The critical need for academic health centers to assess the training, support, and career development requirements of clinical research coordinators: recommendations from the Clinical and Translational Science Award Research Coordinator Taskforce.

Clinical Research Coordinators (CRCs) are a vital component of the clinical research enterprise providing a pivotal role in human subject protection through the numerous activities and responsibilities assigned to them. In 2006, the National Institutes of Health's National Center for Research resources (NCRR) implemented the Clinical and Translational Science Awards program (CTSA) to advance biomedical research. As a part of this endeavor, many workgroups were formed among the Consortium to support translational research. The Research Coordinator Taskforce was created as part of the Regulatory Knowledge group of the Clinical Research Innovation Key Function Committee, and focuses on enhancing CTSA capabilities to provide support and training for CRCs. In the spring of 2008, this taskforce conducted two surveys of the then 24 CTSA Consortium members to better understand the current expectations and responsibilities of research coordinators in addition to the mechanism for providing education, training, and support in order for CRCs to successfully meet the study responsibilities placed upon them. The results of these surveys are summarized in this article and provide context to the recommendations of the Research Coordinator Taskforce for institutional considerations, approaches, and best practices for providing education, training, and support the expanding role of CRCs in fulfilling their responsibilities delegated to them by investigators.

Racial disparity in the success and complications of vaginal birth after cesarean delivery.

OBJECTIVE: To determine if race is associated with election to attempt vaginal birth after cesarean delivery (VBAC), VBAC success, and maternal morbidities associated with VBAC. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Minor trauma in pregnancy--is the evaluation unwarranted?

OBJECTIVE: The purpose of this study was to examine the rate of and risks for abruption and adverse pregnancy outcome after minor trauma in pregnancy. STUDY DESIGN: This is a 3-year prospective cohort study of patients after noncatastrophic trauma. Data collected included maternal demographics and history, trauma mechanism, and pregnancy outcome. Examination, lab tests including Kleihauer-Betke (KB), and a minimum of 4 hours of fetal monitoring were performed. The primary outcomes were placental abruption and a composite pregnancy morbidity outcome. Univariate and bivariate analysis were performed. RESULTS: Of the 317 patients evaluated for minor trauma, 9 had a positive KB test (2.8%). Delivery information was available on 256 (81%) patients, and there was 1 placental abruption. The 49 cases (19.4%) of composite outcome could not be predicted. CONCLUSION: Perhaps it is time to reevaluate the extensive evaluations often done after minor trauma in pregnancy, particularly because none of the commonly used objective measures are predictive of adverse outcomes.

Short interpregnancy interval: risk of uterine rupture and complications of vaginal birth after cesarean delivery.

OBJECTIVE: To investigate whether short or long interpregnancy interval is associated with uterine rupture and other major maternal morbidities in women who attempt vaginal birth after cesarean delivery (VBAC). METHODS: We performed a secondary analysis of a U.S. multi-center, record-based, retrospective cohort study of 13,331 pregnant women, identified by a validated International Classification of Disease, 9th Revision, code search, with at least one prior cesarean delivery, who attempted VBAC between 1995 and 2000. We performed univariable and multivariable logistic regression analyses to evaluate the association between long or short interpregnancy interval and three maternal outcomes: 1) uterine rupture, 2) composite major morbidity (including rupture, bladder or bowel injury, and uterine artery laceration), and 3) blood transfusion. We evaluated short interpregnancy interval with cutoffs at less than 6, less than 12, and less than 18 months between prior delivery and conception and defined long interval as 60 months or more. RESULTS: A total of 128 cases (0.9%) of uterine rupture occurred, and 286 (2.2%), 1,109 (8.3%), 1,741 (13.1%), and 2,631 (19.7%) women had interpregnancy intervals of less than 6, 6-11, 12-17, and 60 months or more, respectively. An interval less than 6 months was associated with increased risk of uterine rupture (adjusted odds ratio [aOR] 2.66, 95% confidence interval [CI] 1.21-5.82), major morbidity (aOR 1.95, 95% CI 1.04-3.65), and blood transfusion (aOR 3.14, 95% CI 1.42-6.95). Long interpregnancy interval was not associated with an increase in major morbidity. CONCLUSION: Short interpregnancy interval increases risk for uterine rupture and other major morbidities twofold to threefold in VBAC candidates. LEVEL OF EVIDENCE: II.

Do vaginal birth after cesarean outcomes differ based on hospital setting?

OBJECTIVE: The objective of the study was to test the null hypothesis that outcomes of vaginal birth after cesarean (VBAC) do not differ on the basis of the hospital setting. STUDY DESIGN: The study was a retrospective cohort study of women who were offered VBAC in 17 hospitals from 1996 to 2000. VBAC attempts occurring in hospitals with and without obstetrics-gynecology residency programs were compared, as were outcomes from university and community hospitals. Bivariate and multivariate logistic regression analyses assessed the association between hospital setting and VBAC outcomes. RESULTS: Of 25,065 women with 1 or more prior cesareans, the VBAC attempt rate was 56.1% at hospitals with obstetrics-gynecology residencies, 51.3% at hospitals without obstetrics-gynecology residencies, 61% at university hospitals, and 50.4% at community hospitals. The occurrence of failed VBAC, blood transfusion, or composite adverse outcome did not differ by hospital setting. There was a significant increase in the uterine rupture rate at community (1.2%) vs university hospitals (0.6%), but the absolute risk remained low. CONCLUSION: The rate of VBAC-associated complications is low, independent of hospital setting.

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

OBJECTIVE: 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). STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.

Predicting placental abruption and previa in women with a previous cesarean delivery.

The purpose of this study was to determine if placental abruption or previa in women with a history of a prior cesarean delivery (CD) can be predicted. A retrospective cohort study of pregnant women with previous CD was conducted in 17 centers between 1996 and 2000. Women developing placenta previa or abruption in the subsequent pregnancy were compared with those without these complications. Bivariate and multivariable techniques were used to develop predictive models for placenta previa or abruption. The area under the receiver-operator characteristic curves, sensitivity, specificity, and accuracy of the models were compared. Among 25,076 women with prior CD, there were 361 (15 per 1000 births) with placenta previa and 309 (13 per 1000 births) with abruption. The significant risk factors for these complications include advanced maternal age, Asian race, increased parity, illicit drug use, history of spontaneous abortion, and three or more prior cesarean deliveries. Prediction models for abruption and previa had poor sensitivity (12% and 13% for abruption and previa, respectively). In women with at least one prior cesarean delivery, the risk factors for placental previa and abruption can be identified. However, prediction models combining these risk factors were too inefficient to be useful.

Predicting failure of a vaginal birth attempt after cesarean delivery.

OBJECTIVE: To identify a group of clinical factors that could be used to accurately predict failure in women attempting vaginal birth after cesarean (VBAC). METHODS: We conducted a planned secondary analysis of a retrospective cohort study of women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. We collected information about maternal history and outcomes of the index pregnancy. We used univariable and multivariable statistical methods to develop a multivariable prediction model for the outcome of VBAC failure. RESULTS: A total of 13,706 patients attempted VBAC, with a failure rate of 24.5%. Six variables were significantly associated with VBAC failure in our final logistic regression model: gestational age at delivery, maternal age, maternal race, labor type (spontaneous, augmented, or induced), history of vaginal delivery, and cephalopelvic disproportion or failed induction (combined variable) as prior cesarean indication. The area under the receiver operating characteristics curve is 0.717. To achieve a sensitivity of approximately 75%, a false-positive rate of approximately 40% would result. CONCLUSION: Our results indicate that significant clinical variables (prelabor and labor) cannot reliably predict VBAC failure. LEVEL OF EVIDENCE: II.

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.

Can uterine rupture in patients attempting vaginal birth after cesarean delivery be predicted?

OBJECTIVE: This study was undertaken to use multivariable methods to develop clinical predictive models for the occurrence of uterine rupture by using both antepartum and early intrapartum factors. STUDY DESIGN: This was a planned secondary analysis from a multicenter case-control study of uterine rupture among women attempting vaginal birth after cesarean (VBAC) delivery. Multivariable methods were used to develop 2 separate clinical predictive indices--one that used only prelabor factors and the other that used both prelabor and early labor factors. These indices were also assessed with the use of Receiver operating characteristic curves. RESULTS: We identified 134 cases of uterine rupture and 665 noncases. No single individual factor is sufficiently sensitive or specific for clinical prediction of uterine rupture. Likewise, the 2 clinical predictive indices were neither sufficiently sensitive nor specific for clinical use (receiver operating characteristic curve [area under the curve] 0.67 and 0.70, respectively). CONCLUSION: Uterine rupture cannot be predicted with either individual or combinations of clinical factors. This has important clinical and medical-legal implications.

Is vaginal birth after cesarean (VBAC) or elective repeat cesarean safer in women with a prior vaginal delivery?

OBJECTIVE: This study was undertaken to determine whether vaginal birth after cesarean (VBAC) or elective repeat cesarean delivery is safer overall for a woman with a prior vaginal delivery. STUDY DESIGN: This retrospective cohort study of pregnant women from 1996 to 2000 who had a prior cesarean delivery, was conducted in 17 centers. Trained nurses extracted historical and maternal outcome data on subjects by using standardized tools. This planned secondary analysis examined the subcohort that had also previously undergone a vaginal delivery, comparing those who underwent a VBAC trial with those who elected to have a repeat cesarean delivery. Outcomes included uterine rupture, bladder injury, fever, transfusion and a composite (uterine rupture, bladder injury, and artery laceration). We performed bivariate and multivariable analyses. RESULTS: Of 6619 patients with a prior cesarean delivery who had also had a prior vaginal delivery, 5041 patients attempted a VBAC delivery and 1578 had an elective cesarean delivery. Although there was no significant difference in uterine rupture or bladder injury between the two groups, women who underwent a VBAC attempt were less likely to experience the composite adverse maternal outcome, have a fever, or require a transfusion. CONCLUSION: Among VBAC candidates who have had a prior vaginal delivery, those who attempt a VBAC trial have decreased risk for overall major maternal morbidities, as well as maternal fever and transfusion requirement compared with women who elect repeat cesarean delivery. Physicians should make this more favorable benefit-risk ratio explicit when counseling this patient subpopulation on a trial of labor.

Safety and success of vaginal birth after cesarean delivery in patients with preeclampsia.

The objective of this study was to determine if preeclampsia (PRE) or gestational hypertension (GH) affects the rate of success of vaginal birth after cesarean delivery (VBAC), VBAC-related complications, or patient election to attempt VBAC. We performed a retrospective cohort study of all women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. Demographic, medical, and obstetric history, complications, treatment, and index pregnancy outcome information was collected on all patients in the database. Bivariate analysis and multivariable logistic regression were used to assess the independent association between GH and PRE and the rate of success of VBAC, VBAC-related complications, or patient election to attempt VBAC. A total of 25,005 patients were registered in the database. 13,706 (54.81%) attempted VBAC and 11,299 (45.19%) elected repeat cesarean delivery. After adjusting for confounding variables using multivariable logistic regression, patients with PRE were more likely to fail VBAC (relative risk [RR], 1.56; 95% CI, 1.22 to 2.00). Patients with GH were less likely to attempt VBAC (RR, 0.39; 95% CI, 0.34 to 0.46). A total of 304 (1.46%) patients had a uterine rupture. The VBAC group had a rupture rate of 0.93% and the elective cesarean group had a rupture rate of 0.04%. There was no difference in uterine rupture rates between the cohorts. Patients with gestational hypertension were less likely to attempt a VBAC. Patients with PRE, if they attempted a VBAC trial, had a higher VBAC failure rate. Patients with PRE or GH do not have increased uterine rupture rates. These findings can be used to improve mode of delivery counseling for VBAC candidate patients with preeclampsia.

Maternal complications with vaginal birth after cesarean delivery: a multicenter study.

OBJECTIVE: This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings. STUDY DESIGN: We performed a case-control study nested within a cohort of women who have had a prior cesarean to determine the incidence and risk factors for uterine rupture in women attempting VBAC. RESULTS: The incidence rate of uterine rupture in those who attempt VBAC was 9.8 per 1000. A prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio [OR] = 0.40, 95% CI 0.20-0.81). Although prostaglandins alone were not associated with uterine rupture, sequential use of prostaglandin and pitocin was associated with uterine rupture (adjusted OR = 3.07, 95% CI 0.98-9.88). CONCLUSION: Women with a prior cesarean should be offered VBAC, and women with a prior cesarean and prior vaginal delivery should be encouraged to VBAC. Although other studies have suggested that prostaglandins should be avoided, we suggest that inductions requiring sequential agents be avoided.

Safety and efficacy of vaginal birth after cesarean attempts at or beyond 40 weeks of gestation.

OBJECTIVE: To compare rates of vaginal birth after cesarean (VBAC) failure and major complications in women attempting VBAC before and after the estimated date of delivery (EDD) METHODS: This was a 5-year retrospective cohort study in 17 university and community hospitals of women with at least 1 prior cesarean delivery. Women who attempted VBAC before the EDD were compared with those at or beyond 40 weeks of gestation. Logistic regression analyses were performed to assess the relationship between delivery beyond the EDD and VBAC failure or complication rate. RESULTS: A total of 11,587 women in the cohort attempted VBAC. Women past 40 weeks of gestation were more likely to have a failed VBAC. After controlling for confounders, the increased risk of a failed VBAC beyond 40 weeks remained significant (31.3% compared with 22.2%, odds ratio 1.36, 95% confidence interval 1.24-1.50). The risk of uterine rupture (1.1% compared with 1.0%) or overall morbidity (2.7% compared with 2.1%) was not significantly increased in the women attempting VBAC beyond the EDD. When the cohort was defined as 41 weeks or more of gestation, the risk of a failed VBAC was again significantly increased (35.4% compared with 24.3%, odds ratio 1.35, 95% confidence interval 1.20-1.53), but the risk of uterine rupture or overall morbidity was not increased. CONCLUSION: Women beyond 40 weeks of gestation can safely attempt VBAC, although the risk of VBAC failure is increased.

Vaginal birth after cesarean (VBAC) attempt in twin pregnancies: is it safe?

OBJECTIVE: The purpose of this study was to compare the rate of vaginal birth after cesarean (VBAC) attempt, VBAC failure, and major maternal adverse outcomes in women with a previous cesarean with twin or singleton pregnancies. STUDY DESIGN: This was a multicenter retrospective cohort study between the years 1996 and 2000. Subjects were identified by ICD-9 code. Trained research nurses collected medical record data on the outcome of VBAC attempts, and clinical outcomes, including uterine rupture and major operative injuries. We used bivariate and multivariable techniques to assess the association between twins and the outcomes. RESULTS: Of 25,005 patients with at least 1 previous cesarean, there were 535 twin pregnancies and 24,307 singleton pregnancies. Compared with patients with singleton gestations, patients with twins were less likely to attempt a VBAC (adjusted odds ratio [AOR] 0.3, 95% CI 0.2-0.4), but no more likely to have a VBAC failure (AOR 1.1, 95% CI 0.8-1.6), a uterine rupture (AOR 1.2, 95% CI 0.3-4.6), or a major maternal morbidity (AOR 1.6, 95% CI 0.7-3.7). CONCLUSION: Women with twin gestations are less likely to attempt a VBAC, but they are no more likely to fail a VBAC trial or experience a major morbid event compared with women with singleton gestations.

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

OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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). CONCLUSION: 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 effect of prematurity on vaginal birth after cesarean delivery: success and maternal morbidity.

OBJECTIVE: We sought to compare vaginal birth after cesarean (VBAC) success and uterine rupture rates between preterm and term gestations in women with a history of one prior cesarean delivery. Our hypothesis was that preterm women undergoing VBAC were more likely to be successful and have a lower rate of complications than term women undergoing VBAC. METHODS: We reviewed medical records of women with a history of a cesarean delivery who either attempted a VBAC or underwent a repeat cesarean delivery from 1995 through 2000 in 17 community and university hospitals. We collected information on demographics, medical and obstetric history, complications, and outcome of the index pregnancy. The primary analysis was limited to women with singleton gestations and one prior cesarean delivery. Statistical analysis consisted of bivariate and multivariable techniques. RESULTS: Among the 20,156 patients with one prior cesarean delivery, 12,463 (61%) attempted a VBAC. Mean gestational ages for the term and preterm women were 39.2 weeks and 33.9 weeks of gestation, respectively. The VBAC success rates for the term and preterm groups were 74% and 82%, respectively (P < .001). Multivariable analysis showed that the VBAC success was higher (adjusted odds ratio 1.54, 95% confidence interval 1.27-1.86) in preterm gestations. A decreased risk of rupture among preterm gestations was suggested in these results (adjusted odds ratio 0.28, 95% confidence interval 0.07-1.17; P = .08). CONCLUSION: Preterm patients undergoing a VBAC have higher success rates when compared with term patients undergoing a VBAC. Preterm patients undergoing VBAC may have lower uterine rupture rates.

Diet-controlled gestational diabetes mellitus does not influence the success rates for vaginal birth after cesarean delivery.

OBJECTIVE: We sought to determine whether women with diet-controlled gestational diabetes mellitus who attempt vaginal birth after cesarean delivery are at increased risk of failure, when compared with their non-diabetic counterparts. STUDY DESIGN: We identified 13,396 women who attempted vaginal birth after cesarean delivery among 25,079 pregnant women with a previous cesarean delivery who were delivered between 1995 and 1999 at 16 community and university hospitals. Analysis was limited to 9437 women without diabetes mellitus and 423 women with diet-controlled diabetes mellitus who attempted vaginal birth after cesarean delivery with a singleton gestation and 1 previous low-flap cesarean delivery. Data that were collected by trained abstractors, included demographics, medical history, and both pregnancy and neonatal outcomes. Multivariable logistic regression analysis was performed to determine an adjusted odds ratio for vaginal birth after cesarean delivery success among women with diet-controlled gestational diabetes compared with women with no diabetes mellitus. We controlled for birth weight, maternal age, race, tobacco, chronic hypertension, hospital settings, labor management, and obstetric history. RESULTS: Forty-nine percent of the women with gestational diabetes mellitus and 67% of the women with no diabetes mellitus attempted vaginal birth after cesarean delivery. The success rate for attempted vaginal birth after cesarean delivery among gestational diabetic women was 70%, compared with 74% for non-diabetic women. We found that gestational diabetes mellitus is not an independent risk factor for vaginal birth after cesarean delivery failure. The relative risk for vaginal birth after cesarean delivery success in women with gestational diabetes mellitus compared with women without gestational diabetes mellitus was 0.94 (95% CI, 0.87-1.00). After an adjustment was made for confounding, the odds ratio for success with gestational diabetes mellitus was 0.87 (95% CI, 0.68-1.10). CONCLUSION: Women with diet-controlled gestational diabetes mellitus who were carrying singleton fetuses who had no more than 1 previous low flap cesarean delivery should be counseled that their disease does not decrease their chances for a successful vaginal birth after cesarean delivery. Among diet-controlled diabetic women, the overall success rate for vaginal birth after cesarean delivery remains acceptable, and attempted vaginal birth after cesarean delivery should not be discouraged solely on the basis of gestational diabetes mellitus.

Impact of sociodemographic and hospital factors on attempts at vaginal birth after cesarean delivery.

OBJECTIVE: To estimate the clinical and nonclinical factors associated with whether a patient attempts a trial of labor after previous cesarean delivery or elects to have a repeat cesarean delivery. METHODS: We conducted a retrospective, cohort study comparing all women with previous low transverse cesarean delivery who attempted a trial of labor with those who elected to have a repeat cesarean delivery. Data from 17 hospital sites for the period 1995-1998 were included, for a total of 15,172 patients. Bivariate, site-adjusted, and multivariable logistic regression analyses were used. RESULTS: Odds of trial of labor by hospital were not uniform in the unadjusted or adjusted analyses. The odds of trial of labor decreased significantly with increasing age, gravidity, and number of previous cesarean deliveries. Medicaid patients had higher odds of trial of labor than did privately insured patients (odds ratio [OR] 1.37 [95% confidence interval (CI) 1.20, 1.55]). Patients with nonrecurrent indication for previous cesarean delivery had generally higher odds of trial of labor than did those with a recurrent indication. Black women were more likely to attempt trial of labor than were white women (OR 2.17 [95% CI 1.83, 2.56] for those with a nonrecurrent indication). CONCLUSION: Clinical and nonclinical factors influence rates of attempted vaginal birth after cesarean delivery.

The effect of birth weight on vaginal birth after cesarean delivery success rates.

OBJECTIVE: The purpose of this study was to evaluate the effect of increasing birth weight on the success rates for a trial of labor in women with one previous cesarean delivery. STUDY DESIGN: To evaluate the effect of increasing birth weight for women who undergo a trial of labor, the medical records of women who had attempted a vaginal birth after cesarean delivery (VBAC) from 1995 through 1999 in 16 community and university hospitals were reviewed retrospectively by trained abstractors. Information was collected about demographics, medical history, obstetric history, neonatal birth weight, complications, treatment, and outcome of the index pregnancy. The analysis was limited to women with singleton gestations with a history of 1 previous cesarean delivery. Because women with previous vaginal deliveries have higher vaginal birth after cesarean delivery success rates, the women were divided into four risk groups on the basis of their birth history. Groups were defined as women with no previous vaginal deliveries (group 1), women with a history of a previous vaginal birth after cesarean delivery (group 2), women with a history of a vaginal delivery before their cesarean delivery (group 3), and a group of women with a vaginal delivery both before and after the previous cesarean delivery (group 4). RESULTS: There were 9960 women with a singleton gestation and a history of one previous cesarean delivery. The overall vaginal birth after cesarean delivery success rate for the cohort was 74%. The overall vaginal birth after cesarean delivery success rates for groups 1, 2, 3, and 4 were 65%, 94%, 83%, and 93%, respectively. An analysis of neonatal birth weights of <4000 g, 4000 to 4249 g, 4250 to 4500 g, and >4500 g in group 1 showed a reduction in vaginal birth after cesarean delivery success rates from 68%, 52%, 45%, and 38%, respectively. In the remaining groups, there was no success rate below 63% for any of the birth weight strata. For group 1, vaginal birth after cesarean delivery success rates were decreased when the indication for the previous cesarean delivery was cephalopelvic disproportion or failure to progress or when the treatment was either an induction or augmentation of labor. The uterine rupture rate was higher in women for group 1 with birth weights of > or =4000 g (relative risk, 2.3; P <.001). CONCLUSION: Women with macrosomic fetuses and a history of a previous vaginal delivery should be informed of the favorable vaginal birth after cesarean delivery success rates. Given the risks of vaginal birth after cesarean delivery, those women with no history of a vaginal delivery should be counseled that the success rates may be <50% when the neonatal birth weight exceeds 4000 g and that the success rates may be even lower if the indication for the previous cesarean delivery was cephalopelvic disproportion or failure to progress or if the treatment requires either induction or augmentation of labor. The uterine rupture rate was 3.6% in women for group 1 with a birth weight > or =4000 g.