Association between prior vaginal birth after cesarean and subsequent labor outcome

Objective: To estimate the effect of prior successful vaginal birth after cesarean (VBAC) on the rate of uterine rupture and delivery outcome in women undergoing labor after cesarean.

Methods: A retrospective cohort study of all women attempting labor after cesarean delivery in a university-affiliated tertiary-hospital (2007–2014) was conducted. Study group included women attempting vaginal delivery with a history of cesarean delivery and at least one prior VBAC. Control group included women attempting first vaginal delivery following cesarean delivery. Primary outcome was defined as the rate of uterine rupture. Secondary outcomes were delivery and maternal outcomes.

Results: Of 62,463 deliveries during the study period, 3256 met inclusion criteria. One thousand two hundred and eleven women had VBAC prior to the index labor and 2045 underwent their first labor after cesarean. Women in the study group had a significantly lower rate of uterine rupture 9 (0.7%) in respect to control 33 (1.6%), p?=?.036, and had a higher rate of successful vaginal birth (96 vs. 84.9%, p?p?=?.04).

Conclusions: In women attempting labor after cesarean, prior VBAC appears to be associated with lower rate of uterine rupture and higher rate of successful vaginal birth.     

Effect of prior vaginal delivery or prior vaginal birth after cesarean delivery on obstetric outcomes in women undergoing trial of labor

OBJECTIVE: We sought to study the effects of prior vaginal delivery or prior vaginal birth after cesarean delivery (VBAC) on the success of a trial of labor after a cesarean delivery. METHODS: An observational study of patients who underwent a trial of labor after a single low-transverse cesarean delivery. Patients with a previous cesarean delivery and no vaginal birth were compared with patients with a single vaginal delivery before or after the previous cesarean delivery. The rates of successful VBAC, uterine rupture, and scar dehiscence were analyzed. Multivariable regression was performed to adjust for confounding variables. RESULTS: Of 2,204 patients, 1,685 (76.4%) had a previous cesarean delivery and no vaginal delivery, 198 (9.0%) had a vaginal delivery before the cesarean delivery, and 321 (14.6%) had a prior VBAC. The rate of successful trial of labor was 70.1%, 81.8%, and 93.1%, respectively (P <.001). A prior VBAC was associated with fewer third- and fourth-degree lacerations (8.5% versus 2.5% versus 3.7%, P <.001) and fewer operative vaginal deliveries (14.7% versus 5.6% versus 1.9%, P <.001) but not with uterine rupture (1.5% versus 0.5% versus 0.3%, P =.12). Patients with a prior VBAC had, in addition, a higher rate of uterine scar dehiscence (21.8%) compared with patients with a previous cesarean delivery and no vaginal delivery (5.3%; P =.001). CONCLUSION: A prior vaginal delivery and, particularly, a prior VBAC are associated with a higher rate of successful trial of labor compared with patients with no prior vaginal delivery. In addition, prior VBAC is associated with an increased rate of uterine scar dehiscence.     

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.     

Vaginal birth after cesarean section: Experience from a regional hospital

ObjectiveTrial of labor after cesarean section (TOLAC) is an option for women with previous cesarean section. However, few women choose this option because of safety concerns. We evaluate the safety and risks associated with TOLAC and the success rate of vaginal birth after cesarean delivery (VBAC).Material and methodsWe reviewed all patients with a history of previous cesarean section that underwent elective repeat cesarean section (ERCS) or TOLAC in a regional teaching hospital from Nov, 2013 to May, 2018. Maternal basic clinical information, intrapartum management, postpartum complications, and neonatal outcomes were analyzed.Results199 pregnant women with a history of at least one previous cesarean section were enrolled. 156 women received ERCS and 43 women (21.6%) underwent TOLAC, with 37 (86.0%) who underwent successful VBAC. The VBAC rate was 18.6%. Higher success rate was found in women with previous vaginal birth than in women without vaginal birth (100% vs. 81.8%). One case (2.3%) in the VBAC group was complicated with uterine rupture and inevitable neonatal death during second stage of labor. The uterus was repaired without maternal complications. In another case, the newborn's condition was complicated with low APGAR score (<7) at birth due to maternal chorioamnionitis. Among indications for previous cesarean section, cephalo-pelvic disproportion (CPD) was associated with TOLAC failure and uterine rupture after VBAC.ConclusionVBAC is a feasible and safe option. Modes of delivery should be thoroughly discussed when considering TOLAC for women with history of previous cesarean section due to CPD, considering its association with TOLAC failure in second stage of labor.     

Vaginal birth after cesarean in the diabetic gravida

OBJECTIVE: To compare the delivery outcomes in term diabetic patients without a prior cesarean delivery to those attempting vaginal birth after cesarean (VBAC). STUDY DESIGN: A retrospective chart review study was performed of singleton pregnancies complicated by class A-2-R diabetes who delivered at > or = 37 weeks from 1991 to 1997. Exclusion criteria were prior classical or low vertical cesarean, more than one prior cesarean delivery, fetal structural defects or any contraindications to labor. Outcome measures were compared for patients without prior cesarean (group 1) to those with a VBAC attempt (group 2). RESULTS: One hundred fifty-nine patients, 127 patients without a prior cesarean delivery and 32 patients with a VBAC attempt, met all the study criteria. The cesarean delivery rate was 26.3% (34/127) in group 1 and 56.3% (18/32) in group 2 (VBAC success rate, 43.7%). There were no cases of uterine rupture. There were no differences in the frequency of endometritis rates or neonatal intensive care unit admission, whether vaginal or cesarean delivery occurred. CONCLUSION: VBAC success rates appeared to be lower for diabetic gravidas as compared to those for nondiabetic women reported in the literature. Although maternal and neonatal complication rates were low, further studies are necessary to determine the safety of VBAC in this population.     

Vaginal birth after cesarean section: risk of uterine rupture with labor induction

We assessed the rate of uterine rupture in patients undergoing labor induction for attempted vaginal birth after cesarean (VBAC). A retrospective study was performed of data from a computerized database. Deliveries from January 1, 1998, to June 30, 2001, in the Southern California Kaiser Permanente system were reviewed and various perinatal characteristics analyzed. A total of 16,218 patients had a prior low transverse cesarean section. Of these, 6832 (42.1%) had a trial of labor. Successful VBAC occurred in 86% of patients with spontaneous onset of labor and 66% of patients with labor induction ( p < 0.001). The uterine rupture rate was not different between patients with spontaneous or induced labor (1.0% versus 1.2%, p = 0.51). Similarly, there was no significant difference between oxytocin or prostaglandin E2 induction (1.4% versus 1.0%, p = 0.59). In our study, labor induction did not appear to increase the risk of uterine rupture in women attempting VBAC.     

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.     

Previous preterm cesarean delivery: identification of a new risk factor for uterine rupture in VBAC candidates.

OBJECTIVE: A major risk of trials of labor in patients with prior cesarean delivery is uterine rupture. We evaluated the question of whether a previous cesarean delivery at an early gestational age predisposes the patient to subsequent uterine rupture. METHODS: This was a retrospective chart review of patients delivering at North Shore University Hospital with a trial of labor after previous cesarean delivery to ascertain all cases of uterine rupture. Patients who had had a previous cesarean delivery at our institution who did not suffer uterine rupture during a trial of labor served as controls. RESULTS: Twenty-five patients suffered a uterine rupture. The incidence of prior preterm cesarean delivery (PPCD) in this group was 40%, compared to 10.9% of 691 laboring vaginal birth after cesarean (VBAC) patients without rupture (p < 0.001). Patients in the rupture group with a PPCD were less likely to have experienced labor in the index pregnancy and more likely to have had an interdelivery interval of less than two years. CONCLUSIONS: An undeveloped lower segment in the preterm uterus represents a risk for later rupture, even if the incision is transverse.     

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.     

Uterine rupture in patients with a prior cesarean delivery: the impact of cervical ripening

The purpose of this study was to examine factors that were associated with uterine rupture in patients attempting vaginal birth after cesarean delivery. We analyzed the results of all patients attempting vaginal birth after cesarean delivery between September 1996 to December 1999 at a single institution using a contemporaneously maintained registry. Maternal factors, fetal factors, and management of labor were all assessed to determine the risk factors associated with symptomatic uterine rupture at the time of attempted vaginal birth after cesarean delivery. Twenty-eight symptomatic ruptures were identified in 972 attempts of vaginal birth after cesarean delivery at a gestational age greater than 24 weeks (2.88%). The use of preinduction cervical ripening was significantly associated with an increased risk of symptomatic uterine rupture (odds ratio, 3.92; 95% confidence interval, 1.78 to 8.62). Patients who underwent preinduction cervical ripening were significantly less likely to delivery vaginally than women who had not (46.71 versus 76.87%; p < 0.001). No other differences were noted between the two groups. Preinduction cervical ripening is associated with an increased risk of uterine rupture in women attempting vaginal birth after cesarean delivery.     

Intrapartum predictors of uterine rupture

This case-controlled study reviewed 26 cases of uterine rupture at an academic medical center. Controls were selected in a 2:1 design by reviewing the immediate successful vaginal birth after cesarean delivery (VBAC) before and after each case of uterine rupture. At less than 2 hours before delivery or acute uterine rupture, mild and severe variable decelerations, persistent abdominal pain, and hyperstimulation were more common in cases of uterine rupture as compared to controls and had statistically significant positive likelihood ratios (LR). Mild and severe variable fetal heart rate decelerations, especially in the presence of persistent abdominal pain, may predict uterine rupture in patients attempting VBAC.     

Interdelivery interval and the success of vaginal birth after cesarean delivery.

OBJECTIVE: To determine whether a short interdelivery interval is associated with decreased rate of successful vaginal birth after cesarean (VBAC). METHODS: A retrospective cohort study from January 1, 1997, to December 31, 2000, was conducted. Patients with previous cesarean delivery who attempted VBAC were identified. The analysis was limited to patients at term with one prior cesarean. The interdelivery interval was calculated in months between the index pregnancy and prior cesarean delivery. RESULTS: A total of 1516 subjects who attempted VBAC were identified among 24,162 deliveries, with complete data available in 1185 cases. The VBAC success rate was 79.0% for patients with an interdelivery interval less than 19 months compared with 85.5% for patients with an interval delivery greater than or equal to 19 months (P =.12). For patients whose labors were induced, interdelivery intervals of less than 19 months were associated with a decreased rate of VBAC success when compared with longer intervals (P <.01). Sufficient power (beta =.95) existed to detect a 64% difference between the groups (alpha =.05). No significant difference was detected in women who underwent spontaneous labor (P =.98). There was no difference in the rate of symptomatic uterine rupture (P = 1.00). CONCLUSION: Interdelivery intervals of less than 19 months were associated with a decreased rate of VBAC success in patients who underwent induction, a difference not found in those with spontaneous labor.     

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.     

Single- versus double-layer uterine incision closure and uterine rupture.

OBJECTIVE: To evaluate whether closure of the uterine incision with one or two layers changes uterine rupture or vaginal birth after cesarean section (VBAC) success rates. METHODS: Subjects with one previous cesarean section by documented transverse uterine incision that attempted VBAC were identified. Exclusion criteria included lack of documentation of the type of closure of the previous uterine incision, multiple gestation, more than one previous cesarean section, and previous scar other than low transverse.Uterine rupture and VBAC success rates were compared between those with single-layer and double-layer uterine closure. Time interval between deliveries, birth weight, body mass index (BMI), and history of previous VBAC were evaluated as possible confounders. RESULTS: Of 948 subjects identified, 913 had double-layer closure and 35 had single-layer closure. The uterine rupture rate was significantly higher in the single-layer closure group (8.6% vs. 1.3%, p = 0.015). This finding persisted when controlling for previous VBAC, induction, birth weight >4000 g, delivery interval >19 months, and BMI >29 (OR 8.01, 95% CI 1.96-32.79). There was no difference in VBAC success rate (74.3% vs. 77%, p = 0.685). CONCLUSION: Single-layer uterine closure may be more likely to result in uterine rupture.     

Uterine rupture with the use of PGE2 vaginal inserts for labor induction in women with previous cesarean sections

OBJECTIVE: To analyze the rate of uterine rupture in women with previous cesarean sections undergoing a trial of labor in which a prostaglandin E2 (PGE2) vaginal insert was used. STUDY DESIGN: The study was based on a computerized search and review of pharmacy records, medical records and the pertinent literature. Pharmacy records were correlated with the medical records of all women undergoing a trial of labor after cesarean section over a 33-month period. RESULTS: Between January 1998 and September 2000, 13,544 patients delivered. Of these cases, 790 were vaginal trials of labor after previous cesarean section. A PGE2 vaginal insert was used in 58 of the patients. A total of 6 of these 58 patients (10.3%) experienced uterine rupture. This compares to a rupture rate of 1.1% (8/732) in deliveries not using PGE2 vaginal inserts. CONCLUSION: The risk of uterine rupture was significantly increased in patients undergoing a trial of labor after previous cesarean section when a PGE2 vaginal insert was used. Physicians need to be aware that using a PGE2 vaginal inserts for cervical ripening and/or induction of labor in women with a previous cesarean section might increase the risk of uterine rupture above the standard risk for vaginal birth after cesarean (VBAC) candidates. We recommend that all VBAC patients using a PGE2 vaginal insert be closely monitored for evidence of uterine rupture.     

Uterine rupture associated with the use of misoprostol in the gravid patient with a previous cesarean section

Objective: Our purpose is to report our experience with uterine rupture in patients undergoing a trial of labor after previous cesarean delivery in which labor was induced with misoprostol. The literature on the use of misoprostol in the setting of previous cesarean section is reviewed. Study Design: This report was based on case reports, a computerized search of medical records, and literature review. Results: Uterine rupture occurred in 5 of 89 patients with previous cesarean delivery who had labor induced with misoprostol. The uterine rupture rate for patients attempting vaginal birth after cesarean section was significantly higher in those who received misoprostol, 5.6%, than in those who did not, 0.2% (1/423, P = .0001). Review of the literature reveals insufficient data to support the use of misoprostol in the patient with a previous cesarean delivery. Conclusion: Misoprostol may increase the risk of uterine rupture in the patient with a scarred uterus. Carefully controlled studies of the risks and benefits of misoprostol are necessary before its widespread use in this setting. (Am J Obstet Gynecol 1999;180:1535-42.)     

Risk of uterine rupture with a trial of labor in women with multiple and single prior cesarean delivery

OBJECTIVE: To determine whether the risk for uterine rupture is increased in women attempting vaginal birth after multiple cesarean deliveries. METHODS: We conducted a prospective multicenter observational study of women with prior cesarean delivery undergoing trial of labor and elective repeat operation. Maternal and perinatal outcomes were compared among women attempting vaginal birth after multiple cesarean deliveries and those with a single prior cesarean delivery. We also compared outcomes for women with multiple prior cesarean deliveries undergoing trial of labor with those electing repeat cesarean delivery. RESULTS: Uterine rupture occurred in 9 of 975 (0.9%) women with multiple prior cesarean compared with 115 of 16,915 (0.7%) women with a single prior operation (P = .37). Multivariable analysis confirmed that multiple prior cesarean delivery was not associated with an increased risk for uterine rupture. The rates of hysterectomy (0.6% versus 0.2%, P = .023) and transfusion (3.2% versus 1.6%, P < .001) were increased in women with multiple prior cesarean deliveries compared with women with a single prior cesarean delivery attempting trial of labor. Similarly, a composite of maternal morbidity was increased in women with multiple prior cesarean deliveries undergoing trial of labor compared with those having elective repeat cesarean delivery (odds ratio 1.41, 95% confidence interval 1.02-1.93). CONCLUSION: A history of multiple cesarean deliveries is not associated with an increased rate of uterine rupture in women attempting vaginal birth compared with those with a single prior operation. Maternal morbidity is increased with trial of labor after multiple cesarean deliveries, compared with elective repeat cesarean delivery, but the absolute risk for complications is small. Vaginal birth after multiple cesarean deliveries should remain an option for eligible women. LEVEL OF EVIDENCE: II-2.     

Safety and efficacy of attempted vaginal birth after cesarean beyond the estimated date of delivery.

OBJECTIVE: To provide data regarding safety and efficacy for women attempting a trial of labor following earlier cesarean birth who have reached their due date. STUDY DESIGN: A computerized data base was analyzed to identify women who were at or beyond 40 weeks of gestation between January 1, 1995, and March 31, 1996. Ninety women attempted vaginal birth after cesarean (VBAC) during the study period; 90 controls were matched for age, race and parity. Delivery route and complications were outcome variables identified. RESULTS: The rate of successful VBAC was 65.6% as compared to the 94.4% vaginal delivery rate among women who had not had a prior cesarean (P < .0001). Among women attempting VBAC, 62% of those who had no prior vaginal births successfully delivered vaginally, while 82% of women with one prior vaginal birth delivered vaginally (P < .0001). Women of greater parity were more successful at a trial of labor. Infectious morbidity was more common among women attempting VBAC than among those with no prior cesarean. CONCLUSION: The patient and her family can be reassured that passing her due date does not alter the efficacy or safety of a trial of labor. No change in counseling is warranted simply due to the completion of 40 weeks' gestation.     

Outcome of subsequent delivery after a previous early preterm cesarean section.

OBJECTIVE: To determine the vaginal birth after cesarean section (VBAC) rate and risk of uterine rupture in women with a previous early preterm cesarean section. METHODS: Women who delivered their first child by cesarean section between 26 and 34 weeks of gestation were included in a retrospective cohort study. Medical charts were reviewed for characteristics of the index pregnancy and delivery. Information of the subsequent delivery was obtained from the medical charts or from information of the attending gynecologist if the delivery was elsewhere. RESULTS: Two hundred and forty-six women were included: 131 (53.3%) women had a subsequent pregnancy, 64 (26.0%) had no subsequent pregnancy, and from 51 (20.7%) women no information could be obtained. Of the 131 women with a subsequent pregnancy, 93 (71.0%) underwent a trial of labor (TOL) and 80 (86.0%) achieved a vaginal delivery, resulting in a VBAC rate of 61.1%. One uterine rupture occurred with favorable neonatal outcome. The uterine rupture rate for the whole cohort was 0.8% (95% CI 0.02-4.0) and for the group of women undergoing a TOL 1.1% (95% CI 0.03-5.8). CONCLUSION: In this small series of women with a previous early preterm cesarean section the VBAC rate was high (61.1%) and the uterine rupture rate was 1.1%.     

The counselling of patient with prior C-section

A trial of labor after prior cesarean delivery is associated with a greater perinatal risk than is elective repeated cesarean delivery without labor, although absolute risks are low. Information and counselling aim to estimate specific risks and to balance these risks according to individual factors. Therefore, the physician has to answer two questions: (i) which would be the probability of successful vaginal delivery? (ii) which would be the risk of uterine rupture with a trial of labor? The risk factors for failure of trial of labor are: increased maternal age, obesity, and fetal macrosomia. The risk factors for uterine rupture are: increased maternal age, postpartum fever after the previous cesarean delivery, short interdelivery interval, history of at least two previous cesarean deliveries, and a history of classical incision. Conversely, other factors are of good prognosis: a prior vaginal delivery and, particularly, a prior VBAC (Vaginal Birth After Caesarean) are associated with a higher rate of successful trial of labor compared with patients with no prior vaginal delivery; ultrasonographic measurement of the lower uterine segment thickness>3.5 mm has an excellent negative predictive value for the risk of uterine defect. Finally, the wish for additional pregnancies following a cesarean section must be considered as an argument in favour of a trial of labor after accounting for the increasing risks correlated with repeated elective cesarean deliveries.