Twin delivery after a previous caesarean: a twelve-year experience

Trial of labor after cesarean, vaginal birth after cesarean, and the risk of uterine rupture: an expert review

The decision to pursue a trial of labor after cesarean delivery is complex and depends on patient preference, the likelihood of successful vaginal birth after cesarean delivery, assessment of the risks vs benefits of trial of labor after cesarean delivery, and available resources to support safe trial of labor after cesarean delivery at the planned birthing center. The most feared complication of trial of labor after cesarean delivery is uterine rupture, which can have catastrophic consequences, including substantial maternal and perinatal morbidity and mortality. Although the absolute risk of uterine rupture is low, several clinical, historical, obstetrical, and intrapartum factors have been associated with increased risk. It is therefore critical for clinicians managing patients during trial of labor after cesarean delivery to be aware of these risk factors to appropriately select candidates for trial of labor after cesarean delivery and maximize the safety and benefits while minimizing the risks. Caution is advised when considering labor augmentation and induction in patients with a previous cesarean delivery. With established hospital safety protocols that dictate close maternal and fetal monitoring, avoidance of prostaglandins, and careful titration of oxytocin infusion when induction agents are needed, spontaneous and induced trial of labor after cesarean delivery are safe and should be offered to most patients with 1 previous low transverse, low vertical, or unknown uterine incision after appropriate evaluation, counseling, planning, and shared decision-making. Future research should focus on clarifying true risk factors and identifying the optimal approach to intrapartum and induction management, tools for antenatal prediction, and strategies for prevention of uterine rupture during trial of labor after cesarean delivery. A better understanding will facilitate patient counseling, support efforts to improve trial of labor after cesarean delivery and vaginal birth after cesarean delivery rates, and reduce the morbidity and mortality associated with uterine rupture during trial of labor after cesarean delivery.

Factors affecting elective cesarean section in women with multiple pregnancy in Caruban, Indonesia

Background: Caesarean sections have become the most popular method for delivering twin babies because of the safety concerns associated with a natural birth. This study aims to identify the maternal characteristics and obstetric parameters that serve as risk factors influencing caesarean delivery in twin pregnancies by comparing women delivering via caesarean section and vaginal birth. Methods: A retrospective chart review design was used to analyse 47 women with multiple pregnancies from the medical records at a primary referral hospital in East Java, Indonesia. Women delivering vaginally were then compared with women who underwent a caesarean section to identify any differences between the groups. Results: In our study, more women delivered by caesarean section (n=35) than by vaginal birth (n=12). Women were more likely to undergo a caesarean section if they had a previous history of undergoing a caesarean section (OR 16.5; 95% CI 1.91-142.49; p=0.02). Similar to previous studies, we found that foetal malpresentation significantly increase the risk of caesarean delivery (OR 8.25; 95%CI 0.95-71.09; p=0.03), while labour augmentation decrease the likelihood of caesarean section (OR 0.20; 95% CI 0.49-0.81; p=0.03). There was also a significant older patients in the caesarean section groups (OR 1.26; 95% CI 1.09-1.45 ; p=0.00). Conclusions: The percentage of multiple pregnancies delivered via caesarean section is quite high. Other larger cohort study are warranted, since many factors were involved in the decision of caesarean section.

Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies: ACOG Practice Bulletin, Number 231

The incidence of multifetal gestations in the United States has increased dramatically over the past several decades. For example, the rate of twin births increased 76% between 1980 and 2009, from 18.9 to 33.3 per 1,000 births (1). However, after more than three decades of increases, the twin birth rate declined 4% during 2014-2018 to 32.6 twins per 1,000 total births in 2018 (2). The rate of triplet and higher-order multifetal gestations increased more than 400% during the 1980s and 1990s, peaking at 193.5 per 100,000 births in 1998, followed by a modest decrease to 153.4 per 100,000 births by 2009 (3). The triplet and higher-order multiple birth rate was 93.0 per 100,000 births for 2018, an 8% decline from 2017 (101.6) and a 52% decline from the 1998 peak (193.5) (4). The long-term changes in the incidence of multifetal gestations has been attributed to two main factors: 1) a shift toward an older maternal age at conception, when multifetal gestations are more likely to occur naturally, and 2) an increased use of assisted reproductive technology (ART), which is more likely to result in a multifetal gestation (5). A number of perinatal complications are increased with multiple gestations, including fetal anomalies, preeclampsia, and gestational diabetes. One of the most consequential complications encountered with multifetal gestations is preterm birth and the resultant infant morbidity and mortality. Although multiple interventions have been evaluated in the hope of prolonging these gestations and improving outcomes, none has had a substantial effect. The purpose of this document is to review the issues and complications associated with twin, triplet, and higher-order multifetal gestations and present an evidence-based approach to management.

Twin TOLAC is an independent risk factor for adverse maternal and neonatal outcome

PURPOSE

To determine factors associated with a successful twin trial of labor after Cesarean delivery (TOLAC).

METHODS

A retrospective cohort study was conducted at a single medical center in a population highly motivated for TOLAC (> 80%). The effect of maternal demographic and obstetric characteristics on the likelihood of twin TOLAC success was analyzed. Maternal complications and combined adverse outcome (uterine rupture, Apgar < 7 at 5 min, and umbilical cord pH < 7.1) were compared between singleton and twin TOLAC groups.

RESULTS

Ninety-five women with a twin gestation and one previous Cesarean delivery comprised the study group. Five thousand seven hundred and three women with a singleton gestation and one previous Cesarean delivery comprised the control group. 30.5% and 83% of women with twin and singleton gestation, respectively, underwent a trial of labor. Women in the twin TOLAC group were significantly less likely to succeed and less likely to have a spontaneous unassisted vaginal delivery compared to women in the singleton TOLAC group. Maternal age less than 35 years, parity greater than two, and at least one previous VBAC increased the likelihood of TOLAC success. Statistically significant differences were found between the twin TOLAC and the singleton TOLAC group for uterine rupture, maternal complications, and for combined adverse outcome.

CONCLUSIONS

Twin TOLAC is not common, even in parturients highly motivated for TOLAC. Our results demonstrate that even in a selected population, women undergoing twin TOLAC are less likely to have a successful spontaneous vaginal delivery and have a higher risk for uterine rupture, maternal complications, and combined adverse perinatal outcome than women undergoing TOLAC with a singleton gestation. Demographic and obstetric risk factors were identified which can aid the attending obstetrician in the counseling of these challenging cases.

Risk of Uterine Rupture with Vaginal Birth after Cesarean in Twin Gestations

BACKGROUND

Women with a previous cesarean delivery may attempt a subsequent vaginal birth or repeat cesarean. Vaginal birth after cesarean carries a greater risk of uterine rupture, defined as the disruption of all uterine layers, resulting in maternal-fetal morbidity or mortality. It is unclear how the risk of uterine rupture compares in patients with twin gestations who undergo different delivery methods.

OBJECTIVE

The purpose of this systematic review is to determine if there is an increased risk of uterine rupture in patients with twin gestations attempting vaginal birth after cesarean (VBAC) versus planned repeat cesarean delivery (PRCD). Study Design. PubMed, Cochrane Library, and CINAHL were searched systematically. Eligible studies were prospective and retrospective studies that evaluated the incidence of uterine rupture in twin pregnancies that attempted VBAC or PRCD. Data were manually extracted from these studies, and the number of events in each group was used to calculate an odds ratio (OR) and 95% confidence interval (CI).

RESULTS

4 retrospective studies were included with a total of 7699 participants, 2305 of whom attempted VBAC and 5394 underwent PRCD. The absolute risk of uterine rupture in the VBAC and PRCD groups was 0.87% and 0.09%, respectively. The rate of uterine rupture was significantly higher in the VBAC group than in the PRCD group (OR: 9.43; CI: 3.54-25.17).

CONCLUSION

Although VBAC is associated with higher rates of uterine rupture in twin pregnancies when compared with PRCD, the absolute risk of uterine rupture is low in both groups. Depending on individual risk factors, vaginal birth may be offered as a safe option to women with twin pregnancies and a history of cesarean delivery.

No. 382-Trial of Labour After Caesarean

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour after Caesarean section.

OUTCOMES

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to October 31, 2017 using the key words "vaginal birth after Caesarean (Cesarean) section." The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

VALIDATION

These guidelines were approved by the Clinical Practice Obstetrics Committee and the Board of the Society of Obstetricians and Gynaecologists of Canada.

RECOMMENDATIONS

Trial of labor versus elective repeat cesarean delivery in twin pregnancies after a previous cesarean delivery-A systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of success rates of trial of labor after cesarean (TOLAC) and maternal and neonatal outcomes in twin pregnancy versus elective repeat cesarean delivery (ERCD).

METHODS

We searched MEDLINE, EMBASE, and Web of Science from data inception to May 2018 with no language or regional restrictions, to identify all studies that compared twin TOLAC and ERCD for maternal and/or neonatal outcomes. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. We assessed the pooled relative risk and mean difference using a random-effects model. The pooled event rates for successful VBAC, cesarean delivery for twin B after vaginal delivery of twin A, and uterine rupture were determined.

RESULTS

Of the 841 citations identified, 10 were eligible for analysis (2336 TOLAC cases and 5763 ERCD cases). The pooled event rates for successful VBAC and uterine rupture during TOLAC were 72.2% (95% CI 59.7%-83.2%) and 0.87% (95% CI 0.51%-1.31%), respectively. TOLAC was associated with a significantly higher risk of neonatal death (RR 3.02 [95% CI 1.07-8.54]) with no significant differences in mean gestational age at birth, NICU admission rates, or 5-minute Apgar <7. Although the risk for maternal infectious morbidity was significantly lower with TOLAC (RR 0.48 [95% CI 0.25-0.90]), risks of uterine dehiscence, blood transfusions, and hysterectomy were comparable.

CONCLUSIONS

Twin TOLAC is associated with a relatively high rate of successful vaginal delivery and a low risk of uterine rupture. The finding of higher neonatal mortality rates may be influenced by prematurity, but requires further investigation.

ACOG Practice Bulletin No. 205: Vaginal Birth After Cesarean Delivery

Trial of labor after cesarean delivery (TOLAC) refers to a planned attempt to deliver vaginally by a woman who has had a previous cesarean delivery, regardless of the outcome. This method provides women who desire a vaginal delivery the possibility of achieving that goal-a vaginal birth after cesarean delivery (VBAC). In addition to fulfilling a patient's preference for vaginal delivery, at an individual level, VBAC is associated with decreased maternal morbidity and a decreased risk of complications in future pregnancies as well as a decrease in the overall cesarean delivery rate at the population level (). However, although TOLAC is appropriate for many women, several factors increase the likelihood of a failed trial of labor, which in turn is associated with increased maternal and perinatal morbidity when compared with a successful trial of labor (ie, VBAC) and elective repeat cesarean delivery (). Therefore, assessing the likelihood of VBAC as well as the individual risks is important when determining who is an appropriate candidate for TOLAC. Thus, the purpose of this document is to review the risks and benefits of TOLAC in various clinical situations and to provide practical guidelines for counseling and management of patients who will attempt to give birth vaginally after a previous cesarean delivery.

No. 155-Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section." The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

VALIDATION: These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.

Trial of labor after cesarean delivery in twin gestations: systematic review and meta-analysis

BACKGROUND

Trial of labor after cesarean is offered as a routine option for singleton gestations with previous cesarean delivery. However, adequate data are not available to determine whether the approach is equally valid in women with twin gestation.

OBJECTIVE

This systematic review and meta-analysis aimed to assess maternal morbidities associated with trial of labor after cesarean delivery in twin gestations.

STUDY DESIGN

Electronic databases were searched for cohort studies and randomized controlled trials evaluating the association between trial of labor after cesarean delivery in twin gestations and pregnancy outcomes. Maternal mortality and severe morbidities, such as uterine rupture and hysterectomy, were compared between women who had trial of labor and women who had a planned repeat cesarean delivery. Pooled odds ratios were calculated using a random-effects model. Additional analyses were performed to compare trial of labor after cesarean outcomes in singleton and twin gestations.

RESULTS

Eleven cohort studies including a total of 8209 twin gestations with previous cesarean delivery were included in the present study. Of these gestations, 2484 were intended for planned vaginal birth and 5725 were intended for planned repeat cesarean delivery. The rate of uterine rupture in twin gestations was higher in the trial of labor after cesarean group than the elective cesarean group (odds ratio, 10.09, 95% confidence interval, 4.30-23.69, I² = 68%). However, no statistically significant difference was found in the rate of uterine rupture between twin and single gestations attempting trial of labor after cesarean delivery (odds ratio, 1.34, 95% confidence interval, 0.54-3.31, I² = 0%). Women who attempted a trial of labor after cesarean delivery with twins did not have an increased risk of uterine scar dehiscence, hemorrhage, blood transfusion, or neonatal morbidity and mortality compared with elective repeat cesarean delivery. Patients with twins had similar rates of successful vaginal delivery as patients with singletons (odds ratio, 0.85, 95% confidence interval, 0.61-1.18, I² = 36%).

CONCLUSION

This meta-analysis demonstrates that, although trial of labor with twins after previous cesarean delivery is associated with higher rates of uterine rupture compared with elective cesarean delivery, pregnancy outcomes and success rates are similar to a trial of labor after previous cesarean delivery in singleton gestations. Planned vaginal birth for women with twin gestation and previous cesarean delivery may be a safe alternative to a planned repeat cesarean.

Practice Bulletin No. 184: Vaginal Birth After Cesarean Delivery

Trial of labor after cesarean delivery (TOLAC) refers to a planned attempt to deliver vaginally by a woman who has had a previous cesarean delivery, regardless of the outcome. This method provides women who desire a vaginal delivery the possibility of achieving that goal-a vaginal birth after cesarean delivery (VBAC). In addition to fulfilling a patient's preference for vaginal delivery, at an individual level, VBAC is associated with decreased maternal morbidity and a decreased risk of complications in future pregnancies as well as a decrease in the overall cesarean delivery rate at the population level (1-3). However, although TOLAC is appropriate for many women, several factors increase the likelihood of a failed trial of labor, which in turn is associated with increased maternal and perinatal morbidity when compared with a successful trial of labor (ie, VBAC) and elective repeat cesarean delivery (4-6). Therefore, assessing the likelihood of VBAC as well as the individual risks is important when determining who is an appropriate candidate for TOLAC. Thus, the purpose of this document is to review the risks and benefits of TOLAC in various clinical situations and to provide practical guidelines for counseling and management of patients who will attempt to give birth vaginally after a previous cesarean delivery.

Trial of labor after cesarean section in twin pregnancies: maternal and neonatal safety

OBJECTIVE

To assess maternal and perinatal morbidity in patients undergoing a trial of labor after cesarean section (TOLAC) in twin gestations.

METHODS

A retrospective study including all twin pregnancies with a single prior cesarean section was performed. Stratified analysis using a multiple logistic regression model was performed to control for confounders. Patients who had a clear medical indication for a cesarean section (i.e. previous corporeal cesarean section, breech or transverse presentation, placenta previa, placental abruption, and herpes infection) were excluded from the analysis.

RESULTS

During the years 1988-2007, 134 patients met the inclusion criteria. Of these, 25 patients underwent a trial of labor and the remaining 109 underwent a repeat cesarean delivery. There were no cases of uterine rupture, maternal mortality, or peripartum fever in our population. Higher rates of perinatal mortality were noted in patients undergoing a trial of labor (8% vs. 1.8%, p = 0.042, OR = 4.652, 95% CI = 1.122-19.286). However, a trial of labor was not found to be an independent risk factor for perinatal mortality after controlling for confounders such as gestational age, ethnicity, and fetal malformations (adjusted OR = 1.07, 95% CI = 0.07-15.95, p = 0.95).

CONCLUSIONS

A TOLAC is not associated with an increased risk for maternal morbidity, including uterine rupture. Nevertheless, in our population TOLAC was noted as a risk factor for perinatal mortality, although residual confounding cannot be excluded. Further prospective randomized studies should evaluate the safety of TOLAC in twin gestations to establish appropriate guidelines.

Vaginal birth after cesarean delivery in twin gestations: a large, nationwide sample of deliveries

OBJECTIVE

The purpose of this study was to assess the maternal morbidity associated with attempted vaginal birth after cesarean (VBAC) in twin gestations using a large, nationwide sample of deliveries.

STUDY DESIGN

Data for this study were obtained from an administrative dataset, the Nationwide Inpatient Sample, a representative sample of discharges from non-Federal hospitals, for the years 1993 to 2002. Patients admitted nonemergently for the delivery of twin gestations who had a history of previous cesarean delivery were selected. Patients that either delivered vaginally or who had discharge codes that indicated labor before cesarean delivery were defined as the trial of labor group, while patients who had a cesarean delivery without discharge codes that indicated labor were defined as the elective cesarean group. Various complications of delivery were analyzed for each group.

RESULTS

We identified 4705 women who underwent an elective cesarean delivery and 1850 women who underwent a trial of labor. For women who had a trial of labor, 836 (45.2%) delivered vaginally. The rate of uterine rupture was higher in the trial of labor group than in the elective cesarean group (0.9% vs 0.1%, P < .001), and the rate of wound complications was lower (0.6% vs 1.3%, P < .02). The rates of other complications including hysterectomy, transfusion, major postpartum infection, thromboembolism, uterine dehiscence, and pelvic hematoma were not significantly different between the 2 groups.

CONCLUSION

Our study showed a significantly higher rate of uterine rupture in the trial of labor group that is similar to the rates reported for trial of labor after cesarean in singleton pregnancies.

Essai de travail en cas de césarienne antérieure

OBJECTIVE

The aim of this review was to relate the evolution of obstetrical management of delivery in women who had previously undergone cesarean delivery and to search the studies supporting the choice of the mode of delivery.

MATERIAL AND METHOD

We identified relevant studies through a computer search in the Medline database.

RESULTS

After a period from 1980 to 2000 when the vaginal delivery had been increasingly recommended, a growth in the use of the planned cesarean delivery was observed. Recent studies report more evidence that uterine rupture is the result of trial of labor and that adverse perinatal outcomes are associated with uterine rupture. The risk of uterine rupture is increased with labor induction. The use of prostaglandins appears to be implicated in a significant increase of uterine rupture, and subsequently might be contraindicated in this situation. The use of oxytocin induced labor appears to increase the risk of uterine rupture. However, the level of adverse perinatal outcomes is low. The choice of the mode of delivery should take into account the likelihood of a further pregnancy, due to the increased risk of placental pathologic conditions depending on the number of repeated cesarean sections.

CONCLUSION

An optimal decision for the mode of delivery should be shared with the pregnant women and all these factors should be taken into consideration.

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

OBJECTIVE

The purpose of this study was to compare the rate of vaginal birth after cesarean (VBAC) attempt, VBAC failure, and major maternal adverse outcomes in women with a previous cesarean with twin or singleton pregnancies.

STUDY DESIGN

This was a multicenter retrospective cohort study between the years 1996 and 2000. Subjects were identified by ICD-9 code. Trained research nurses collected medical record data on the outcome of VBAC attempts, and clinical outcomes, including uterine rupture and major operative injuries. We used bivariate and multivariable techniques to assess the association between twins and the outcomes.

RESULTS

Of 25,005 patients with at least 1 previous cesarean, there were 535 twin pregnancies and 24,307 singleton pregnancies. Compared with patients with singleton gestations, patients with twins were less likely to attempt a VBAC (adjusted odds ratio [AOR] 0.3, 95% CI 0.2-0.4), but no more likely to have a VBAC failure (AOR 1.1, 95% CI 0.8-1.6), a uterine rupture (AOR 1.2, 95% CI 0.3-4.6), or a major maternal morbidity (AOR 1.6, 95% CI 0.7-3.7).

CONCLUSION

Women with twin gestations are less likely to attempt a VBAC, but they are no more likely to fail a VBAC trial or experience a major morbid event compared with women with singleton gestations.

The Maternal-Fetal Medicine Unit cesarean registry: trial of labor with a twin gestation

OBJECTIVE

The purpose of this study was to identify the success rates and risks in women with a twin pregnancy who attempt a trial of labor after cesarean delivery.

STUDY DESIGN

Cases were identified in the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network's Cesarean Registry with a woman with a twin pregnancy who had had at least 1 previous cesarean delivery.

RESULTS

During the study period (1999-2002), 412 women fulfilled the study criteria, and 226 women had elective repeat cesarean delivery. Of the 186 women (45.1% of total) who attempted a trial of labor, 120 women were delivered successfully (success rate, 64.5%), and 66 women (35.5%) had a failed trial of labor. Thirty of the failed trials of labor involved a vaginal delivery for twin A and cesarean delivery for twin B. Women who attempted a trial of labor with twins had no increased risk of transfusion, endometritis, intensive care unit admissions, or uterine rupture when compared with elective repeat cesarean delivery. Fetal and neonatal complications were uncommon in either group at>or=34 weeks of gestation.

CONCLUSION

A trial of labor with twins after previous cesarean delivery does not appear to increase maternal morbidity. Perinatal morbidity is uncommon at>or=34 weeks of gestation.

Intrapartum management of twins: truths and controversies

Twin gestations pose a challenge in management, and the intrapartum phase of care is not exempt. Despite increasing numbers of twin gestations, the literature does not adequately answer several basic questions regarding appropriate intrapartum management. This article provides an overview of the available literature supporting appropriate intrapartum actions in twin gestations and highlights areas that are still awaiting further study, with the eventual goal of optimizing intrapartum conditions, leading to an improved neonatal outcome.

Evidence-based vaginal birth after Caesarean section

Caesarean section rates are rising globally. Whether vaginal birth after Caesarean (VBAC) is safe and under what circumstances is increasingly important. This chapter reviews the literature about the risks of VBAC, patient and management factors that may alter risk, and discusses ongoing research as well as suggestions for improving future research.

Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section". The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

1. Provided there are no contraindications, a woman with 1 previous transverse low-segment Caesarean section should be offered a trial of labour (TOL) with appropriate discussion of perinatal risks and benefits. The process of informed consent with appropriate documentation should be an important part of the birth plan in a woman with a previous Caesarean section (II-2B). 2. The intention of a woman undergoing a TOL after Caesarean section should be clearly stated, and documentation of the previous uterine scar should be clearly marked on the prenatal record (II-2B). 3. For a safe labour after Caesarean section, a woman should deliver in a hospital where a timely Caesarean section is possible. The woman and her health care provider must be aware of the hospital resources and the availability of obstetric, anesthetic, pediatric, and operating-room staff (II-2A). 4. Each hospital should have a written policy in place regarding the notification and (or) consultation for the physicians responsible for a possible timely Caesarean section (III-B). 5. In the case of a TOL after Caesarean, an approximate time frame of 30 minutes should be considered adequate in the set-up of an urgent laparotomy (III-C). 6. Continuous electronic monitoring of women attempting a TOL after Caesarean section is recommended (II-2A). 7. Suspected uterine rupture requires urgent attention and expedited laparotomy to attempt to decrease maternal and perinatal morbidity and mortality (II-2A). 8. Oxytocin augmentation is not contraindicated in women undergoing a TOL after Caesarean section (11-2A). 9. Medical induction of labour with oxytocin may be associated with an increased risk of uterine rupture and should be used carefully after appropriate counselling (II-2B). 10. Medical induction of labour with prostaglandin E2 (dinoprostone) is associated with an increased risk of uterine rupture and should not be used except in rare circumstances and after appropriate counselling (II-2B). 11. Prostaglandin E1 (misoprostol) is associated with a high risk of uterine rupture and should not be used as part of a TOL after Caesarean section (II-2A). 12. A foley catheter may be safely used to ripen the cervix in a woman planning a TOL after Caesarean section (II-2A). 13. The available data suggest that a trial of labour in women with more than 1 previous Caesarean section is likely to be successful but is associated with a higher risk of uterine rupture (II-2B). 14. Multiple gestation is not a contraindication to TOL after Caesarean section (II-2B). 15. Diabetes mellitus is not a contraindication to TOL after Caesarean section (II-2B). 16. Suspected fetal macrosomia is not a contraindication to TOL after Caesarean section (II-2B). 17. Women delivering within 18 to 24 months of a Caesarean section should be counselled about an increased risk of uterine rupture in labour (II-2B). 18. Postdatism is not a contraindication to TOL after Caesarean section (II-2B). 19. Every effort should be made to obtain the previous Caesarean section operative report to determine the type of uterine incision used. In situations where the scar is unknown, information concerning the circumstances of the delivery is helpful in determining the likelihood of a low transverse incision. If the likelihood of a low transverse incision is high, a TOL after Caesarean section can be offered (II-2B).

VALIDATION

These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.