not only should the model itself be validated but also its impact on public health outcomes in large populations should be investigated in an evidence-based process. J. Stirnemann Obstetrics and Maternal Fetal Medicine, Hôpital Necker–Enfants Malades, AP-HP, Paris, France; Applied Mathematics, MAP5, UMR CNRS 8145 Université Paris Descartes, Paris, France (e-mail: j.stirnemann@gmail.com)

659: VBAC success in low risk women

Jodi Regan, Katherine Wolfe, Candice Snyder, Amy Thompson, Emily DeFranco University of Cincinnati College of Medicine, Obstetrics and Gynecology, Cincinnati, OH OBJECTIVE: The NIH Consensus Development Conference Statement from March of 2010 on Vaginal Birth after Cesarean identified several critical knowledge gaps in clinical decision making regarding trial of labor versus repeat cesarean in women with a prior cesarean delivery. One of the critical gaps identified was insufficient information regarding factors increasing VBAC success among low risk women. The aim of this study is to address this critical gap. STUDY DESIGN: We performed a population-based retrospective cohort study of all births in the state of Ohio in 2006 and 2007 to evaluate factors associated with an increased likelihood of successful VBAC in low risk women. We defined the low risk population as singleton gestations in women with BMI 30 without hypertension or diabetes who had one previous cesarean delivery and underwent a trial of labor with the current birth. We stratified factors into 4 groups: demographic, social, medical, and prenatal care, and compared them between low risk women with failed VBAC attempt vs those with successful VBAC. Multivariate logistic regression estimated the relative influence of each factor on successful VBAC. RESULTS: There were 291,782 births in Ohio during the time period. Of those, 186,719 were in low risk women. 13,639 women had one previous cesarean; 3,261 (23.9%) had a trial of labor after cesarean. Of those 2534 (77.7%) were successful in their VBAC attempt, whereas 727 (22.3%) were not. The following factors were found to be significantly associated with VBAC success in low risk women: prior vaginal delivery, delivery at term, pregnancy weight gain 30 lbs, Caucasian race, labor augmentation, limited prenatal care ( 5 visits), and midwife delivery attendant (see table). These factors were NOT associated with whether a low risk woman had a successful or failed VBAC attempt: maternal age, marital status, educational status, medical insurance type, cigarette use or birth weight. CONCLUSION: Low risk women with one prior cesarean can be counseled regarding increased likelihood of VBAC success in the presence of these demographic characteristics.

Vaginal Birth After Caesarean for Women With Three or More Prior Caesareans: Assessing Safety and Success

The rate of uterine rupture and other complications is relatively low in women with a history of 2 prior cesareans who attempt vaginal birth (VBAC). Outcome data for women who have had more than 2 previous cesareans are limited, largely because prior studies often combined women with a history of more than 2 cesareans into 1 group and also had small sample sizes. It is possible that the risk of morbidity among women with more than 2 prior cesareans who attempt VBAC may be less than presumed, especially in women with a high likelihood of success. The aim of this retrospective cohort study was to compare the rate of success and risk of maternal morbidity among women with a history of 3 or more prior cesareans, who attempt VBAC with that of women who had repeat cesarean after 1 or 2 prior cesareans. The study was performed at 17 centers in the Northeast United States between 1996 and 2000. The study population was 25,005 women with at least 1 prior cesarean delivery. Univariate analysis was performed, and stratified analyses were used to adjust for potential confounding variables. The primary study outcome measures were a composite of maternal morbidity, defined as the occurrence of any one of the following: symptomatic uterine rupture, bladder or bowel injury, or uterine artery laceration. Secondary outcomes included VBAC success, the individual components of the composite outcome, and the presence of transfusion and fever. Of the 25,005 women, 860 (3.4%) had 3 or more prior cesareans; 89 (10.3%) of these attempted VBAC, and 771 (89.7%) had an elective repeat cesarean. No cases of composite maternal morbidity were found among the 89 women who attempted VBAC. Univariate analysis showed that women who attempted VBAC after 3 or more prior cesareans had a similar likelihood of success as women who attempted VBAC after 1 prior cesarean (79.8% vs. 75.5%). After adjusting for previous vaginal delivery, induction use of oxytocin, and diabetes, the similarity remained; the adjusted odds ratio was 1.4, with a 95% confidence interval of 0.81 to 2.41, P = 0.22. These findings indicate that there is no higher risk of maternal morbidity or failed VBAC attempt among women who attempt VBAC after 3 or more prior cesarean deliveries compared with women who attempt VBAC after 1 prior cesarean, as well as those having had 2 prior cesareans. These data are consistent with other studies and suggest that the current recommendations for VBAC attempts in women with more than 1 prior cesarean should be re-evaluated.

White’s Classification of Maternal Diabetes and Vaginal Birth After Cesarean Delivery Success in Women Undergoing a Trial of Labor

To estimate the rate of vaginal birth after cesarean delivery (VBAC) success in diabetic women based on White's Classification. This is a secondary analysis of an observational study conducted at 19 medical centers of women attempting VBAC. Diabetic women with singleton gestations, one prior cesarean delivery, and cephalic presentation who underwent a trial of labor were included. Vaginal birth after cesarean delivery success rates and maternal and neonatal complications were compared based on White's Classification. Of 11,856 women who underwent trial of labor, 624 met all study criteria (class A1, 356; A2, 169; B, 70; C, 21; D/R/F, 8). Vaginal birth after cesarean delivery success in each group was: A1, 68.5% (95% confidence interval [CI] 63.4-73.3%); A2, 55% (95% CI 47.2-62.7%); B, 70% (95% CI 57.9-80.4%); C, 47.6% (95% CI 25.7-70.2%); and D/F/R, 12.5% (95% CI 0.3-52.7%). Maternal and neonatal complications were rare and not found to be different among groups. Our study provides estimates for VBAC success based on White's classification and indicates a relatively low rate of perinatal complications after VBAC attempt for diabetic women. III.

Racial Disparity in the Success and Complications of Vaginal Birth after Cesarean Delivery

Cahill, A. G.; Stamilio, D. M.; Odibo, A. O.; Peipert, J.; Stevens, E.; Macones, G. A. Author Information

Clinical Outcomes in VBAC Attempts: What to Say to Patients?

Clinical Outcomes in VBAC Attempts: What to Say to Patients?

Effect of gestational age at the prior cesarean delivery on maternal morbidity in subsequent VBAC attempt

The purpose of this study was to estimate the effect of gestational age at the time of prior cesarean on maternal morbidity in women attempting vaginal birth after cesarean delivery (VBAC). A retrospective cohort study of women attempting VBAC, comparing women with a prior cesarean delivery < or = 34 completed weeks to women with a prior cesarean delivery > 34 weeks. The primary outcome was maternal morbidity, including uterine rupture. Univariable, stratified, and multivariable analyses were used to estimate the effect of a prior cesarean performed at < or = 34 weeks on maternal morbidities. Of 19,474 women with 1 prior cesarean, 12,535 attempted VBAC and 508 of those had a previous cesarean < or = 34 weeks. Study groups had similar risks of uterine rupture (adjusted OR [AOR], 1.5; 95% CI, 0.7-3.5; P = .32) and composite morbidity (AOR, 0.9; 95% CI, 0.5-1.8; P = .81). Prior cesarean delivery at < or = 34 weeks' gestation does not appear to increase the risk of maternal morbidity in a subsequent VBAC attempt.

Racial Disparity in the Success and Complications of Vaginal Birth After Cesarean Delivery

To determine if race is associated with election to attempt vaginal birth after cesarean delivery (VBAC), VBAC success, and maternal morbidities associated with VBAC. A retrospective, multi-center cohort study was conducted of women with a history of at least one prior cesarean delivery. Data were obtained on maternal demographics, medical history, antepartum and intrapartum course, delivery mode, and maternal outcomes. This analysis examines the association between race and the choice to have VBAC and compares the rates of VBAC success and maternal morbidity, including uterine rupture, and a composite morbidity outcome (uterine rupture, bladder and bowel injury, and artery laceration) across race groups. Race was determined by patient self-report. Univariable and multivariable analyses were performed to assess the independent association of race and clinical outcomes. The cohort included 25,005 patients with at least one prior cesarean delivery. In unadjusted and multivariable analysis, black patients were more likely to undertake a trial of labor than patients of other races, and slightly more likely to experience a failure of VBAC attempt. However, black women who attempt VBAC are 40% less likely to sustain a uterine rupture (0.6% compared with 1.1%) than other racial groups, even after adjusting for relevant potentially confounding variables. Despite increased rates of VBAC attempt and VBAC failure among black women as compared with other racial groups, black women are significantly less likely to experience a uterine rupture. It is unclear whether this discrepancy in magnitudes of risks and benefits across race associated with VBAC trials is attributable to selection bias or inherent racial differences.

Labor Outcomes With Increasing Number of Prior Vaginal Births After Cesarean Delivery

To estimate the success rates and risks of an attempted vaginal birth after cesarean delivery (VBAC) according to the number of prior successful VBACs. From a prospective multicenter registry collected at 19 clinical centers from 1999 to 2002, we selected women with one or more prior low transverse cesarean deliveries who attempted a VBAC in the current pregnancy. Outcomes were compared according to the number of prior VBAC attempts subsequent to the last cesarean delivery. Among 13,532 women meeting eligibility criteria, VBAC success increased with increasing number of prior VBACs: 63.3%, 87.6%, 90.9%, 90.6%, and 91.6% for those with 0, 1, 2, 3, and 4 or more prior VBACs, respectively (P<.001). The rate of uterine rupture decreased after the first successful VBAC and did not increase thereafter: 0.87%, 0.45%, 0.38%, 0.54%, 0.52% (P=.03). The risk of uterine dehiscence and other peripartum complications also declined statistically after the first successful VBAC. No increase in neonatal morbidities was seen with increasing VBAC number thereafter. Women with prior successful VBAC attempts are at low risk for maternal and neonatal complications during subsequent VBAC attempts. An increasing number of prior VBACs is associated with a greater probability of VBAC success, as well as a lower risk of uterine rupture and perinatal complications in the current pregnancy. II.

Does a maximum dose of oxytocin affect risk for uterine rupture in candidates for vaginal birth after cesarean delivery?

The purpose of this study was to determine whether the maximum dose of oxytocin impacts the risk of uterine rupture in women who attempt vaginal birth after cesarean delivery (VBAC). We conducted a retrospective, multicenter cohort study of women with a history of cesarean delivery. We compared uterine rupture rates between VBAC candidates that did and did not receive oxytocin, analyzing the association between maximum dose of oxytocin and uterine rupture. Bivariate and multivariate analyses were performed. Of the 13,523 patients who elected a VBAC trial, 128 women experienced a uterine rupture; 80 of these ruptures were in women who received oxytocin (62.5%). There was evidence of "dose response" for maximum oxytocin amount and uterine rupture, with a uterine rupture rate of 2.07% (adjusted odds ratio, 2.98; 95% CI 1.51-5.90) at the highest dosages. In VBAC attempts, a dose-response relationship of maximum oxytocin and uterine rupture exists. These results provide evidence for vigilance when higher doses of oxytocin are given to patients who attempt VBAC.

Vaginal birth after caesarean delivery: does maternal age affect safety and success?

To estimate maternal age effects on the rates of vaginal birth after caesarean delivery (VBAC), the related maternal complications and patient election to attempt VBAC, we conducted a secondary analysis of a retrospective cohort study of women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. We used bivariable and multivariable analyses to assess the association between maternal age and the study outcomes. A total of 25 005 patients were included, of whom 13 706 (54.81%) elected to attempt VBAC. After controlling for several confounding variables, using ages 21-34 years as the referent group, women aged 15-20 years were 27% less likely to have a failed VBAC attempt (OR = 0.73 [0.62, 0.87], P < 0.001). Analysing maternal age as a dichotomous variable, women who were of advanced maternal age (>or=35 years) were more likely to experience an unsuccessful trial of labour (OR = 1.14 [1.03, 1.25], P = 0.009). In addition, women >or=35 years of age had 39% more risk of experiencing one of the VBAC-related operative complications (OR = 1.39 [1.02, 1.89], P = 0.039). As women increase in age, they are less likely to attempt VBAC and more likely to have an unsuccessful labour trial. While teenage patients do not appear to be at increased risk for VBAC-related complications, patients of advanced maternal age do show an increase in composite VBAC-related operative complication rates.

The MFMU cesarean registry: Changing patterns of VBAC attempts and success rates

The MFMU cesarean registry: Changing patterns of VBAC attempts and success rates

Obstetric Anesthesia Workforce Survey

Obstetric Anesthesia Workforce Survey

Obstetric outcomes in women with two prior cesarean deliveries: Is vaginal birth after cesarean delivery a viable option?

This study was undertaken to compare clinical outcomes in women with 1 versus 2 prior cesarean deliveries who attempt vaginal birth after cesarean delivery (VBAC) and also to compare clinical outcomes of women with 2 prior cesarean deliveries who attempt VBAC or opt for a repeat cesarean delivery. We performed a secondary analysis of a retrospective cohort study, in which the medical records of more than 25,000 women with a prior cesarean delivery from 16 community and tertiary care hospitals were reviewed by trained nurse abstractors. Information on demographics, obstetric history, medical and social history, and the outcomes of the index pregnancy was obtained. Comparisons of obstetric outcomes were made between women with 1 versus 2 prior cesarean deliveries, and also between women with 2 prior cesarean deliveries who opt for VBAC attempt versus elective repeat cesarean delivery. Both bivariate and multivariate techniques were used for these comparisons. The records of 20,175 women with one previous cesarean section and 3,970 with 2 prior cesarean sections were reviewed. The rate of VBAC success was similar in women with a single prior cesarean delivery (75.5%) compared with those with 2 prior cesarean deliveries (74.6%), though the odds of major morbidity were higher in those with 2 prior cesarean deliveries (adjusted odd ratio[OR] = 1.61 95% CI 1.11-2.33). Among women with 2 prior cesarean deliveries, those who opt for a VBAC attempt had higher odds of major complications compared with those who opt for elective repeat cesarean delivery (adjusted OR = 2.26, 95% CI 1.17-4.37). The likelihood of major complications is higher with a VBAC attempt in women with 2 prior cesarean deliveries compared with those with a single prior cesarean delivery. In women with 2 prior cesarean deliveries, while major complications are increased in those who attempt VBAC relative to elective repeat cesarean delivery, the absolute risk of major complications remains low.

The MFMU cesaraean section registry: Maternal morbidity associated with multiple repeat cesarean delivery

36 37 THE MFMU CESARAEAN SECTION REGISTRY: MATERNAL MORBIDITY ASSOCIATED WITH MULTIPLE REPEAT CESAREAN DELIVERY ROBERT M. SILVER, MFMU Network, NICHD, Bethesda, Maryland OBJECTIVE: There has been a substantial increase in the rate of cesarean delivery (CD) over the past decade, including primary elective cases. In part, this has been justified by the relative safety of CD in modern obstetrics. Although multiple repeat CD often are associated with serious morbidity they account for only a portion of abdominal deliveries and are overlooked when evaluating morbidity. Our objective was to estimate whether morbidity is higher with increasing numbers of CD. STUDY DESIGN: Prospective observational cohort of 30,132 women with CD without labor in 19 academic centers over 4 years (1999–2002). RESULTS: The risk of accreta, accreta with previa, and hysterectomy increased with increasing numbers of CD (Table; all P ! .001), as did the risk of blood transfusion of 4 or more units (P ! .001). In the 143 women with accreta, the risk of cystotomy, but not other co-morbidity, increased with increasing number of CD (P ! .001). CONCLUSION: Serious maternal morbidity increases with increasing numbers of CD. Thus, the number of intended pregnancies should be factored into consideration of elective cesarean or VBAC attempts. This large series confirms the high risk of accreta in women with previa and 2 or more prior CD. However, the risk of accreta in women with previa and 1 prior CD is less than previously reported. () accretas in women with previas; Hyst – hysterectomy).

Vaginal birth after Cesarean delivery: predicting success, risks of failure

Objectives: To identify predictors of successful trial of labor in women after one low transverse Cesarean delivery and no prior deliveries, and to assess perinatal morbidity associated with a failed vaginal birth after Cesarean delivery (VBAC).Methods: Retrospective chart review of women with one low transverse Cesarean delivery in their first pregnancy who delivered their next pregnancy at our institution. Clinical characteristics and intrapartum data were reviewed to identify predictors of successful VBAC. Perinatal outcomes were reviewed to assess morbidity associated with VBAC attempt and failed VBAC.Results: Of 768 women studied, 522 (68%) attempted VBAC and 344 (66%) of these were successful. Uterine rupture occurred in 0.8% of the VBAC group. On initial examination, women with cervical dilation > 1 cm, effacement > 50% and station lower than – 1 were more likely to deliver vaginally. Women with successful VBAC had more spontaneous labor (85.2 vs. 76.4%, p = 0.02) and less oxytocin use (49.7 vs. 70.8%, p < 0.0001). There were no differences in outcomes between failed and successful VBAC, except more frequent 1-min Apgar scores < 5 (10.1 vs. 4.1%, p = 0.01) and increased endometritis (9.6 vs. 2%, p = 0.0002) with failed VBAC. Compared with elective repeat Cesarean delivery, VBAC attempt was associated with amnionitis (5.9 vs. 0%, p < 0.0001) and low 1- and 5-min Apgar scores (6.1 vs. 2.4%, p = 0.03 and 2.3 vs. 0%, p = 0.01, respectively), but not endometritis, admission to a neonatal intensive care unit (NICU), ventilation, intraventricular hemorrhage (IVH) or seizures. Failed VBAC had more amnionitis (7.3 vs. 0%, p < 0.0001), postpartum fever (11.2 vs. 2.4%, p = 0.0003) and endometritis (9.6 vs. 2.0, p = 0.0007) than elective repeat Cesarean delivery and was associated with low 1- and 5-min Apgar scores (10.1 vs. 2.4%, p < 0.001 and 2.8 vs. 0%, p = 0.01, respectively), but not NICU admission, ventilation, IVH or seizures.Conclusions: Favorable initial pelvic examination, spontaneous labor and a lack of oxytocin use are associated with successful VBAC in women with a single prior low transverse Cesarean delivery and no prior vaginal deliveries. While attempted VBAC and failed VBAC have more maternal infectious morbidity and lower Apgar scores, infant outcomes are similar to those of elective repeat Cesarean delivery.

Risk factors for major maternal morbidity in VBAC attempts

Risk factors for major maternal morbidity in VBAC attempts