Trial of labor versus elective cesarean delivery for patients with two prior cesarean sections: a systematic review and meta-analysis

Abstract

Objective

Cesarean section (CS) rates have been on the rise globally, leading to an increasing number of women facing the decision between a Trial of Labor after two Cesarean Sections (TOLAC-2) or opting for an Elective Repeat Cesarean Section (ERCS). This study evaluates and compares safety outcomes of TOLAC and ERCS in women with a history of two previous CS deliveries.

Methods

PubMed, MEDLINE, EMbase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for studies published until 30 June 2023. Eligible studies were included based on predetermined criteria, and a random-effects model was employed to pool data for maternal and neonatal outcomes.

Results

Thirteen studies with a combined sample size of 101,011 women who had two prior CS were included. TOLAC-2 was associated with significantly higher maternal mortality (odds ratio (OR)=1.50, 95% confidence interval (CI)= 1.25–1.81) and higher chance of uterine rupture (OR = 7.15, 95% CI = 3.44–14.87) compared to ERCS. However, no correlation was found for other maternal outcomes, including blood transfusion, hysterectomy, or post-partum hemorrhage. Furthermore, neonatal outcomes, such as Apgar scores, NICU admissions, and neonatal mortality, were comparable in the TOLAC-2 and ERCS groups.

Conclusion

Our findings suggest an increased risk of uterine rupture and maternal mortality with TOLAC-2, emphasizing the need for personalized risk assessment and shared decision-making by healthcare professionals. Additional studies are needed to refine our understanding of these outcomes in the context of TOLAC-2.

Keywords:

• Trial of labor
• elective cesarean delivery
• prior cesarean-sections
• systematic review
• meta-analysis
• maternal outcomes
• neonatal outcomes
• clinical decision-making

Introduction

The decision concerning the mode of delivery for women who had two prior cesarean sections (CS) has been a subject of ongoing debate and clinical inquiry [1,2]. Cesarean section rates have steadily risen worldwide, leading to a growing cohort of women facing the critical choice between attempting a Trial of Labor after Two Cesarean Sections (TOLAC-2) or opting for an Elective Repeat Cesarean Section (ERCS) [3,4]. This decision is complex, as it must balance the potential benefits of a successful vaginal birth against the risks associated with TOLAC-2, including uterine rupture and maternal morbidity [5].

Previous systematic reviews and meta-analyses [6,7] have explored outcomes related to Trial of Labor (TOL) as opposed to elective repeat cesarean delivery in women who had one previous CS. However, comprehensive evidence of such outcomes in women with two prior cesarean sections is still scarce. Given the unique obstetric challenges and potential risks associated with multiple prior CS, it is imperative to examine whether the outcomes observed in patients with a single prior CS can be extrapolated to those with a history of two previous CS.

This study aims to summarize current data and to compare maternal and neonatal outcomes in women with two prior cesarean sections, undergoing TOLAC-2 versus elective cesarean delivery.

Methods

Registration and search strategy

The Cochrane Handbook (version 5.1.0) [8], and the preferred reporting items for systematic reviews and meta-analyses (PRISMA) [9] were used for this systematic review. The review process was submitted to PROSPERO and assigned the registration number CRD42023445660.

Search strategy

Electronic searches were conducted in PubMed, EMbase, Google Scholar, and Cochrane Library databases for papers, published up to 30 June 2023. The search aimed to identify English-language studies in human subjects only that compared the maternal and neonatal outcomes associated with TOLAC and ERCS in women with a history of two previous CS deliveries. The search key terms were as follows: (“Trial of Labor after Two Cesarean Sections” OR “TOLAC-2” OR “Vaginal Birth after Two Cesarean Sections” OR “VBAC after Two C-sections” OR “Multiple C-sections and Labor”) AND (“Elective Repeat Cesarean Section” OR “ERCS” OR “Repeat C-section” OR “Planned C-section” OR “Elective Cesarean Birth” OR “Scheduled Cesarean Delivery”) AND (“Maternal Outcomes” OR “Maternal Health” OR “Maternal Morbidity” OR “Maternal Mortality” OR “Complications in Mothers” OR “Mother’s Health after Delivery”) AND (“Neonatal Outcomes” OR “New-born Health” OR “Neonatal Morbidity” OR “Neonatal Mortality” OR “Infant Outcomes” OR “Health of the Baby”). Additionally, the reference lists of the selected studies were hand-searched for additional relevant publications.

Study selection

Inclusion criteria

1. Study Types: randomized controlled trials (RCTs), cohort-, case-control, and observational studies available in peer-reviewed journals.

2. Participants: pregnant women with a documented history of two previous CS.

3. Interventions and Comparators: studies with a direct comparison of outcomes between TOLAC-2 and ERCS.

4. Outcomes: maternal (uterine rupture, blood transfusion, hysterectomy, post-partum hemorrhage, maternal mortality) and neonatal (Apgar scores, neonatal intensive care unit (NICU) admissions, and neonatal mortality) outcomes.

Exclusion criteria

1. Study Ty0pes: case reports, editorials, letters, conference abstracts, and review articles.

2. Participants: pregnant women with less than two prior Cesarean sections.

3. Outcomes: studies that did not report relevant maternal or neonatal outcomes.

Data extraction

Titles and abstracts of identified studies were assessed by the two reviewers separately for eligibility. Eligible studies were further evaluated for full-text review. A standardized data extraction form was used to collect study characteristics, such as authors, publication year, and study design, participant data, maternal and neonatal outcomes. Any differences were resolved by discussion.

Quality assessment

Two reviewers independently used the Newcastle– Ottawa scale (NOS) [10] to assesses quality of the studies based on selection, comparability, and exposure. Studies were scored from 0 to 8 (lowest and best quality, respectively).

Publication bias

Publication bias was assessed by funnel plot [11] and Egger’s regression test [12].

Statistical analysis

A fixed/random-effects model estimated the pooled odds ratio (OR) with 95% confidence interval (CI). Heterogeneity was assessed using restricted maximum-likelihood estimation and quantified using the I² statistics, with an I² value greater than 50% indicating significant heterogeneity [13]. Subgroup analyses were done to explore the connection between maternal (uterine rupture, blood transfusion, hysterectomy, post-partum hemorrhage, maternal mortality, and neonatal (Apgar scores, NICU admissions, and neonatal mortality) outcomes based on study design. Sensitivity analysis was done by sequentially excluding one study at a time from the pooled results. Statistical significance was defined as a p < 0.05. STATA, version 12.0 (Stata Statistical Software, Release 12; Stata Corp LP, College Station, TX) was used.

Results

Literature search

A comprehensive database search identified a total of 674 references. Of them, 592 were removed as duplicates. Additional 63 references were eliminated for not matching the inclusion criteria after reading the titles and abstracts, leaving 19 studies for the full-text examination. Finally, thirteen studies [14–26], involving 21,997 TOLAC-2 and 79,014 ERCS participants remained (Figure 1).

Figure 1. PRISMA 2020 Flow diagram for the selection of studies and specific reasons for exclusion from the present meta-analysis.

Characteristics of included studies

Of 13 included studies, one was cross-sectional, nine were retrospective and three were prospective cohort studies. These studies were conducted between 1989 and 2023. Geographically, seven studies were done in the US, and one each in Netherlands, France, Saudi Arabia, Poland, Israel and Italy. The number of patients varied significantly, ranging from 33 to 6035. The detailed baseline and clinical characteristics are shown in Table 1. The success rate of TOLAC-2 varied across the studies, ranging from 7.3% to 90%. Importantly, most studies were rated highly on the Newcastle-Ottawa Scale, indicating robust methodological quality (Table 2).

Table 1. Characteristics of included studies for TOLAC-2 vs. ERCS for patients with two prior cesarean-sections.

S. No	Author & Year	Country	Study design	Study duration	Settings	Inclusion criteria	TOLAC − 2 (n)	ERCS (n)	Mean Age_TOLAC-2	Mean Age_ERCS	Parity_TOLAC2	Parity_ERCS	Success rate of vaginal birth	Main outcome measured
1	Novas et al. 1989 [15]	USA	Retrospective Cohort	1986–1987	Personal computer-based perinatal data base system (BPM, Inc., Los Angeles, Calif.),	All patients with more than one previous cesarean section	36	33	NR	NR	NR	NR	29/36 (80%)	Uterine rupture, Hysterectomy, Perinatal death
2	Chattopadhyay et al. 1994 [14]	Saudi Arabia	Prospective Cohort	1986–1992	Maternity and Children’s Hospital, Riyadh, Saudi Arabia.	Women who had a history of two previous non-classical cesarean sections. Expressed a personal preference for vaginal delivery. Clinically assessed to have an adequate pelvis, further confirmed by an erect lateral X-ray pelvimetry indicating a true conjugate measurement greater than 10.5 cm. Ultrasound assessment indicated that the baby's size was less than 3.8 kg. Presented with a vertex fetal presentation at the onset of labor and were admitted before or early in labor with cervical dilatation less than 3 cm.	115	1006	NR	NR	Parity 2 = 23 Parity 3 = 40	NR	103/115 (90%)	Rates of vaginal delivery, scar dehiscence, uterine rupture and associated complications
3	Spaans et al. 2003 [16]	Netherlands	Retrospective Cohort	1988–1997	Amsterdam and Leiden University Medical Centre, Leiden	Retrospective analysis of medical records of women with a history of more than one previous caesarean section	59	187	NR	NR	NR	NR	49/59 (83%)	Uterine rupture, Blood transfusion, Hysterectomy, Maternal morbidity, Apgar score >7 at first minute, NICU admission
4	Macones et al. 2005 [17]	USA	Retrospective Cohort	1996–2000	Both tertiary care hospitals and community hospitals (with and without obstetrics/gynecology residency programs)	Secondary analysis of a retrospective cohort study, in which the medical records of more than 25,000 women with a prior cesarean delivery	1082	2888	30.9	32.1	NR	NR	VBAC-2 (74.6%) & VBAC-1 (75.5%)	Blood Transfusion, Uterine rupture, Fever, Birth weight
5	Landon et al. 2006 [18]	USA	Prospective Cohort	1999–2002	National Institute of Child Health and Human Development’s Maternal–Fetal Medicine Units Network	Women with prior cesarean delivery undergoing trial of labor and elective repeat operation	975	6035	30 (26–34)	30 (26–34)	NR	NR	648/975 (66%) in VBAC-2 & 12490/16915 (74%) in VBAC-1	Uterine rupture, Hysterectomy, Transfusion, Maternal morbidity, Term NICU admission, Term intrapartum stillbirth
6	Miller et al. 2015 [19]	USA	Prospective Cohort	1999–2002	19 academic medical centers	Women were included in the present analysis if they had 1 or 2 prior CD, a singleton gestation, and no contraindication to a vaginal delivery (e.g., placenta previa, breech presentation).	152	6010	30.8 ± 5.4	29.9 ± 5.5	NR	NR	75% success in VBAC-2 & 83% in VBAC-1	Maternal and perinatal outcomes including the frequency of VBAC and maternal complications were compared
7	Modzelewski et al. 2019 [20]	Poland	Retrospective Cohort	2010–2017	Anonymous electronic records of all singleton deliveries	Women with previous two cesarean deliveries were identified, and individual. paper records were analyzed to extract data unavailable in electronic records.	35	377	32.4 ± 4.27	35.3 ± 3.83	3.38 ± 0.89	3.07 ± 0.41	22/35 (62.85%)	Uterine rupture, Haemorrhage, Surgical complications, Need of additional haemostatic procedures, Need of transfusion,
8	De Leo et al. 2020 [21]	Italy	Retrospective Cohort	Jan 2011–Dec 2019	San Giacomo Hospital, Castelfranco, Veneto (Italy).	Singleton pregnancies, absence of morphological abnormalities at ultrasonographic screening of the second trimester (or at any other stage of pregnancy), and two previous cesarean sections	46	68	34.6 ± 5.2	34.7 ± 4.5	NR	NR	35/46 (76.1%)	Hospital stay, Apgar scores at 5minutes <7, non-reassuring fetal heart rate, onset of spontaneous labor after premature rupture of membranes
9	Dombrowski et al. 2020 [22]	USA	Retrospective Cohort	2010–2012	comprehensive data set obtained from the California Office of Statewide Health Planning and Development, which consisted of linked information from hospital discharge records (mother and neonate) and birth certificates for births in California	Women with two prior cesarean deliveries were included in the study if they met the following criteria: they had live singleton births at 37–42 weeks of gestation, no congenital anomalies or clear contraindications to trial of labor (such as malpresentation, genital herpes, placenta previa, or vasa previa), no missing or erroneous information on parity (e.g. a parity of less than 2 that contradicts two prior cesarean deliveries), and successful linkage across maternal hospital discharge records, newborn hospital discharge records, and birth certificates.	1228	41543	31.3 ± 5.4	31.1 ± 5.3	Parity 2 = 831 Parity 3 = 230 Parity 4 = 167	Parity 2 = 3943 Parity 3 = 5046 Parity 4 = 2554	484/1228 (39.4%)	Severe maternal morbidity, Length of stay, NICU admission
10	Wagner et al. 2021 [23]	USA	Cross Sectional	2014–2018	U.S. National Vital Statistics linked birth and infant death data.	Term, cephalic, singleton pregnancies with two prior cesarean births.	17,607	17607	30.1 ± 0.5	30 ± 0.5	NR	NR	1285/17607 (7.3%)	Adverse neonatal outcomes (Apgar score <5 at 5 min, assisted ventilation >6 h, neonatal seizures, or neonatal death within 27 days). maternal composite and the cesarean birth rate.
11	Rotem et al. 2021 [24 ]	Israel	Retrospective Cohort	2005–2009	Shaare Zedek Medical Center (SZMC)	Parturients between 24 and 42 weeks of gestations who had two prior CDs and subsequently had vaginal vertex births and parturients who chose to have a repeat elective CD.	485	2234	34.4 ± 4.3	33.49 ± 5.1	5 (4–7)	3 (3–5)	417/485 (86%)	Uterine rupture, rates of hysterectomy, re-laparotomy, blood product infusion, and ICU admission
12	Horgan et al. 2022 [25]	USA	Retrospective Cohort	Jan 2008–Dec 2018	Monmouth Medical Center in New Jersey	Women with a vertex singleton gestation at term and a history of two prior cesarean sections.	82	711	33.1 ± 4.7	33 ± 4.8	4.1 (2.8)	2.1 (0.6)	57/82 (69.5%)	NICU admissions, 5-min APGAR scores <7, uterine rupture rate, maternal morbidity, maternal and neonatal mortalities
13	Roux et al. 2023 [26]	France	Retrospective Cohort	Jan 2013–Dec 2020	Rennes University Hospital	All patients who delivered at a term ≥ 37 SA of a singleton fetus in cephalic presentation and who had previously delivered twice by cesarean section	95	315	NR	NR	2.8 ± 1.3	2.8 ± 1.3	64/95 (67.3%)	Cord pH, cord lactates, Apgar scores, transfer to neonatal unit and deaths, uterine rupture, PPH, deaths.

Abbreviations: PC, Prospective Cohort; RC, Retrospective Cohort; NR, not reported; VBAC, vaginal birth after caesarean; RCS, repeat (third) caesarean section; TOLAC, trial of labor after cesarean section; NICU, Neonatal intensive care unit; PPM, post-partum hemorrhage; Apgar, Appearance, Pulse, Grimace, Activity, and Respiration; CS, cesarean section.

Table 2. Quality assessment of included studies based on Newcastle-Ottawa Scale (NOS).

	Selection					Comparability	Outcome			Result
S. No	First author, publication year	Representative-ness of the exposed cohort	Selection of the non-exposed cohort	Ascertainment of exposure	Demonstration that outcome of interest was not present at start of study	Comparability of cohorts on the basis of the design or analysis	Assessment of outcome	Was follow-up long enough for outcomes to occur	Adequacy of follow up of cohorts	Total score
1	Novas et al. 1989 [15]	1	1	1	1	0	1	0	1	6
2	Chattopadhyay et al. 1994 [14]	1	1	1	1	0	1	1	1	7
3	Spaans et al. 2003 [16]	1	1	1	1	0	1	0	1	6
4	Macones et al. 2005 [17]	1	1	1	1	1	0	1	1
5	Landon et al. 2006 [18]	1	1	1	1	0	1	1	1	7
6	Miller et al. 2015 [19]	1	1	1	1	1	1	0	1	7
7	Modzelewski et al. 2019 [20]	1	1	1	1	1	1	1	1	8
8	De Leo et al. 2020 [21]	1	1	1	1	0	1	1	1	7
9	Dombrowski et al. 2020 [22]	1	1	1	1	1	1	0	1	7
10	Wagner et al. 2021 [23]	1	1	1	1	1	1	0	1	7
11	Rotem et al. 2021 [24]	1	1	1	1	1	1	1	1	8
12	Horgan et al. 2022 [25]	1	1	1	1	1	1	0	1	7
13	Roux et al. 2023 [26]	1	1	1	1	1	1	1	1	8

Maternal outcome

Uterine rupture

TOLAC-2 correlated with statistically significantly increased incidence of uterine rupture as compared to ERCS (OR = 7.15; 95% CI: 3.44–14.87). Subgroup analysis based on study design indicated a significant 7.44-fold rise in the rates of uterine rupture (95% CI: 2.68–20.62) in retrospective cohort studies. Prospective cohort studies showed a similar 8.08-fold increase (95% CI: 0.65–100.37), but with greater uncertainty due to a smaller sample size (Supplementary Figure 1).

Hysterectomy

The analysis of eight studies found no correlation between TOLAC-2 and a higher risk of hysterectomy (OR 1.28, 95% CI 0.77–2.14) (Supplementary Figure 2). While retrospective (OR 1.82, 95% CI 0.39–8.64) and prospective cohort studies (OR 1.27, 95% CI 0.58–2.78) both also showed a trend toward increased risk of hysterectomy with TOLAC-2, the results were not statistically significant.

Blood transfusion

Overall, there was no association between TOLAC-2 and an increased risk of blood transfusion (OR 1.07, 95% CI 0.72–1.59). However, in prospective cohort studies, there was a significant link between TOLAC-2 and higher risk of blood transfusion (OR 1.93, 95% CI 1.31–2.84) (Supplementary Figure 3).

Post-partum hemorrhage

No data was available for prospective cohort or cross-sectional studies for post-partum hemorrhage. However, the analysis of included retrospective cohort studies showed no significant association between TOLAC-2 and postpartum hemorrhage (OR 0.90, 95% CI 0.56–1.46) (Supplementary Figure 4).

Maternal mortality

Meta-analysis of eight studies showed that TOLAC-2 was linked to statistically significant increase in the incidence of maternal mortality compared to ERCS (OR = 1.50; 95% CI: 1.25–1.81) (Supplementary Figure 5). In retrospective cohort studies (three studies), the OR for maternal mortality was 1.36 (95% CI: 1.03–1.81), indicating a significant association with TOLAC-2. Among prospective cohort studies (two studies), the OR was 1.54 (95% CI: 1.04–2.27), also suggesting a significant link with TOLAC-2.

Neonatal outcome

Apgar score less than 7 after 5 min

The overall analysis of all included studies showed the OR of 1.29 (95% CI: 0.95 to 1.73), indicating a trend toward Apgar score less than 7 after 5 min in the TOLAC-2 as compared to ERCS group, but no statistical significance (Supplementary Figure 6). A similar line of evidence was also noted for retrospective cohort studies (OR 1.61, 95% CI 0.53–4.86).

Neonatal intensive care unit (NICU) admission

Overall, the analysis of all available studies showed somewhat increased but not significant risk of NICU admission in the TOLAC-2 group (OR 1.23, 95% CI 0.84–1.79). Retrospective cohort studies showed a significant correlation between TOLAC-2 and a higher likelihood of NICU admission (OR 1.61, 95% CI 1.20–2.17). Prospective cohort studies showed an increased but not significant risk (OR 1.53, 95% CI 0.40–5.92) (Supplementary Figure 7]).

Neonatal mortality

Overall, there was no association of TOLAC-2 and neonatal mortality (OR 2.47, 95% CI 0.70–8.76) (Supplementary Figure 8). The somewhat increased risk of neonatal mortality in TOLAC-2 group that was observed in retrospective and prospective cohort studies, was not significant (OR 3.65, 95% CI 0.95–14.08; OR 6.19, 95% CI 0.39–99.04, respectively).

Publication bias and Sensitivity analysis

As shown in Figure 2(a–e) for maternal outcomes and Figure 3(a–c) for neonatal outcomes, funnel plot did not detect any apparent signs of asymmetry. The distribution of studies around the estimated effect appeared to be even, suggesting the absence of significant publication bias that could impact the results. Sensitivity analysis demonstrated that the pooled estimates for maternal and neonatal outcomes did not exhibit significant variations, indicating the stability of the results (Supplementary Figures 9 and 10).

Figure 2. Funnel plot for maternal outcomes in TOALC-2 versus ERCS groups (a) uterine rupture, (b) hysterectomy, (c) blood Transfusion, (d) post-partum Hemorrhage, and (e) Maternal mortality.

Figure 3. Funnel plot for neonatal outcomes in TOALC-2 versus ERCS groups (a) APGAR score < 7 after 5 min, (b) NICU admission, (c) and Neonatal mortality.

Discussion

Our findings show that TOLAC-2 is associated with worse maternal outcomes, such as an increased risk of uterine rupture and maternal mortality. However, no significant association was found in terms of the need for blood transfusion, hysterectomy, or post-partum hemorrhage, as well as for neonatal outcomes, including Apgar scores, NICU admissions, and neonatal mortality. Our results further confirm that the decision to pursue TOLAC-2 requires a careful assessment of patient-specific factors. Criteria typically include a thorough evaluation of the woman’s obstetric history, uterine scar integrity, the reason for previous CS, and the presence of any contraindications such as placenta previa. Additionally, maternal preferences and informed consent play pivotal roles in the decision-making process.

One of the key observations of our study relates to maternal outcomes, particularly the incidence of uterine rupture. In our analysis, the TOLAC-2 group had an increased risk of this specific outcome compared to the ERCS group. This finding aligns with existing literature that has emphasized the importance of assessing the risk of uterine rupture when considering TOLAC-2 [27]. In the context of shared decision-making, both clinicians and patients play active roles in selecting the optimal treatment approach. This collaborative process facilitates well-informed decisions that consider the patient’s preferences, values, and goals, alongside the expertise and knowledge of the healthcare provider. Such an approach underscores the importance of meticulous patient selection and ongoing monitoring to mitigate potential risks effectively.

However, it’s worth noting that the risk of uterine rupture can vary significantly depending on various factors, such as a woman’s previous uterine scar, the number of previous Cesarean sections, and other clinical variables. Therefore, individualized risk assessment is essential when considering TOLAC-2 [28]. No statistically significant association was found between TOLAC-2 and an increased risk of hysterectomy. However, the wide confidence interval indicates some uncertainty in the estimate. It is important to consider that hysterectomy is a serious maternal morbidity, and additional studies would need to address the nuances of this outcome in the context of TOLAC-2. While we observed a potential elevated risk of neonatal admission to the NICU in the TOLAC-2 group in retrospective cohort studies, this association was not significant. Similarly, no correlation was found between TOLAC-2 and neonatal mortality or low Apgar scores.

Previous meta-analysis by Tahseen et al. [6] reported on the outcomes of VBAC-2, shedding light on the challenges and risks associated with multiple prior cesarean sections. While their study primarily compared VBAC-2 to VBAC-1 and third CS, and our study specifically investigated TOLAC-2 versus ERCS, there are valuable insights to be gained from Tahseen et al. [6] work. Our study indicates similar trends in uterine rupture or maternal outcomes between TOLAC-2 and ERCS. Therefore, it is plausible that the number of prior cesarean sections may not be the sole determinant of outcomes. Other factors, such as individual patient characteristics and clinical management, may also play significant roles.

Recent meta-analysis by Qiu et al. [7] focused on the safety of TOLAC versus ERCS. While our study shares the primary comparison of TOLAC versus ERCS, there are differences in scope and inclusion criteria. Our study specifically focuses on TOLAC-2, which involves women with two prior CS. Comparisons with these studies may reveal common trends or detect points of interest for further research.

TOLAC-2 carries a significantly higher risk of uterine rupture compared to ERCS. This may lead to serious maternal and fetal complications, necessitating a careful risk-benefit assessment. ERCS correlates with a lower risk of uterine rupture, making it a safer option for some women. ERCS also allows for planned and controlled delivery, reducing the uncertainty associated with labor. Nevertheless, the field of obstetrics and gynecology has consistently grappled with unique ethical dilemmas surrounding the application of informed consent on a global scale. Further research is essential to generalize the suggested criteria. A significant proportion of women lack awareness regarding the overall success rates (60–80%) and the low risk of uterine rupture (<1%) associated with TOLAC [29]. In general, there is a lack of consensus regarding the ideal timing for engaging in shared decision-making for TOLAC. Some argue that discussions should occur early, possibly in the immediate postnatal period following the primary cesarean delivery, allowing ample time for reflection and consideration [30]. Conversely, others suggest that the decision should be postponed to later stages in the pregnancy, presumably when the progression of the pregnancy is evident, and the absence of additional risk factors is known. Additionally, the timing of decision-making may be influenced by organizational, logistical, or cultural factors, necessitating further investigation. Previous meta-analysis [7] comparing TOLAC-and ERCS suggests that TOLAC-1 is generally linked to lower risks of uterine rupture compared to TOLAC-2. This distinction underscores the importance of distinguishing between these two scenarios when considering the potential for vaginal birth after the cesarean section. The utilization of prostaglandins for labor induction in women undergoing TOLAC amplifies the risk of uterine rupture [31]. One plausible explanation for the heightened risk associated with prostaglandin use is its potential to induce ultrastructural changes that weaken the scar [32]. A meta-analysis investigating the use of oxytocin for labor induction or augmentation revealed a pooled uterine rupture rate of 1.4% in women using oxytocin, as opposed to 0.5% in those not using oxytocin [33].

TOLAC-2 differs from TOLAC-1 in that it involves a more complex clinical scenario. An additional previous surgery can increase the risk of uterine scar weaknesses and complications during labor, making TOLAC-2 inherently riskier [5,34]. Thus, TOLAC-2 necessitates even more stringent to select patients and careful monitoring. The failure of TOLAC-2, leading to an unplanned cesarean section, can result in poorer maternal and neonatal outcomes compared to planned ERCS. Women choosing TOLAC may experience a prolonged gestation, offering potential benefits for neonates in terms of reduced short- and long-term complications, including lower mortality and morbidity rates, fewer respiratory issues, and improved neurological, respiratory, and cardiovascular outcomes [35–37]. It is advisable that mothers consider scheduling cesarean delivery after 39 weeks of gestation, and if spontaneous labor arises before the planned date, they may opt for TOLAC rather than resorting to emergency cesarean delivery. Emergency cesarean sections can be associated with increased stress and complications for both the mother and the infant. Therefore, the potential for TOLAC-2 failure must be factored into the decision-making process when considering this approach.

Our study has some limitations that have substantial implications for the reliability and applicability of our findings. These include patient-specific factors, influencing individualized decisions, variability in data due to differences in sample size, study design and demographics, complex ethical considerations affecting choices, to recall bias and confounding variables, limited long-term follow-up data, evolving clinical practices not always reflected in studies, heterogeneity in outcome definitions, small sample sizes affecting statistical power, and the presence of unmeasured or unaccounted-for confounding variables that can impact results. These limitations underline the importance of considering individual patient circumstances and preferences when making obstetric decisions.

However, our findings hold important clinical implications. When considering TOLAC-2, clinicians should carefully assess the individual risk factors and preferences of the patient. Our results suggest that uterine rupture remains a significant concern, and clinicians should engage in shared decision-making with patients, providing clear information about the potential risks and benefits of TOLAC-2 [38–40]. Future research should aim to gather more robust evidence on the safety and efficacy of TOLAC-2, ideally through well-designed prospective studies or large-scale multi-centre trials.

Conclusions

Our findings suggest an increased risk of uterine rupture and maternal mortality with TOLAC-2, highlighting the need for personalized risk assessment and shared decision-making in clinical practice. Moreover, the uncertainty in some of our estimates underscores the need for further research to refine our understanding of these outcomes in the context of TOLAC-2.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.

Additional information

Funding

This study is funded by Huzhou Science and Technology Bureau [2022GY41].