Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence.
INTRODUCTION — For women who have undergone a previous cesarean delivery, optimum management of subsequent deliveries has been debated for over 100 years [1-5]. The two options are trial of labor after cesarean delivery (TOLAC) and elective repeat cesarean delivery (ERCD).
This topic will review issues related to choosing the route of delivery after cesarean birth as well as management of a trial of labor in this setting. Uterine rupture is an infrequent but serious complication in women who attempt TOLAC and is discussed in detail separately. (See "Uterine rupture after previous cesarean delivery".)
BACKGROUND — In 1980, a National Institutes of Health Consensus Development Conference report questioned the necessity of routine ERCD and, with endorsement from the American College of Obstetricians and Gynecologists (ACOG) [6-8], encouraged clinicians and patients to increase the rate of TOLAC, with great success: The TOLAC rate reached a peak of 51.8 percent in 1995, with a concomitant decline in total cesarean delivery rates in the United States .
As the TOLAC rate increased, however, so did reports of uterine rupture-related maternal and perinatal morbidity [10-14]. These adverse outcomes dampened enthusiasm for TOLAC. They also prompted ACOG to issue a practice bulletin in 1998 that cautioned TOLAC should only be attempted in appropriately equipped institutions with clinicians "readily" available to provide emergency care . Within nine months, ACOG revised the practice bulletin to say that clinicians should be "immediately" available , a position endorsed by the American Society of Anesthesiologists [17,18]. This one-word change was associated with a decade-long decline in national TOLAC rates, which reached a nadir of 15.9 percent in 2006 before increasing again . Two surveys of hospital administrators found that 30 percent of hospitals discontinued allowing TOLAC because they were unable to comply with the immediately available requirement for surgical and anesthesia services, and of the hospitals who continued to offer TOLAC, over half made changes in their policies to accommodate ACOG recommendations [19-21].
Fear of catastrophic complications associated with TOLAC may be one reason providers avoid encouraging TOLAC for their patients [19,22]. Concerns about medical liability claims have also contributed to reduced access to TOLAC [23-25]. For example, a 2009 Survey of Professional Liability by ACOG found that 91 percent of members who responded reported at least one liability claim against them in their career; 62 percent of claims within the survey period were related to obstetric care . Of those who made changes in their obstetric practice as a result of risk or fear of liability, 25 percent stopped offering TOLAC.
In spite of these concerns, it is important to remember that a successful uncomplicated TOLAC has many short- and long-term benefits (see 'Risks and benefits of TOLAC versus ERCD' below). In a Markov model, when the likelihood of success was ≥47 percent, TOLAC was more effective and less expensive than ERCD . The cost-effectiveness improves in patients who undergo multiple subsequent vaginal deliveries .
LIMITATIONS OF AVAILABLE EVIDENCE — No large randomized trials have been performed to provide comparative data on outcomes of TOLAC versus ERCD; a systematic review identified only two randomized trials involving 320 women with minimal data for maternal and infant clinical outcomes .
It is important to recognize that many case-control and cohort studies that compared these two routes of delivery reported maternal and neonatal outcomes based on the actual route of delivery rather than the intended route. If this type of analysis is performed, the outcomes of women who undergo cesarean delivery after an unsuccessful TOLAC are grouped along with the outcomes of women undergoing ERCD, which is a less morbid procedure. In addition, the outcomes of women who planned ERCD but spontaneously labored and were delivered vaginally are grouped along with the outcomes of women who had a successful TOLAC. This method of analysis leads to misleading conclusions about the actual risk of adverse events or outcomes associated with the decision to attempt TOLAC or ERCD. Analysis of available data is also complicated by imprecise definitions and outcome measurements as well as difficulties encountered when trying to characterize events and outcomes attributable to route of delivery.
In 2010, the National Institute of Child Health and Human Development and the Office of Medical Applications of Research of the National Institutes of Health convened a Consensus Development Conference to study these issues . Their final report summarized the state of knowledge concerning the risks and benefits of ERCD versus TOLAC in women who have undergone one or more prior cesarean deliveries. These findings and subsequent data are described throughout this topic.
RISKS AND BENEFITS OF TOLAC VERSUS ERCD
Overview — There are two possible intended management options (intended TOLAC versus intended ERCD) that can lead to three possible outcomes for the woman who has had a prior cesarean delivery: an ERCD, a successful trial of labor culminating in vaginal birth, or a failed TOLAC resulting in a repeat cesarean delivery during labor. The medical and obstetric benefits of successful TOLAC derive from avoidance of the risks associated with repeat cesarean delivery, especially multiple cesarean deliveries: Most maternal morbidity associated with TOLAC occurs when intrapartum cesarean delivery becomes necessary. Conversely, the medical and obstetrical benefits of ERCD derive from avoidance of the risks associated with TOLAC, primarily uterine rupture. Thus, the benefits of TOLAC are closely related to having a successful vaginal birth, which has the lowest morbidity of the three possibilities. A failed TOLAC has higher morbidity than successful TOLAC or ERCD, especially if failed TOLAC is associated with uterine rupture, which can be fatal for the mother or child .
Maternal — The following table summarizes available evidence of maternal risks associated with TOLAC and ERCD (table 1); it was derived from a 2010 systematic review of 41 studies . A limitation of these data is that the studies reported outcomes based on the actual route of delivery rather than the intended route. This is important because maternal morbidity is higher when cesarean delivery is performed during labor. Selected risks of TOLAC are discussed below:
●Uterine rupture – The incidence of uterine rupture is low (in resource-rich countries), but when it occurs, it is often associated with TOLAC and potentially life-threatening. The National Institute of Child Health and Human Development consensus conference panel described uterine rupture risk in the following way , based on data in the 2010 systematic review :
•In a hypothetical group of 100,000 women of any gestational age who undergo TOLAC, there will be 468 cases of uterine rupture. Looked at in another way, these data suggest that approximately 1 in 200 TOLACs will lead to uterine rupture.
•In a hypothetical group of 100,000 women of any gestational age who undergo ERCD, there will be 26 uterine ruptures.
The types and frequencies of major maternal and neonatal outcomes of uterine rupture include:
•Hysterectomy: 14 to 33 percent .
•Maternal death: 0.21 percent (4 deaths out of 1879 cases of uterine rupture without pre-existing conditions) .
•Neonatal death: 5 percent, adjusted odds ratio 65 .
•Severe neonatal neurologic morbidity: 6 to 8 percent [32,33].
●Infection – Although the overall risk of infection appears to be similar for TOLAC and ERCD , specific risks vary by clinical setting. For example, only women in labor are at risk for intrapartum chorioamnionitis. Successful TOLAC has a lower frequency of postpartum infection than ERCD, while intrapartum cesarean delivery has the highest frequency of postpartum infection .
●Peripartum hysterectomy – Although some peripartum hysterectomies are performed because of uterine rupture during TOLAC, many others are performed because of placenta accreta. An increasing number of cesarean deliveries increases the risk for placenta previa and, in turn, placenta accreta. (See "Clinical features and diagnosis of the morbidly adherent placenta (placenta accreta, increta, and percreta)", section on 'Risk factors'.)
●Other – ERCD avoids the potential risks and sequelae of pelvic trauma related to labor and vaginal birth; however, the magnitude of this effect compared with TOLAC is unclear and does not appear to outweigh the risks of ERCD. Pregnancy itself is the major risk factor for future pelvic relaxation disorders. (See "Urinary incontinence and pelvic organ prolapse associated with pregnancy and childbirth".)
For many patients, a benefit of ERCD is that scheduled delivery allows her and her family the ability to make specific work-life plans for the delivery and postpartum period. Although induction of labor can also be scheduled, TOLAC is safer when labor is spontaneous and thus somewhat unpredictable. Personal benefits of successful TOLAC include shorter hospital stay and quicker return to normal activities compared with ERCD.
Postpartum sterilization is readily accomplished at cesarean delivery; however, this is a minor advantage of ERCD since sterilization can be performed after a vaginal birth and often immediately following the birth.
Neonatal — Evidence for short- and long-term neonatal outcomes after TOLAC versus ERCD is limited . As discussed above, most of the available evidence documents differences comparing actual rather than intended mode of delivery and is of low quality due to inconsistent and imprecise outcome measures. The 2010 systematic review discussed above reported the following neonatal outcomes relating to TOLAC :
●Perinatal mortality and neonatal mortality rates were higher with TOLAC than for ERCD (perinatal mortality rate: 0.13 versus 0.05 percent; neonatal mortality rate: 0.11 versus 0.06), although the absolute risk is very low.
●Transient tachypnea of the newborn was more common with ERCD compared with TOLAC (4.2 versus 3.6 percent). However, neonatal bag and mask ventilation was used more often in infants delivered following TOLAC than in those delivered by ERCD (5.4 versus 2.5 percent).
●Data were insufficient to determine the direction of risk for hypoxic ischemic encephalopathy, sepsis, trauma, neonatal intensive care unit (NICU) admission, and neurologic outcomes.
Subsequent studies have observed that the rates of suspected and proven neonatal sepsis are higher for TOLAC than ERCD (suspected sepsis 5 versus 2 percent; proven sepsis 1 versus 0 percent)  and observed an increased risk of neonatal depression and NICU admission with TOLAC versus ERCD [36,37].
SHARED DECISION-MAKING — Planning the route of delivery for the woman who has had a previous cesarean delivery should be addressed early in her prenatal care and can begin preconceptionally. The decision for TOLAC or ERCD should be a collaborative process between patients and their providers that takes into account the best clinical evidence available as well as the patient's values and preferences. Whenever possible, the woman's preference should be honored [19,22]. Ongoing discussion at intervals throughout pregnancy is important, as conditions may arise that alter the balance of risks and benefits of the planned route of delivery.
Individual patient factors that impact the risks and benefits for each delivery method should be discussed. This is especially important for women who are potentially at higher risk of uterine rupture and its attendant sequelae and women who may have more than two cesarean deliveries. (See 'Candidates for TOLAC' below.)
Factors known to affect TOLAC success rates and the patient's likelihood of success obviously need to be addressed. Between 1990 and 2009, the success rate for women in the United States who attempted TOLAC ranged from 39 to 70 percent . The success rate varies among institutions and providers and is affected by antepartum, intrapartum, and nonmedical factors . (See 'Candidates for TOLAC' below.)
A woman's decision regarding route of delivery is also influenced by other factors. Common reasons women choose TOLAC include a prior successful vaginal delivery since it is associated with an increased chance of successful TOLAC and decreased risk of uterine rupture, future pregnancy plans since multiple cesarean deliveries increase the risk for placenta previa/accreta, family obligations making a speedy return to normal activities postpartum desirable, the desire to experience a natural birth, and desire for their partners' involvement in labor and birth. Common reasons women choose ERCD include scheduling convenience, ease of sterilization at the time of delivery, fear of failed trial of labor and emergency cesarean delivery, and avoidance of labor pain [19,22]. In addition, women report that their health care providers' recommendations and preferences exert a strong influence on their decision whether or not to pursue TOLAC .
Unlike most medical decisions where patients are comparing risks and benefits for themselves, the pregnant patient must compare risks and benefits for both herself and her fetus, and the risks and benefits for these two individuals sometimes do not align: A decision that increases maternal risk may be associated with fetal benefit. It should be noted that most pregnant women are willing to tolerate a high degree of risk to themselves in exchange for zero or near-zero risk for their child [39,40]. Though, occasionally, the desire to achieve a natural birth can lead to increasing the risk to their child as in the case of the out-of-hospital TOLAC [41,42].
Decision aids — A number of patient-oriented information and decision aids are available to help patients make an informed decision about TOLAC versus ERCD. In the United States, patient information is available from the American College of Obstetricians and Gynecologists and from the National Library of Medicine.
Online tools or decision aides can be used as an adjunct to provider consultation. They are designed to communicate evidence-based information to help patients better understand childbirth choices, establish their personal priorities, and ultimately decide whether or not to pursue a TOLAC. One example is from the Queensland Centre for Mothers and Babies.
A prospective study found that many patients with a prior cesarean are insufficiently informed of the complexities of the issues when they make their decision on route of delivery . Although a Cochrane review found that the use of decision support tools used independently by the patient ultimately made no difference in the type of birth (TOLAC versus ERCD) women planned, the use of these tools reduced feelings of uncertainty about their decision .
CANDIDATES FOR TOLAC
Overview — The ideal candidates for TOLAC are women with a high likelihood of vaginal delivery and a very low likelihood of intrapartum uterine rupture. The paucity of definitive data predictive of these outcomes makes selecting ideal candidates challenging.
The authors do not use calculators or other tools to predict TOLAC outcome. A number of predictive models, screening tools, and nomograms have been developed to identify women with a prior cesarean delivery who have a high or low likelihood of successful TOLAC, but none have been proven to be highly useful clinically [19,22,44-47]. These screening tools use a combination of obstetric factors, such as maternal demographics (age, race, ethnicity, body mass index [BMI]); the indication(s) for the prior cesarean delivery; the type and number of prior hysterotomy incisions; previous vaginal deliveries, either before or after the cesarean delivery; cervical favorability (eg, Bishop score at the time of admission for spontaneous or planned induction of labor); and intrapartum interventions (eg, labor induction or augmentation) . One review concluded that scored screening tool models incorporating various combinations of the above predictive factors reasonably predicted successful TOLAC but were unable to consistently identify women at risk for failed TOLAC . The use of calculators as part of the process of counseling women about TOLAC is reviewed in detail separately. (See "Use of calculators and models for predicting vaginal birth after a previous cesarean delivery".)
There is also no reliable method for predicting uterine rupture in women with a prior cesarean delivery. Likelihood of rupture is estimated primarily by type of hysterotomy incision and presence/absence of risk factors; some clinicians also perform sonographic evaluation of the hysterotomy scar. Methods for prediction of uterine rupture and their performance are reviewed separately. (See "Uterine rupture after previous cesarean delivery", section on 'Predicting uterine rupture'.)
One prior low transverse uterine incision — There is good and consistent evidence that a woman who has undergone only one previous cesarean delivery performed using a transverse lower segment hysterotomy incision has the lowest risk of uterine scar separation during a subsequent trial of labor; thus, TOLAC is a reasonably safe option for delivery for these women [19,22]. In this setting, the body of evidence suggests a TOLAC success rate of 60 to 80 percent , with an estimated uterine rupture rate of 0.4  to 0.7 percent . Success rates are higher in patients with additional characteristics, such as a prior vaginal delivery.
Characteristics that increase the probability of successful TOLAC in this population — For women who are optimal candidates for TOLAC, the highest success rates (over 80 percent) occur in those with:
●A successful vaginal delivery before or after their primary cesarean delivery – These women are significantly more likely to have a successful TOLAC than those who have never delivered vaginally (odds ratio [OR] for successful TOLAC with prior vaginal delivery 3.90, 95% CI 3.60-4.30; with prior successful TOLAC 4.76, 95% CI 4.35-5.26) . In addition, one study reported that women with a previous vaginal delivery had one-fifth the risk of uterine rupture during TOLAC compared with women without prior vaginal delivery (0.2 versus 1.1 percent) .
●A nonrecurrent indication for their primary cesarean delivery – The rate of successful TOLAC by indication for prior cesarean delivery is approximately 75 percent for fetal malpresentation, 60 percent for nonreassuring fetal heart rate pattern, and 54 percent for failure to progress or cephalopelvic disproportion [22,51].
●Spontaneous labor on admission to the labor unit – When admitted to the labor unit, women in spontaneous labor or with >4 cm cervical dilation are more likely to have successful TOLAC than women without these characteristics (OR for successful TOLAC with spontaneous labor, induction, augmentation 1.0, 0.50, 0.68, respectively; for admission cervical examination >4 cm 2.56, 95% CI 2.38-2.67) [22,51].
Additional characteristics that increase the probability of successful TOLAC are discussed below.
●Fetal weight less than 4000 g – An estimated fetal weight >4000 g halves the likelihood of successful TOLAC (successful TOLAC for birth weight >4000 g OR 0.55, 95% CI 0.49-0.61) [22,51,53,54].
●Demographic factors – Hispanic, African American, and Asian women are more likely to pursue a TOLAC but are less likely to have a successful TOLAC when compared with non-Hispanic white women (OR for successful TOLAC for non-Hispanic Caucasians, African Americans, and Hispanics: 1, 0.69, and 0.65, respectively) [22,44,51,55-57].
Women over 35 years of age are less likely to pursue a TOLAC; those who attempt TOLAC are less likely to have a successful TOLAC and more likely to experience TOLAC-associated complications than younger women .
The likelihood of successful TOLAC increases with increasing maternal height (for each 5 cm maternal height increase the OR for successful TOLAC is 1.33, 95% CI 1.28-1.37) and is lower in obese women (for BMI >30 kg/m2, the OR for successful TOLAC is 0.55, 95% CI 0.51-0.60) [44,51,59].
●Interpregnancy interval more than six months – An interpregnancy interval of more than six months is desirable, as an interval of less than six months is an independent risk factor for both uterine rupture and maternal morbidity during TOLAC. (See "Interpregnancy interval and obstetrical complications".)
●Absence of maternal medical disease – Data on the effect of pre-existing maternal medical disease on the outcome of a TOLAC are inconclusive. Several cohort studies of women with pre-existing maternal disease, such as hypertension, diabetes, asthma, renal disease, and heart disease, reported a reduced likelihood of successful TOLAC [51,56,60]. In one prospective study, however, there were no significant differences in the rates of successful TOLAC in women with these medical disorders .
●Delivery in a university hospital – University hospitals or hospitals affiliated with an obstetrics and gynecology residency program have higher rates of TOLAC and successful TOLAC [54,61,62]. Women who deliver at a private or rural hospital have a decreased likelihood that TOLAC will be attempted and, if attempted, a decreased rate of successful TOLAC when compared with a tertiary care or perinatal center . As an example, a study that compared successful TOLAC rates across hospital settings in California reported rates of successful TOLAC (adjusted for baseline and medical characteristics of mother and fetus) as 14 percent in private nonteaching hospitals, 57 percent in public hospitals, 60 percent in private teaching hospitals, and 41 percent in health maintenance organizations .
Possibly appropriate candidates — Women who are possibly appropriate candidates for TOLAC have a reasonable likelihood of success but lower than in optimal candidates. They also have a low likelihood of uterine rupture, but data regarding their risk of uterine rupture are more limited than in optimal candidates and based on sparse or inconsistent scientific evidence.
The American College of Obstetricians and Gynecologists (ACOG) has opined that women with the following clinical characteristics can be considered candidates for TOLAC, after appropriate individualized risk assessment and counseling :
Prior low vertical uterine incision — Data are limited and inconclusive regarding risk of uterine rupture in women with a prior low vertical uterine incision. A literature review concluded the frequency of rupture for low transverse incisions ranged from 0.4 to 0.7 percent versus 1.05 to 2.0 percent for low vertical uterine incisions . The authors do not offer TOLAC to women with a prior low vertical uterine incision, but our approach is not universal.
Two prior low transverse uterine incisions — The likelihood of successful TOLAC appears to be similar for women with one versus two prior cesarean deliveries (65 to 75 percent) [66-68]; however, women with more than one prior cesarean appear to have a higher rate of uterine rupture . In a 2010 systematic review with meta-analysis of five cohort studies of uterine rupture in women with prior cesarean deliveries, women undergoing TOLAC after two prior cesareans were at significantly higher risk of rupture than those with one prior cesarean (1.59 versus 0.72 percent; OR 0.42, 95% CI 0.29-0.60); however, the definition of rupture varied among studies . The authors do not offer TOLAC to women with two prior low transverse uterine incisions, but our approach is not universal.
Unknown type of uterine incision — The prior incision type is not always available when caring for a woman in her subsequent pregnancy. Because most women with a prior uterine incision for common obstetrical indications have had a low-transverse hysterotomy incision, some authors suggest making the decision for TOLAC based on this assumption. This approach is supported by data from two large studies that found women who had an unknown type of prior incision had a similar rate of uterine rupture as those with a known prior low transverse uterine incision [34,69]. As an example, uterine rupture occurred in 0.5 percent of women with an unknown scar type and 0.7 percent of women with a known low transverse incision in the National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network study .
There are a few indications for cesarean delivery that increase the probability of a prior vertical incision, such as breech delivery remote from term or transverse lie; thus, the circumstances of the prior cesarean delivery should be considered in estimating whether the patient is at increased risk of uterine rupture when the operative report is unavailable.
The authors do not offer TOLAC to women with an unknown uterine incision, but our approach is not universal.
Pregnancy more than 40 weeks of gestation — Studies have consistently observed that women who attempt TOLAC beyond 40 weeks of gestation are less likely to successfully deliver vaginally [19,53,65,70]. In addition, there are at least two reports that have described a 2 to 3 percent risk of uterine rupture in these women [71,72].
The authors discuss both of these issues with patients who are planning TOLAC and offer induction of labor by amniotomy at 40 weeks of gestation if the cervix is favorable. If the cervix is unfavorable, mechanical cervical ripening followed by amniotomy and oxytocin administration is an option. (See "Cervical ripening and induction of labor in women with a prior cesarean delivery".)
Twin gestation — While most studies report that women with a twin gestation are significantly less likely to pursue TOLAC, the overall success rate and risk of uterine rupture in this population appears to be similar to that in singleton gestations undergoing TOLAC [73-75]. ACOG has opined that women with twin pregnancies and one previous low transverse cesarean delivery are candidates for TOLAC if they have no contraindications to vaginal birth . The authors do not offer TOLAC to women with twin gestations, but our approach is not universal. (See "Twin pregnancy: Labor and delivery", section on 'Trial of labor after previous cesarean delivery'.)
Macrosomia — When counseling women regarding TOLAC, ACOG has opined that suspected fetal macrosomia alone should not preclude the option of a TOLAC . Clinicians should consider whether the woman has had a previous vaginal delivery, past birth weight(s) and outcomes, and the predicted birth weight in the current pregnancy. However, prophylactic cesarean delivery has been suggested when the estimated fetal weight is ≥5000 grams in women without diabetes and ≥4500 grams in women with diabetes .
For women with no previous vaginal delivery, the likelihood of successful TOLAC falls to ≤50 percent when birth weight increases above 4000 grams [78,79]. In one study of TOLAC among such women, newborn birth weights <4000 grams, 4000 to 4249 grams, 4250 to 4500 grams, and >4500 grams were associated with vaginal birth after cesarean in 68, 52, 45, and 38 percent of cases, respectively . Success rates were lower if the indication for the previous cesarean delivery was cephalopelvic disproportion or failure to progress or if the woman required either induction or augmentation of labor during TOLAC. In contrast, women who had a previous vaginal delivery had a ≥63 percent rate of vaginal birth after cesarean for any of the birth weight strata.
It also should be noted that women attempting TOLAC with no prior vaginal delivery and/or newborn birth weight >4000 grams may have a higher likelihood of adverse obstetrical outcomes, such as uterine rupture [78,80,81]. In one study, women attempting TOLAC with both no prior vaginal delivery and newborn birth weight ≥4000 grams had a 3.6 percent uterine rupture rate .
Maternal diabetes — Rates of successful TOLAC in women with gestational and pregestational diabetes appear to be lower compared with nondiabetic women undergoing TOLAC [82-84]. The authors do not offer TOLAC to women whose pregnancies are complicated by gestational or pregestational diabetes, but our approach is not universal.
Maternal obesity — Observational studies have consistently reported that a trial of labor after a cesarean delivery is less likely to result in vaginal birth in obese gravidas [22,44,51,84-89]. The largest of these studies was a prospective multicenter study including 6413 obese and 1638 severely obese women . The rate of failed trial of labor was 15 percent in normal-weight women, 30 percent in obese women, and 39 percent in severely obese women. The rate of uterine dehiscence/rupture for the three groups was 0.9, 1.4, and 2.1 percent, respectively.
No guidelines have addressed whether TOLAC should be avoided in severely obese women or at any threshold BMI. The authors do not have a specific limitation related to BMI.
Inappropriate candidates — Most clinicians, including these authors, believe the risks of TOLAC outweigh the benefits in the following settings :
High-risk uterine scars — Types of prior hysterotomy incisions that have an unacceptably high risk for uterine rupture during TOLAC include classical, T, or J incisions as well as transfundal incisions or myoma resections that extend into the myometrium. In the literature review discussed above, the frequency of rupture for classical or T-shaped incisions ranged from 4.0 to 9.0 percent, which is at least two-fold higher than the upper estimate of rupture risk for low vertical incisions and more than five-fold higher than the upper estimate of rupture risk for low transverse incisions .
A NICHD MFMU Network study of TOLAC evaluated the outcome of women with prior classical or either inverted T or J incision who presented in advanced labor or declined repeat cesarean delivery . The uterine rupture rate was lower in this study, 1.9 percent, but still unacceptably high. A subsequent retrospective study of women attempting TOLAC found that a prior inadvertent uterine extension at the time of primary cesarean was associated with an increased risk of uterine rupture when compared with no prior extension (6.0 versus 1.5 percent) .
Prior uterine rupture — Women who have experienced a previous uterine rupture confined to the lower uterine segment are reported to have a high incidence (6 percent) of recurrent uterine rupture with labor [91-95]. Women in whom the prior rupture involved the upper uterine segment have experienced a repeat rupture rate as high as 32 percent . In a 25-year literature review, 22 women identified to have uterine rupture subsequently became pregnant again . Twenty underwent ERCD at term; the other two women died following catastrophic uterine rupture at 32 and 35 weeks of gestation. Although the overall quality of this evidence is low, the risk of rupture in these patients is likely unacceptably high. (See "Repeat cesarean delivery", section on 'Previous classical incision'.)
Women with prior uterine rupture, prior classical cesarean delivery, or prior hysterotomy for fetal surgery  are all at increased risk of scar dehiscence or rupture in subsequent pregnancy and thus should undergo delivery by ERCD by 37 weeks of gestation. Management of these pregnancies are reviewed separately. (See "Uterine rupture after previous cesarean delivery", section on 'Management of subsequent pregnancies'.)
Prior uterine dehiscence — For women who have experienced a prior uterine scar dehiscence and repair, the likelihood of subsequent uterine rupture with potential catastrophic outcome is unclear. There have been isolated reports of both antepartum and interpregnancy uterine scar repairs followed by successful pregnancies; however, numbers are small and await confirmation on a larger scale. While consensus recommendations for the management of these women are not available, the authors do not offer TOLAC and plan delivery by ERCD at 37 weeks of gestation [97,98]. (See "Uterine rupture after previous cesarean delivery", section on 'Recurrence risk'.)
Contraindication to vaginal delivery — ERCD should be performed when standard obstetrical contraindications to vaginal delivery are present, such as placenta previa or footling breech presentation.
Fetal demise — The balance of risks and benefits is different in the setting of fetal demise since ERCD has no perinatal benefit. Decision-making on the route of delivery in these cases is reviewed separately. (See "Fetal death and stillbirth: Maternal care".)
MANAGEMENT OF LABOR AND DELIVERY — Intrapartum management of patients undergoing TOLAC is similar to that in patients with an unscarred uterus, except they are more closely monitored for signs of uterine rupture, especially when uterotonic agents are administered.
Facilities and personnel — The ability to perform emergency cesarean delivery is a prerequisite for attempting TOLAC in women with any type of prior hysterotomy incision. The American College of Obstetricians and Gynecologists (ACOG) recommends that TOLAC be undertaken in facilities with immediate availability of appropriate resources, including equipment and personnel (obstetric anesthesia, nursing personnel, a clinician capable of monitoring labor and performing an emergency cesarean delivery, personnel and equipment for neonatal resuscitation) .
In situations in which such resources are not immediately available, ACOG recommends a discussion between the provider and patient to discuss implications of the lack of immediately available personnel. One antepartum option is referral to another facility with appropriate resources to obtain optimal outcomes. However, some doctors and patients may elect to proceed with TOLAC even if all desirable conditions cannot be met. In all cases, any decision to plan for TOLAC in a setting lacking immediately available resources should be made only after careful consideration by the woman and her health care provider. In such instances, the discussion and plan should be documented in the obstetrical record.
Intrapartum monitoring — Given an increased risk of uterine rupture, most experts recommend continuous monitoring of uterine activity and fetal heart rate during TOLAC; there are no data to show superiority of external versus internal monitoring methods . Intrauterine pressure monitoring is unnecessary, as it is an insensitive method for early diagnosis of uterine rupture [99,100].
Labor pattern — Labor progress between 4 and 7 cm in women with no previous vaginal births appears to be slightly longer than that in nulliparous women in spontaneous labor . Labor patterns in women who have delivered vaginally are similar to those in multigravidas .
Induction and augmentation of labor — Some women who plan TOLAC will develop a maternal or fetal indication for delivery before the onset of spontaneous labor. The benefits and harms of ERCD versus induction of labor have not been evaluated by randomized trials . While there is no conclusive evidence that uterotonic drugs administered to women with a prior cesarean delivery increase the risk of uterine rupture, epidemiological studies suggest that this is the case [34,104-106]. For this reason, we suggest a cautious approach to labor induction or augmentation in women planning/undergoing TOLAC, especially those with an unknown type of uterine scar, unfavorable cervix, or gestational age over 40 weeks [53,107,108]. ACOG considers both induction and augmentation reasonable options for TOLAC patients, when indicated .
●Induction – If the cervix is dilated and favorable, our preference is to perform amniotomy to induce labor in women with one previous cesarean delivery. A professional consensus opined against induction in women with two previous cesareans .
In a practice bulletin, ACOG recognized induction of labor with oxytocin or a mechanical method as options for women undergoing TOLAC . We agree with ACOG and others that misoprostol (prostaglandin E1) should not be used for cervical ripening or labor induction in the third trimester in women with prior uterine incisions and strongly discourage use of other prostaglandins as well [65,109-112].
Two concerns about inducing labor in women with a prior cesarean delivery are an increased risk for uterine rupture and a lower probability of successful TOLAC [113,114], according to data from observational studies. A prior vaginal delivery or favorable cervix (eg, Bishop score of >6) increases the probability of successful TOLAC with labor induction. Induction with oxytocin or mechanical methods appears to have a lower risk for uterine rupture than prostaglandins. These issues and supporting evidence are discussed in detail separately. (See "Cervical ripening and induction of labor in women with a prior cesarean delivery", section on 'Risk of rupture'.)
●Oxytocin augmentation – Women whose labors do not follow generally accepted standards of labor progress in the active phase are managed with oxytocin augmentation or repeat cesarean delivery, as appropriate. Despite a paucity of high-quality data, given the relative infrequency with which uterine rupture occurs, ACOG supports use of oxytocin for augmentation of labor in women with a previous cesarean delivery .
There are conflicting data on the risk of uterine rupture from oxytocin augmentation of labor during TOLAC. Three large observational studies reported an increased risk for uterine rupture with labor augmentation (odds ratio [OR] 2.3 to 14, actual rate of rupture 0.9 to 1.9 percent) [34,115,116], and two others did not find an increased risk [117,118]. Small numbers of uterine ruptures and use of prostaglandin analogues for cervical ripening prior to augmentation of labor prevent definitive conclusions based on these results.
It is unclear whether oxytocin regimens should be modified or an upper dose limit should be set in women undergoing TOLAC; this issue has not been evaluated extensively. A case-control study reported an increasing risk of uterine rupture with increasing oxytocin dose; the authors suggested an upper limit of 20 milliunits/min . Another study found the risk of rupture was primarily related to hyperstimulation . The low incidence of uterine rupture limits the power of these studies to detect small differences in dose-related risk of rupture.
Although clinicians generally have a lower threshold for diagnosing failure to progress in women undergoing TOLAC than in women with an unscarred uterus, evidence-based guidance does not exist. Based on expert consensus, the French College of Gynecologists and Obstetricians suggests that the total duration of failure to progress before performing cesarean delivery in the active phase should not exceed three hours for women with a previous cesarean .
Analgesia and anesthesia — Epidural analgesia may be used to provide adequate pain relief during labor . Epidural analgesia does not appear to mask the signs and symptoms of uterine rupture and/or reduce the chance of successful TOLAC . However, a prospective cohort study reported an increased risk of rupture in patients who had epidural anesthesia (OR 2.2, 95% CI 1.1-4.9) .
Amnioinfusion for management of variable decelerations — In women with an unscarred uterus and variable decelerations during labor, a systematic review of observational studies found that amnioinfusion was associated with a reduction in cesarean delivery and improvement in some neonatal outcomes . The risks of rare, but serious, adverse effects were not measurable.
There are even fewer data on amnioinfusion in women undergoing TOLAC [50,121-123]. Uterine ruptures have been reported in these patients [50,122,123], but it is unknown whether the rates of rupture and cesarean delivery are different from the rates in women undergoing TOLAC with variable decelerations not treated with amnioinfusion. Given the paucity of safety and efficacy data, the authors do not manage variable decelerations with amnioinfusion in women undergoing TOLAC.
Clinical findings, diagnosis, and management of uterine rupture — (See "Uterine rupture after previous cesarean delivery".)
Uterine exploration at delivery — Some clinicians recommend routine uterine exploration following uncomplicated successful TOLAC, while others only perform exploration for standard obstetrical indications, such as retained placenta or hemorrhage . There are no data on the value of routine examination to identify asymptomatic uterine dehiscence or whether repair is indicated, but the authors routinely perform uterine exploration following uncomplicated successful TOLAC. Identification of an asymptomatic uterine defect following vaginal delivery does not warrant immediate therapy. These patients are referred to the gynecology service postpartum for evaluation and possible treatment of isthmocele (ie, a pouch-like defect at the site of a previous cesarean delivery scar) .
RECOMMENDATIONS OF SELECTED NATIONAL ORGANIZATIONS — The following links, tables, and references provide recommendations from selected national organizations about appropriate candidates for TOLAC versus ERCD and management of these pregnancies.
SUMMARY AND RECOMMENDATIONS
●Pregnant women with a prior cesarean birth must choose between elective repeat cesarean delivery (ERCD) and a trial of labor after cesarean delivery (TOLAC). Obstetrical and personal factors impact this decision and should be discussed when counseling the patient (table 3). Her final decision will be based upon her individual clinical circumstances, tolerance for the various risks involved, personal values, and availability of a facility capable of emergency cesarean delivery if required. (See 'Shared decision-making' above.)
●Decision aids and calculators that predict probability of VBAC (vaginal birth after cesarean delivery) can help patients make a choice re: TOLAC versus repeat cesarean delivery. (See 'Decision aids' above and "Use of calculators and models for predicting vaginal birth after a previous cesarean delivery".)
●The medical and obstetric benefits of successful TOLAC derive from avoidance of the risks associated with repeat cesarean delivery, especially multiple cesarean deliveries: Most maternal morbidity associated with TOLAC occurs when intrapartum cesarean delivery becomes necessary. Conversely, the medical and obstetrical benefits of ERCD derive from avoidance of the risks associated with TOLAC, primarily uterine rupture. Thus, the benefits of TOLAC are closely related to having a successful vaginal birth, which has the lowest morbidity of the three possibilities. (See 'Overview' above.)
●The following table summarizes available evidence of maternal risks associated with TOLAC and ERCD (table 1). In a hypothetical group of 100,000 women at term who undergo TOLAC rather than ERCD, there will be 9 fewer maternal deaths, 650 additional uterine ruptures, and 50 additional neonatal deaths. Looked at in another way, these data suggest that approximately 1 in 200 TOLAC will lead to uterine rupture and approximately 1 in 750 TOLAC will result in perinatal death. (See 'Risks and benefits of TOLAC versus ERCD' above.)
●A woman with a singleton gestation who has undergone only one previous cesarean delivery performed using a transverse lower segment hysterotomy incision has the lowest risk of uterine scar separation during a subsequent trial of labor; thus, TOLAC is a reasonably safe option for delivery for these women. In this setting, TOLAC success rates are 60 to 80 percent, with an estimated uterine rupture rate of 0.4 to 0.7 percent. Success rates are higher in patients with additional characteristics, such as a previous successful TOLAC, previous vaginal delivery, previous cesarean delivery for nonvertex presentation, and in women with spontaneous onset of labor. (See 'Optimal candidates' above.)
●For women with a prior low vertical incision, more than one previous low transverse incision, unknown incision type, twin gestation, or macrosomia, the likelihood of TOLAC success and/or the risk of uterine is less favorable than for optimal candidates. After thorough counseling, some women may choose to attempt TOLAC. (See 'Possibly appropriate candidates' above.)
●Women with a previous classical, T, or J hysterotomy incision; uterine rupture; or extensive transfundal surgery are at high risk of uterine rupture and should avoid TOLAC. The woman should have no contraindications to vaginal delivery and the facility should be able to perform an emergency cesarean delivery, if required. (See 'Inappropriate candidates' above and 'Facilities and personnel' above.)
●Women who attempt TOLAC beyond 40 weeks of gestation are less likely to successfully deliver vaginally and may be at higher risk of uterine rupture. The authors discuss both of these issues with patients who are planning TOLAC and offer induction of labor by amniotomy at 40 weeks of gestation if the cervix is favorable. (See 'Pregnancy more than 40 weeks of gestation' above.)
●Observational data suggest that uterotonic drugs administered for induction or augmentation of labor increase the risk of uterine rupture in women with a prior cesarean delivery. For this reason, we suggest a cautious approach to labor induction or augmentation in women undergoing TOLAC, especially those with an unknown type of uterine scar, unfavorable cervix, or gestational age over 40 weeks. We agree with the American College of Obstetricians and Gynecologists and others that misoprostol (prostaglandin E1) should not be used for cervical ripening or labor induction in the third trimester in women with prior uterine incisions and strongly discourage use of other prostaglandins as well. We use amniotomy and/or oxytocin to induce labor and mechanical methods for cervical ripening. (See 'Induction and augmentation of labor' above.)
- Williams JW. Obstetrics: A Textbook for the Use of Students and Practitioners, 1st ed, D Appleton & Co, New York 1903.
- Cragin E. Conservatism in obstetrics. NY J Med 1916; 104:1.
- Kerr JM. The lower uterine segment incision in conservative caesarean section. BJOG 2005; 28:475.
- Eastman NJ. Williams Obstetrics, 10th ed, Appleton-Century-Crofts, New York 1950.
- Pauerstein CJ. Once a section, always a trial of labor? Obstet Gynecol 1966; 28:273.
- American College of Obstetricians and Gynecologists. New guidelines to reduce repeat cesareans. Statement by Dr. Luella Klein for VBAC News Conference, Washington, DC 1985.
- American College of Obstetricians and Gynecologists. Guidelines for vaginal delivery after previous cesarean birth. Committee Opinion No. 164. ACOG, Washington, DC 1988.
- Vaginal delivery after a previous cesarean birth. ACOG Committee opinion. Number 143-October 1994 (replaces No. 64, October 1988). Committee on Obstetric Practice. American College of Obstetricians and Gynecologists. Int J Gynaecol Obstet 1995; 48:127.
- Uddin SF, Simon AE. Rates and success rates of trial of labor after cesarean delivery in the United States, 1990-2009. Matern Child Health J 2013; 17:1309.
- Jones RO, Nagashima AW, Hartnett-Goodman MM, Goodlin RC. Rupture of low transverse cesarean scars during trial of labor. Obstet Gynecol 1991; 77:815.
- Scott JR. Mandatory trial of labor after cesarean delivery: an alternative viewpoint. Obstet Gynecol 1991; 77:811.
- Sach BP, Koblin C, Castro MA. The risk of lowering the cesarean-delivery rate. N Engl J Med 1999; 340:5.
- McMahon MJ, Luther ER, Bowes WA Jr, Olshan AF. Comparison of a trial of labor with an elective second cesarean section. N Engl J Med 1996; 335:689.
- Lydon-Rochelle M, Holt VL, Easterling TR, Martin DP. Risk of uterine rupture during labor among women with a prior cesarean delivery. N Engl J Med 2001; 345:3.
- American College of Obstetricians and Gynecologists. Vaginal delivery after previous cesarean delivery. Practice Bulletin No. 2. ACOG, Washington, DC 1998.
- American College of Obstetricians and Gynecologists. Vaginal delivery after previous cesarean section. Practice Bulletin No. 5. ACOG, Washington, DC 1999.
- American Society of Anesthesiologists Task Force on Obstetric Anesthesia. Practice guidelines for obstetric anesthesia: an updated report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia. Anesthesiology 2007; 106:843.
- American Society of Anesthesiologists. Optimal Goals For Anesthesia Care In Obstetrics-2008. ASA Standards, Guidelines and Statements. October 2007. http://www.asahq.org/~/media/legacy/for%20members/documents/standards%20guidelines%20stmts/opitmal%20goals%20anesthesia%20care%20obstetrics.pdf (Accessed on August 10, 2016).
- National Institutes of Health Consensus Development Conference Panel. National Institutes of Health Consensus Development conference statement: vaginal birth after cesarean: new insights March 8-10, 2010. Obstet Gynecol 2010; 115:1279.
- Shihady IR, Broussard P, Bolton LB, et al. Vaginal birth after cesarean: do California hospital policies follow national guidelines? J Reprod Med 2007; 52:349.
- Roberts RG, Deutchman M, King VJ, et al. Changing policies on vaginal birth after cesarean: impact on access. Birth 2007; 34:316.
- Guise JM, Eden K, Emeis C, et al. Vaginal birth after cesarean: new insights. Evid Rep Technol Assess (Full Rep) 2010; :1.
- Klagholz J, Strunk AL. American College of Obstetricians and Gynecologists. Overview of the 2009 ACOG survey on professional liability. https://www.acog.org/-/media/Departments/Professional-Liability/2012PLSurveyNational.pdf (Accessed on August 10, 2016).
- Clark SL, Belfort MA, Byrum SL, et al. Improved outcomes, fewer cesarean deliveries, and reduced litigation: results of a new paradigm in patient safety. Am J Obstet Gynecol 2008; 199:105.e1.
- Wells CE. Vaginal birth after cesarean delivery: views from the private practitioner. Semin Perinatol 2010; 34:345.
- Gilbert SA, Grobman WA, Landon MB, et al. Lifetime cost-effectiveness of trial of labor after cesarean in the United States. Value Health 2013; 16:953.
- Wymer KM, Shih YC, Plunkett BA. The cost-effectiveness of a trial of labor accrues with multiple subsequent vaginal deliveries. Am J Obstet Gynecol 2014; 211:56.e1.
- Dodd JM, Crowther CA, Huertas E, et al. Planned elective repeat caesarean section versus planned vaginal birth for women with a previous caesarean birth. Cochrane Database Syst Rev 2013; :CD004224.
- Guise JM, Denman MA, Emeis C, et al. Vaginal birth after cesarean: new insights on maternal and neonatal outcomes. Obstet Gynecol 2010; 115:1267.
- Wen SW, Huang L, Liston R, et al. Severe maternal morbidity in Canada, 1991-2001. CMAJ 2005; 173:759.
- Kaczmarczyk M, Sparén P, Terry P, Cnattingius S. Risk factors for uterine rupture and neonatal consequences of uterine rupture: a population-based study of successive pregnancies in Sweden. BJOG 2007; 114:1208.
- Spong CY, Landon MB, Gilbert S, et al. Risk of uterine rupture and adverse perinatal outcome at term after cesarean delivery. Obstet Gynecol 2007; 110:801.
- Holmgren C, Scott JR, Porter TF, et al. Uterine rupture with attempted vaginal birth after cesarean delivery: decision-to-delivery time and neonatal outcome. Obstet Gynecol 2012; 119:725.
- Landon MB, Hauth JC, Leveno KJ, et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery. N Engl J Med 2004; 351:2581.
- Sentilhes L, Vayssière C, Beucher G, et al. Delivery for women with a previous cesarean: guidelines for clinical practice from the French College of Gynecologists and Obstetricians (CNGOF). Eur J Obstet Gynecol Reprod Biol 2013; 170:25.
- Studsgaard A, Skorstengaard M, Glavind J, et al. Trial of labor compared to repeat cesarean section in women with no other risk factors than a prior cesarean delivery. Acta Obstet Gynecol Scand 2013; 92:1256.
- Fagerberg MC, Marsal K, Källen K. Neonatal outcome after trial of labor or elective cesarean section in relation to the indication for the previous cesarean delivery. Acta Obstet Gynecol Scand 2013; 92:1151.
- Bernstein SN, Matalon-Grazi S, Rosenn BM. Trial of labor versus repeat cesarean: are patients making an informed decision? Am J Obstet Gynecol 2012; 207:204.e1.
- Sharma PS, Eden KB, Guise JM, et al. Subjective risk vs. objective risk can lead to different post-cesarean birth decisions based on multiattribute modeling. J Clin Epidemiol 2011; 64:67.
- Lyerly AD, Mitchell LM, Armstrong EM, et al. Risks, values, and decision making surrounding pregnancy. Obstet Gynecol 2007; 109:979.
- Grunebaum A, Chervenak FA. Apgar Score of 0 and Seizure/Serious Neurologic Dysfunction in Home Births of Patients With Prior Cesarean Delivery . Obstet Gynecol 2016; 127 Suppl 1:1S.
- Cox KJ, Bovbjerg ML, Cheyney M, Leeman LM. Planned Home VBAC in the United States, 2004-2009: Outcomes, Maternity Care Practices, and Implications for Shared Decision Making. Birth 2015; 42:299.
- Horey D, Kealy M, Davey MA, et al. Interventions for supporting pregnant women's decision-making about mode of birth after a caesarean. Cochrane Database Syst Rev 2013; :CD010041.
- Grobman WA, Lai Y, Landon MB, et al. Development of a nomogram for prediction of vaginal birth after cesarean delivery. Obstet Gynecol 2007; 109:806.
- Metz TD, Stoddard GJ, Henry E, et al. Simple, validated vaginal birth after cesarean delivery prediction model for use at the time of admission. Obstet Gynecol 2013; 122:571.
- Chaillet N, Bujold E, Dubé E, Grobman WA. Validation of a prediction model for vaginal birth after caesarean. J Obstet Gynaecol Can 2013; 35:119.
- Schoorel EN, van Kuijk SM, Melman S, et al. Vaginal birth after a caesarean section: the development of a Western European population-based prediction model for deliveries at term. BJOG 2014; 121:194.
- Eden KB, McDonagh M, Denman MA, et al. New insights on vaginal birth after cesarean: can it be predicted? Obstet Gynecol 2010; 116:967.
- Sabol B, Denman MA, Guise JM. Vaginal birth after cesarean: an effective method to reduce cesarean. Clin Obstet Gynecol 2015; 58:309.
- Gimovsky ML, Bayer-Zwirello LA, Plevyak M. Fetal heart rate monitoring casebook. Amnioinfusion with uterine dehiscence and fetal distress. J Perinatol 1997; 17:83.
- Landon MB, Leindecker S, Spong CY, et al. The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean delivery. Am J Obstet Gynecol 2005; 193:1016.
- Zelop CM, Shipp TD, Repke JT, et al. Effect of previous vaginal delivery on the risk of uterine rupture during a subsequent trial of labor. Am J Obstet Gynecol 2000; 183:1184.
- Zelop CM, Shipp TD, Cohen A, et al. Trial of labor after 40 weeks' gestation in women with prior cesarean. Obstet Gynecol 2001; 97:391.
- Cameron CA, Roberts CL, Peat B. Predictors of labor and vaginal birth after cesarean section. Int J Gynaecol Obstet 2004; 85:267.
- King DE, Lahiri K. Socioeconomic factors and the odds of vaginal birth after cesarean delivery. JAMA 1994; 272:524.
- Srinivas SK, Stamilio DM, Stevens EJ, et al. Predicting failure of a vaginal birth attempt after cesarean delivery. Obstet Gynecol 2007; 109:800.
- Selo-Ojeme D, Abulhassan N, Mandal R, et al. Preferred and actual delivery mode after a cesarean in London, UK. Int J Gynaecol Obstet 2008; 102:156.
- Srinivas SK, Stamilio DM, Sammel MD, et al. Vaginal birth after caesarean delivery: does maternal age affect safety and success? Paediatr Perinat Epidemiol 2007; 21:114.
- Smith GC, White IR, Pell JP, Dobbie R. Predicting cesarean section and uterine rupture among women attempting vaginal birth after prior cesarean section. PLoS Med 2005; 2:e252.
- Gyamfi C, Juhasz G, Gyamfi P, Stone JL. Increased success of trial of labor after previous vaginal birth after cesarean. Obstet Gynecol 2004; 104:715.
- Kabir AA, Pridjian G, Steinmann WC, et al. Racial differences in cesareans: an analysis of U.S. 2001 National Inpatient Sample Data. Obstet Gynecol 2005; 105:710.
- DeFranco EA, Rampersad R, Atkins KL, et al. Do vaginal birth after cesarean outcomes differ based on hospital setting? Am J Obstet Gynecol 2007; 197:400.e1.
- Gregory KD, Korst LM, Cane P, et al. Vaginal birth after cesarean and uterine rupture rates in California. Obstet Gynecol 1999; 94:985.
- Tahseen S, Griffiths M. Vaginal birth after two caesarean sections (VBAC-2)-a systematic review with meta-analysis of success rate and adverse outcomes of VBAC-2 versus VBAC-1 and repeat (third) caesarean sections. BJOG 2010; 117:5.
- American College of Obstetricians and Gynecologists. ACOG Practice bulletin no. 115: Vaginal birth after previous cesarean delivery. Obstet Gynecol 2010; 116:450.
- Metz TD, Allshouse AA, Faucett AM, Grobman WA. Validation of a vaginal birth after cesarean delivery prediction model in women with two prior cesarean deliveries. Obstet Gynecol 2015; 125:948.
- Bretelle F, Cravello L, Shojai R, et al. Vaginal birth following two previous cesarean sections. Eur J Obstet Gynecol Reprod Biol 2001; 94:23.
- Macones GA, Cahill A, Pare E, et al. Obstetric outcomes in women with two prior cesarean deliveries: is vaginal birth after cesarean delivery a viable option? Am J Obstet Gynecol 2005; 192:1223.
- Smith D, Stringer E, Vladutiu CJ, et al. Risk of uterine rupture among women attempting vaginal birth after cesarean with an unknown uterine scar. Am J Obstet Gynecol 2015; 213:80.e1.
- Coassolo KM, Stamilio DM, Paré E, et al. Safety and efficacy of vaginal birth after cesarean attempts at or beyond 40 weeks of gestation. Obstet Gynecol 2005; 106:700.
- Kiran TS, Chui YK, Bethel J, Bhal PS. Is gestational age an independent variable affecting uterine scar rupture rates? Eur J Obstet Gynecol Reprod Biol 2006; 126:68.
- Hammoud A, Hendler I, Gauthier RJ, et al. The effect of gestational age on trial of labor after Cesarean section. J Matern Fetal Neonatal Med 2004; 15:202.
- Cahill A, Stamilio DM, Paré E, et al. Vaginal birth after cesarean (VBAC) attempt in twin pregnancies: is it safe? Am J Obstet Gynecol 2005; 193:1050.
- Aaronson D, Harlev A, Sheiner E, Levy A. Trial of labor after cesarean section in twin pregnancies: maternal and neonatal safety. J Matern Fetal Neonatal Med 2010; 23:550.
- Varner MW, Leindecker S, Spong CY, et al. The Maternal-Fetal Medicine Unit cesarean registry: trial of labor with a twin gestation. Am J Obstet Gynecol 2005; 193:135.
- Committee on Practice Bulletins—Obstetrics, Society for Maternal–Fetal Medicine. Practice Bulletin No. 169: Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies. Obstet Gynecol 2016; 128:e131.
- American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Obstetrics. Practice Bulletin No. 173: Fetal Macrosomia. Obstet Gynecol 2016; 128:e195.
- Elkousy MA, Sammel M, Stevens E, et al. The effect of birth weight on vaginal birth after cesarean delivery success rates. Am J Obstet Gynecol 2003; 188:824.
- Flamm BL, Goings JR. Vaginal birth after cesarean section: is suspected fetal macrosomia a contraindication? Obstet Gynecol 1989; 74:694.
- Zelop CM, Shipp TD, Repke JT, et al. Outcomes of trial of labor following previous cesarean delivery among women with fetuses weighing >4000 g. Am J Obstet Gynecol 2001; 185:903.
- Jastrow N, Roberge S, Gauthier RJ, et al. Effect of birth weight on adverse obstetric outcomes in vaginal birth after cesarean delivery. Obstet Gynecol 2010; 115:338.
- Blackwell SC, Hassan SS, Wolfe HM, et al. Vaginal birth after cesarean in the diabetic gravida. J Reprod Med 2000; 45:987.
- Dharan VB, Srinivas SK, Parry S, et al. Pregestational diabetes: a risk factor for vaginal birth after cesarean section failure? Am J Perinatol 2010; 27:265.
- Regan J, Keup C, Wolfe K, et al. Vaginal birth after cesarean success in high-risk women: a population-based study. J Perinatol 2015; 35:252.
- Hibbard JU, Gilbert S, Landon MB, et al. Trial of labor or repeat cesarean delivery in women with morbid obesity and previous cesarean delivery. Obstet Gynecol 2006; 108:125.
- Chauhan SP, Magann EF, Carroll CS, et al. Mode of delivery for the morbidly obese with prior cesarean delivery: vaginal versus repeat cesarean section. Am J Obstet Gynecol 2001; 185:349.
- Carroll CS Sr, Magann EF, Chauhan SP, et al. Vaginal birth after cesarean section versus elective repeat cesarean delivery: Weight-based outcomes. Am J Obstet Gynecol 2003; 188:1516.
- Bujold E, Hammoud A, Schild C, et al. The role of maternal body mass index in outcomes of vaginal births after cesarean. Am J Obstet Gynecol 2005; 193:1517.
- Durnwald CP, Ehrenberg HM, Mercer BM. The impact of maternal obesity and weight gain on vaginal birth after cesarean section success. Am J Obstet Gynecol 2004; 191:954.
- Goldfarb I, Henry D, Dumont O. Inadvertant hysterotomy extension at cesarean delivery and risk of uterine rupture in the next pregnancy. Am J Obstet Gynecol 2011; 204:S266.
- Ritchie EH. Pregnancy after rupture of the pregnant uterus. A report of 36 pregnancies and a study of cases reported since 1932. J Obstet Gynaecol Br Commonw 1971; 78:642.
- Reyes-Ceja L, Cabrera R, Insfran E, Herrera-Lasso F. Pregnancy following previous uterine rupture. Study of 19 patients. Obstet Gynecol 1969; 34:387.
- Sajjad Y, Sharma SD, Thomas K. Three consecutive uterine ruptures in the same woman, each with fetal survival. BJOG 2005; 112:1005.
- Chibber R, El-Saleh E, Al Fadhli R, et al. Uterine rupture and subsequent pregnancy outcome--how safe is it? A 25-year study. J Matern Fetal Neonatal Med 2010; 23:421.
- Soltan MH, Khashoggi T, Adelusi B. Pregnancy following rupture of the pregnant uterus. Int J Gynaecol Obstet 1996; 52:37.
- Wilson RD, Lemerand K, Johnson MP, et al. Reproductive outcomes in subsequent pregnancies after a pregnancy complicated by open maternal-fetal surgery (1996-2007). Am J Obstet Gynecol 2010; 203:209.e1.
- Klemm P, Koehler C, Mangler M, et al. Laparoscopic and vaginal repair of uterine scar dehiscence following cesarean section as detected by ultrasound. J Perinat Med 2005; 33:324.
- Donnez O, Jadoul P, Squifflet J, Donnez J. Laparoscopic repair of wide and deep uterine scar dehiscence after cesarean section. Fertil Steril 2008; 89:974.
- Devoe LD, Croom CS, Youssef AA, Murray C. The prediction of "controlled" uterine rupture by the use of intrauterine pressure catheters. Obstet Gynecol 1992; 80:626.
- Rodriguez MH, Masaki DI, Phelan JP, Diaz FG. Uterine rupture: are intrauterine pressure catheters useful in the diagnosis? Am J Obstet Gynecol 1989; 161:666.
- Grantz KL, Gonzalez-Quintero V, Troendle J, et al. Labor patterns in women attempting vaginal birth after cesarean with normal neonatal outcomes. Am J Obstet Gynecol 2015; 213:226.e1.
- Chazotte C, Madden R, Cohen WR. Labor patterns in women with previous cesareans. Obstet Gynecol 1990; 75:350.
- Dodd JM, Crowther CA, Grivell RM, Deussen AR. Elective repeat caesarean section versus induction of labour for women with a previous caesarean birth. Cochrane Database Syst Rev 2014; :CD004906.
- Cahill AG, Waterman BM, Stamilio DM, et al. Higher maximum doses of oxytocin are associated with an unacceptably high risk for uterine rupture in patients attempting vaginal birth after cesarean delivery. Am J Obstet Gynecol 2008; 199:32.e1.
- Goetzl L, Shipp TD, Cohen A, et al. Oxytocin dose and the risk of uterine rupture in trial of labor after cesarean. Obstet Gynecol 2001; 97:381.
- Cahill AG, Stamilio DM, Odibo AO, et al. Does a maximum dose of oxytocin affect risk for uterine rupture in candidates for vaginal birth after cesarean delivery? Am J Obstet Gynecol 2007; 197:495.e1.
- Hickman MA. The MFMU cesarean registry: Risk of uterine rupture in women attempting VBAC with an unknown uterine scar. Am J Obstet Gynecol 2008; 199:S36.
- Grubb DK, Kjos SL, Paul RH. Latent labor with an unknown uterine scar. Obstet Gynecol 1996; 88:351.
- Bennett BB. Uterine rupture during induction of labor at term with intravaginal misoprostol. Obstet Gynecol 1997; 89:832.
- Wing DA, Lovett K, Paul RH. Disruption of prior uterine incision following misoprostol for labor induction in women with previous cesarean delivery. Obstet Gynecol 1998; 91:828.
- Plaut MM, Schwartz ML, Lubarsky SL. Uterine rupture associated with the use of misoprostol in the gravid patient with a previous cesarean section. Am J Obstet Gynecol 1999; 180:1535.
- Aslan H, Unlu E, Agar M, Ceylan Y. Uterine rupture associated with misoprostol labor induction in women with previous cesarean delivery. Eur J Obstet Gynecol Reprod Biol 2004; 113:45.
- Lappen JR, Hackney DN, Bailit JL. Outcomes of Term Induction in Trial of Labor After Cesarean Delivery: Analysis of a Modern Obstetric Cohort. Obstet Gynecol 2015; 126:115.
- Al-Shaikh G, Al-Mandeel H. The outcomes of trial of labour after cesarean section following induction of labour compared to spontaneous labour. Arch Gynecol Obstet 2013; 287:1099.
- Zelop CM, Shipp TD, Repke JT, et al. Uterine rupture during induced or augmented labor in gravid women with one prior cesarean delivery. Am J Obstet Gynecol 1999; 181:882.
- Dekker GA, Chan A, Luke CG, et al. Risk of uterine rupture in Australian women attempting vaginal birth after one prior caesarean section: a retrospective population-based cohort study. BJOG 2010; 117:1358.
- Macones GA, Peipert J, Nelson DB, et al. Maternal complications with vaginal birth after cesarean delivery: a multicenter study. Am J Obstet Gynecol 2005; 193:1656.
- Flamm BL, Goings JR, Fuelberth NJ, et al. Oxytocin during labor after previous cesarean section: results of a multicenter study. Obstet Gynecol 1987; 70:709.
- Sakala EP, Kaye S, Murray RD, Munson LJ. Epidural analgesia. Effect on the likelihood of a successful trial of labor after cesarean section. J Reprod Med 1990; 35:886.
- Hofmeyr GJ, Lawrie TA. Amnioinfusion for potential or suspected umbilical cord compression in labour. Cochrane Database Syst Rev 2012; 1:CD000013.
- Strong TH Jr, Vega JS, O'Shaughnessy MJ, et al. Amnioinfusion among women attempting vaginal birth after cesarean delivery. Obstet Gynecol 1992; 79:673.
- Ouzounian JG, Miller DA, Paul RH. Amnioinfusion in women with previous cesarean births: a preliminary report. Am J Obstet Gynecol 1996; 174:783.
- Adair CD, Sanchez-Ramos L, Kaunitz AM, Briones D. A trial of labor complicated by uterine rupture following amnioinfusion. South Med J 1995; 88:847.
- Lurie S, Hagay Z, Goldschmit R, Insler V. Routine previous cesarean scar exploration following successful vaginal delivery. Is it necessary? Eur J Obstet Gynecol Reprod Biol 1992; 45:185.
- Tulandi T, Cohen A. Emerging Manifestations of Cesarean Scar Defect in Reproductive-aged Women. J Minim Invasive Gynecol 2016; 23:893.