The management of labor in women with more than one uterine scar: is a repeat cesarean section really the only "safe" option?

Trial of labor after 2 previous cesareans: a multicenter study

BACKGROUND

Trial of labor after cesarean after 2 cesarean deliveries is linked to a lower success rate of vaginal delivery and higher rates of adverse obstetrical outcomes than trial of labor after cesarean after 1 previous cesarean delivery.

OBJECTIVE

This study aimed to investigate the factors associated with failed trial of labor after cesarean among women with 2 previous cesarean deliveries.

STUDY DESIGN

This was a multicenter retrospective cohort study, which included all women with singleton pregnancies attempting trial of labor after cesarean after 2 previous cesarean deliveries between 2003 and 2021. This study compared labor, maternal, and neonatal characteristics between women with failed trial of labor after cesarean and those with successful trial of labor after cesarean. Univariate analysis was initially performed, followed by multivariable analysis (adjusted odds ratios with 95% confidence intervals).

RESULTS

The study included a total of 1181 women attempting trial of labor after cesarean after 2 previous cesarean deliveries. Among these cases, vaginal birth after cesarean was achieved in 973 women (82.4%). Women with failed trial of labor after cesarean had higher rates of maternal and neonatal morbidities. Several factors were found to be associated with failed trial of labor after cesarean, including longer interpregnancy and interdelivery intervals, lower gravidity and parity, lower rates of previous successful vaginal delivery, smoking, earlier gestational age at delivery (38.3±2.1 vs 39.5±1.3 weeks), late preterm delivery (34-37 weeks of gestation), lower cervical dilation on admission, no use of epidural, and smaller neonatal birthweight. Our multivariable model revealed that late preterm delivery (adjusted odds ratio, 3.79; 95% confidence interval, 1.37-10.47) and cervical dilation on admission for labor <3 cm (adjusted odds ratio, 2.58; 95% confidence interval, 1.47-4.54) were associated with higher odds of failed trial of labor after cesarean.

CONCLUSION

In the investigated population of women with 2 previous cesarean deliveries undergoing trial of labor after cesarean, admission at the late preterm period with a cervical dilation of <3 cm, which reflects the latent phase, may elevate the risk of failed trial of labor after cesarean and a repeated intrapartum cesarean delivery.

Trial of Labor after Three or More Previous Cesarean Sections: Systematic Review and Meta-Analysis of Observational Studies

Aims To assess the success rate and prevalence of maternal or neonatal complications in women undergoing a trial of labor after three or more (≥3) previous cesarean sections (CSs).

Methods A systematic literature review and meta-analysis was conducted from inception to May 2022 in Medline, Scopus, ENBASE, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials and Reviews. Items detailing success rate and complications in women with a history of≥3 previous CSs were considered. Selected articles were evaluated for quality, heterogeneity, and publication bias. A pooled prevalence or odds ratio was calculated.

Findings Twelve articles were included for a total of 540 women with a history of≥3 CSs, accounting for the 2% (CI 95% 1–4%) of the whole cohort of trial of labor. Our findings show a 0.67 (CI 95% 0.53–0.78) rate of successful vaginal delivery. A higher success rate was observed in women having a history of a prior vaginal delivery (0.90, CI 95% 0.77–0.96) and when prostaglandins, peridural anesthesia or oxytocin were allowed (respectively 0.73, CI 95% 0.62–0.83, 0,73, CI 95% 0.57–0.85 and 0.73, CI 95% 0.64–0.81). Uterine rupture rate was 0.01 (CI 95% 0.00–0.01). No cases of fetal asphyxia or maternal or neonatal death were registered.

Conclusions The success rate and low frequency of severe complications observed seem to support a trial of labor in selected patients desiring a natural birth. However, a potential underestimation of serious maternal and neonatal complications should be considered in the decision-making process.

Maternal and Neonatal Outcomes Following Trial of Labor After Two Previous Cesareans: a Retrospective Cohort Study

The objective of this study is to evaluate the maternal and neonatal outcomes of parturients attempting trial of labor (TOL) after two previous CD versus those who had an elective third repeat CD. A retrospective computerized database cohort study was conducted at a single tertiary center between 2005 and 2019. Various maternal and neonatal outcomes were compared between parturients attempting TOL after two CD versus parturients opting for elective third repeat CD. TOL after two CD was allowed only for those who met all the criteria of our departments' protocol. Parturients with identified contraindication to vaginal delivery were excluded from the analysis. A univariate analysis was conducted and was followed by a multivariate analysis. A total of 2719 eligible births following two CD were identified, of which 485 (17.8%) had attempted TOL. Successful vaginal delivery rate following two CDs was 86.2%. Uterine rupture rates were higher among those attempting TOL (0.6% vs 0.1% p = 0.04). However, rates of hysterectomy, re-laparotomy, blood product infusion, and intensive care unit admission did not differ significantly between the groups. Neonatal outcomes following elective repeat CD were less favorable (specifically, neonatal intensive care unit admission and composite adverse neonatal outcome). Nonetheless, when controlling for potential confounders, an independent association between composite adverse neonatal outcome and an elective repeat CD was not demonstrated. In a subgroup analysis, diabetes mellitus and hypertensive disorders of pregnancy were found independently associated with failed TOLAC. When following a strict protocol, TOL after two CD is a reasonable alternative and associated with favorable outcomes.

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

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

OBJECTIVE

This study was undertaken to compare clinical outcomes in women with 1 versus 2 prior cesarean deliveries who attempt vaginal birth after cesarean delivery (VBAC) and also to compare clinical outcomes of women with 2 prior cesarean deliveries who attempt VBAC or opt for a repeat cesarean delivery.

STUDY DESIGN

We performed a secondary analysis of a retrospective cohort study, in which the medical records of more than 25,000 women with a prior cesarean delivery from 16 community and tertiary care hospitals were reviewed by trained nurse abstractors. Information on demographics, obstetric history, medical and social history, and the outcomes of the index pregnancy was obtained. Comparisons of obstetric outcomes were made between women with 1 versus 2 prior cesarean deliveries, and also between women with 2 prior cesarean deliveries who opt for VBAC attempt versus elective repeat cesarean delivery. Both bivariate and multivariate techniques were used for these comparisons.

RESULTS

The records of 20,175 women with one previous cesarean section and 3,970 with 2 prior cesarean sections were reviewed. The rate of VBAC success was similar in women with a single prior cesarean delivery (75.5%) compared with those with 2 prior cesarean deliveries (74.6%), though the odds of major morbidity were higher in those with 2 prior cesarean deliveries (adjusted odd ratio[OR] = 1.61 95% CI 1.11-2.33). Among women with 2 prior cesarean deliveries, those who opt for a VBAC attempt had higher odds of major complications compared with those who opt for elective repeat cesarean delivery (adjusted OR = 2.26, 95% CI 1.17-4.37).

CONCLUSION

The likelihood of major complications is higher with a VBAC attempt in women with 2 prior cesarean deliveries compared with those with a single prior cesarean delivery. In women with 2 prior cesarean deliveries, while major complications are increased in those who attempt VBAC relative to elective repeat cesarean delivery, the absolute risk of major complications remains low.

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.

Planned elective repeat caesarean section versus planned vaginal birth for women with a previous caesarean birth

BACKGROUND

When a woman has had a previous caesarean birth, there are two options for her care in a subsequent pregnancy: planned elective repeat caesarean or planned vaginal birth. While there are risks and benefits for both planned elective repeat caesarean birth and planned vaginal birth after caesarean, current sources of information are limited to non-randomised cohort studies. Studies designed in this way have significant potential for bias and consequently conclusions based on these results are limited in their reliability and should be interpreted with caution.

OBJECTIVES

To assess, using the best available evidence, the benefits and harms of a policy of planned elective repeat caesarean section with a policy of planned vaginal birth after caesarean section for women with a previous caesarean birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (24 June 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2004), and PubMed (1966 to 24 June 2004).

SELECTION CRITERIA

Randomised controlled trials with reported data that compared outcomes in mothers and babies who planned a repeat elective caesarean section with outcomes in women who planned a vaginal birth, where a previous birth had been by caesarean.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

There were no randomised controlled trials identified.

REVIEWERS' CONCLUSIONS

Planned elective repeat caesarean section and planned vaginal birth after caesarean section for women with a prior caesarean birth are both associated with benefits and harms. Evidence for these care practices is drawn from non-randomised studies, associated with potential bias. Any results and conclusions must therefore be interpreted with caution. Randomised controlled trials are required to provide the most reliable evidence regarding the benefits and harms of both planned elective repeat caesarean section and planned vaginal birth for women with a previous caesarean birth.

Primary nonmedically indicated cesarean section ("section on request"): evidence based or modern vogue?

Cesarean section, initially described as an emergency operative procedure for delivering moribund parturients, is now advocated by many as a routine technique with major advantages over vagi-nal delivery. In fact, it has been suggested that labor and vaginal delivery are no longer the desired consequence of pregnancy, a conclusion that reflects perceived medical advantages and patient and physician convenience. This article systematically reviews the various medical implications to the mother and infant of this procedure in the hope of facilitating a more rational approach to this spreading and controversial phenomenon.

Higher order multiple repeat cesarean sections: maternal and fetal outcome

BACKGROUND

Multiple repeat cesarean delivery is common in many parts of Saudi Arabia. We conducted a retrospective analysis of patient records to determine the major and minor complications as well as the neonatal outcome associated with multiple repeat cesarean sections.

METHODS

We analyzed relationships between the number of cesarean sections and various demographic and clinical variables in 150 patients undergoing 4 to 8 cesarean sections (mean 6.0) compared with a control group of 140 patients undergoing 2 to 3 cesarean sections (mean 2.5) during the period from 1996 to 2000 at the Security Forces Hospital, Riyadh, Kingdom of Saudi Arabia.

RESULTS

Both the gestation age of the mother and birth weight of the baby were lower in the study group compared with the control group (mean gestation age 36 weeks in the study group compared with 37 weeks in the control group (P=0.001), and mean birth weight 2.9 kg for infants in the study group compared with 3.1 kg in the control group (P=0.01). The total duration of the operation was longer in the study group (63 minutes on average) compared with the control (45 minutes on average) (P=0.001). There were 80 cases of severe adhesion encountered during surgery in the study group compared with 40 cases in the control group (P=0.001). There was no difference in the Apgar score of the baby and the neonatal admission rate in the two groups. The incidence of cesarean hysterectomy, uterine scar dehiscence, placenta placenta previa, placenta accreta and bladder injury was similar in two groups. The incidence of post partum pyrexia, wound infection, urinary tract infection, and blood transfusion was also comparable in the two groups.

CONCLUSION

No specific additional risk is associated with higher order (four to eight) repeat cesarean sections that is not normally encountered with lower order (two to three) repeat cesarean sections.

Risk factors for uterine rupture during a trial of labor after cesarean

The rate of vaginal birth among women with a previous cesarean increased from 18.9% in 1989 to 28.3% in 1996. By 1998, the rate had decreased to 26.3% and preliminary data from 1999 suggest that the rate for that year would be even lower (23.4%). It is not known whether that decrease represents a trend related to increasing concern by providers and women about the risk of uterine rupture. Whereas the overall risk of rupture is 1%, our review demonstrates that there is considerable variation of that risk. More than one previous scar, induction of labor, a short interdelivery interval, or a history of postpartum fever during a previous cesarean may increase the risk of a uterine rupture during a trial of labor. However, there does not appear to be an increase in risk associated with low-vertical scars, and a previous vaginal delivery may be somewhat protective. Further delineation of the factors that increase the risk of uterine rupture will permit better prediction of individualized risk and identification of women for whom attempting a vaginal delivery after cesarean represents a safe option.

Vaginal birth following two previous cesarean sections

OBJECTIVE

To evaluate the management of vaginal delivery among women with two previous cesarean sections. The maternal and fetal morbidities of this attitude were studied.

SETTING

University hospital.

DESIGN

Retrospective study made over 6 years, from January 1st 1990 to December 31st 1995.

PATIENTS

Among 180 patients with two uterine scars, 96 patients with cephalic presentation and normal pelvic dimensions were allowed trial of labor.

RESULTS

The rate of vaginal birth following trial of labor was 65.6%. Three patients had an uterine scar dehiscence; among them, one hysterectomy was performed for haemorrhage with uterine atony. Neonatal issue was always favorable. Twenty-two newborns had superior birthweights compared to those born from the preceding cesarean section.

CONCLUSION

Trial of labor following two previous cesarean sections is acceptable in the majority of cases. It leads to a high vaginal delivery rate and low maternal and fetal morbidity.

Elective repeat cesarean delivery versus trial of labor: a meta-analysis of the literature from 1989 to 1999

OBJECTIVE

The aim of this study was to compare a trial of labor with elective repeat cesarean delivery among women with previous cesarean delivery.

STUDY DESIGN

We searched MEDLINE and EMBASE databases from 1989 through 1999 with the following terms: vaginal birth after cesarean delivery, trial of labor, trial of scar, and uterine rupture. We included all controlled trials from developed countries in which the control group had been eligible for a trial of labor. Outcomes of interest were uterine rupture, hysterectomy, maternal febrile morbidity, maternal mortality, 5-minute Apgar score <7, and fetal or neonatal mortality. We computed pooled odds ratios for each outcome.

RESULTS

The search strategy identified 52 controlled studies, 37 of which were excluded because many of the control subjects were not eligible for a trial of labor. Fifteen studies with a total of 47,682 women were included. Uterine rupture occurred more frequently among women undergoing a trial of labor than among those undergoing elective repeat cesarean delivery (odds ratio, 2.10; 95% confidence interval, 1.45-3.05). There was no difference in maternal mortality risk between the 2 groups (odds ratio, 1.52; 95% confidence interval, 0.36-6.38). Fetal or neonatal death (odds ratio, 1.71; 95% confidence interval, 1.28-2.28) and 5-minute Apgar scores <7 (odds ratio, 2.24; 95% confidence interval, 1.29-3.88) were more frequent in the trial of labor group than in the control group. Mothers undergoing a trial of labor were less likely to have febrile morbidity (odds ratio, 0.70; 95% confidence interval, 0.64-0.77) or to require transfusion (odds ratio, 0.57; 95% confidence interval, 0.42-0.76) or hysterectomy (odds ratio, 0.39; 95% confidence interval, 0.27-0.57).

CONCLUSION

A trial of labor may result in small increases in the uterine rupture rate and in fetal and neonatal mortality rates with respect to elective repeat cesarean delivery. Maternal morbidity, including febrile morbidity, and the need for transfusion or hysterectomy may be reduced with a trial of labor.

Vaginal birth after cesarean

Vaginal birth or trial of labor after previous cesarean delivery represents one of the most significant changes in obstetric practice. There are numerous reasons that influence the decision to proceed with either a trial of labor after previous cesarean delivery or elective repeat cesarean delivery. For the majority of women with a previous cesarean delivery, a trial of labor should be encouraged. There are few absolute contraindications. Women with a previous classical uterine incision should not undergo a trial of labor and should be delivered once fetal lung maturity is documented. An attempted trial of labor should not be discouraged in women with a previous low vertical uterine incision, although the patient should be counseled that the evidence as to the risks and benefits of a trial of labor is limited. In those situations where the previous uterine incision is unknown, but suggestive of a classical uterine incision, an argument can be made for elective repeat cesarean delivery once fetal lung maturity is documented. When the history of a uterine incision is unknown and unlikely to be classical, a trial of labor can be attempted after counseling. Close intrapartum management is warranted in this situation. The optimal management of labor in women with a previous low transverse uterine incision who desire a trial of labor with a breech presentation, multiple gestation, orin whom induction of labor is necessary is uncertain; the evidence as to the risks and benefits of a trial of labor is limited and obstetric management should be individualized after counseling. Uterine rupture represents the most catastrophic complication of a trial of labor after previous cesarean delivery. In women suspected of having a uterine scar injury, prompt intervention is necessary to minimize both maternal and neonatal complications. Women who are not successful with a trial of labor require repeat cesarean delivery and appear to be at greatest risk for maternal complications. Identifying those women most likely to be successful with an attempted trial of labor after previous cesarean while also incurring the least maternal and perinatal morbidity and mortality would be ideal. At present, however, there is no sufficiently predictive method to identify those women most likely to benefit from an elective repeat cesarean delivery. The management of labor in women with a previous uterine scar is not low risk. As the number of women who attempt vaginal birth after previous cesarean delivery increases, we should focus on trying to develop reliable methods of identifying women who should and should not undertake a trial of labor after cesarean delivery.