Predicting successful vaginal birth after Cesarean section using a model based on Cesarean scar features examined by transvaginal sonography

Evaluation of Association Between Adenomyosis and Cesarean Scar Defect

PURPOSE

This study aims to investigate and compare quantitative factors of the cesarean scar defect (CSD) in symptomatic patients with and without uterine adenomyosis.

METHOD

This study was conducted as a case-control study. Patients who met the inclusion criteria were divided into two groups: with adenomyosis (case) and without adenomyosis (control). The demographic data, medical history, and sonohysterography findings were extracted from the patient's documents and archived images.

RESULT

During 2 years, 310 symptomatic women with a history of previous cesarean section underwent sonohysterography. Among them, 204 patients met the inclusion criteria. The most common chief complaints were post-menstrual bleeding (34.3%) and prolonged bleeding (27%). Cesarean scar depth and width significantly differed between these two groups, and patients with underlying adenomyosis had significantly larger defects (P-value of .009 and .005, respectively). Mean RMT/AMT ratio was 31.83% in the case group and 42.88% in the control group. In our study, RMT/AMT ratios were significantly lower in the case group (P-value of .001). In addition, we performed analysis on a subgroup of patients with one prior cesarean section. Similar results were achieved with a lower RMT/AMT ratio in case group (mean of 31.20% in case group and 46.47% in control group; P-value of .000).

CONCLUSION

Our study showed a strong association between the presence of adenomyosis and larger clinically more significant CSDs. To establish a causative relationship, we suggest a prospective cohort study to follow up the patients and compare the evolution of CSD in patients with and without adenomyosis.

Prediction of vaginal birth after cesarean in China

OBJECTIVE

This study aimed to develop and validate a prediction model of vaginal birth after cesarean delivery (VBAC) in China.

METHODS

A nomogram for effective prediction of VBAC of singleton, cephalic and one previous low-transverse cesarean section deliveries was created by comparing the combinations of ultrasonographic and non-ultrasonographic factors from five hospitals between 2018 and 2019.

RESULTS

A total of 1066 women were included. Of the women who underwent trial of labor after cesarean (TOLAC), 854 (80.1%) had a VBAC. Ultrasound factors included reached a higher area under the curve (AUC) combined with non-ultrasonographic factors. Of the three ultrasonographic factors analyzed, the best predictive factor for successful TOLAC was fetal abdominal circumference. A nomogram was generated with eight validated factors, including maternal age, gestational week, height, previous vaginal delivery, Bishop score, dilatation of the cervix at the time of admission, body mass index at delivery, and fetal abdominal circumference by ultrasound. The trained and validated AUC were 0.719 (95% confident interval 0.674-0.764) and 0.774 (95% confident interval 0.712-0.837), respectively.

CONCLUSION

Our VBAC nomogram based on obstetric factors and fetal abdominal circumference obtained by ultrasound could be used to counsel women who are considering TOLAC.

Cesarean scar disorder: Management and repair

Cesarean scar disorder (CSD) is an entity recently defined as uterine niche with at least one primary or 2 secondary symptoms. CSDs can be visualized by hysterosalpingography, transvaginal sonography, saline infusion sonohysterography, hysteroscopy, and magnetic resonance imaging, but diagnosis should be performed by exams able to measure the residual myometrial thickness (RMT). Although there is a limited number of studies evaluating fertility and reproductive outcomes after different types of surgery, the following consideration should be kept in mind. Asymptomatic women should not be operated with the hope of improving obstetrical outcomes. It is reasonable to consider hormone therapy for CSDs as a symptomatic treatment in women who no longer wish to conceive and have no contraindications. In case of failure of or contraindications to medical treatment, surgery should be offered according to the severity of symptoms, including infertility, the desire or otherwise to preserve the uterus, the size of the CSD, and RMT measurement. Hysteroscopy is considered to be more of a resection than a repair, so women who desire pregnancy should be excluded from this technique in case of RMT <3 mm. In this instance, repair is essential and can only be achieved by a laparoscopic or vaginal approach. The benefit of laparoscopic approach seems to persist after subsequent CS. Women with CSDs need to be given complete information, including available literature, before any treatment decision is made.

Effectiveness of laparoscopic niche resection versus expectant management in patients with unexplained infertility and a large uterine caesarean scar defect (uterine niche): protocol for a randomised controlled trial (the LAPRES study)

INTRODUCTION

A uterine niche is a defect at the site of the uterine caesarean scar that is associated with gynaecological symptoms and infertility. Promising results are reported in cohort studies after a laparoscopic niche resection concerning reduction of gynaecological symptoms in relation to baseline and concerning pregnancy outcomes. However, randomised controlled trials to study the effect of a laparoscopic niche resection on reproductive outcomes in infertile women are lacking. This study will answer the question if laparoscopic niche resection in comparison to expectant management improves reproductive outcomes in infertile women with a large uterine niche.

METHODS AND ANALYSIS

The LAPRES study is a randomised, non-blinded, controlled trial, including 200 infertile women with a total follow-up of 2 years. Women with the presence of a large niche in the uterine caesarean scar and unexplained infertility of at least 1 year or failed IVF will be randomly allocated to a laparoscopic niche resection within 6 weeks or to expectant management for at least 9 months. A large niche is defined as a niche with a depth of >50% of the myometrial thickness and a residual myometrium of ≤3 mm on transvaginal ultrasound. Those receiving expectant management will be allowed to receive fertility therapies, including assisted reproductive techniques, if indicated. The primary outcome is time to ongoing pregnancy, defined as a viable intrauterine pregnancy at 12 weeks' gestation. Secondary outcome measures are time to conception leading to a live birth, other pregnancy outcomes, received fertility therapies after randomisation, menstruation characteristics, patient satisfaction, quality of life, additional interventions, and surgical and ultrasound outcomes (intervention group). Questionnaires will be filled out at baseline, 6, 12 and 24 months after randomisation. Ultrasound evaluation will be performed at baseline and at 3 months after surgery.

ETHICS AND DISSEMINATION

The study protocol was approved by the medical ethics committee of the Amsterdam University Medical Centre. (Ref. No. 2017.030). Participants will sign a written informed consent before participation. The results of this study will be submitted to a peer-reviewed journal for publication. TRIAL REGISTRATION NUMBER DUTCH TRIAL REGISTER REF NO NL6350 : http://www.trialregister.nl.

New ultrasonographic risk assessment of uterine scar dehiscence in pregnancy after cesarean section

PURPOSE

We performed a new ultrasonographic risk assessment of uterine scar dehiscence, which is a potential risk factor for uterine rupture, in pregnancy after cesarean section. We attempted to shed light on the natural course of the change in the lower uterine segment by means of a longitudinal investigation through quantitative and qualitative evaluations.

METHODS

This retrospective single-center study involved 31 women with a normal singleton pregnancy delivered by elective cesarean section between 2020 and 2021, with all women showing a "niche" in the lower uterine segments. The lower uterine segments were assessed qualitatively and quantitatively using transvaginal ultrasonography at 16-21, 22-27, and 28-33 weeks of gestation, and subjects were divided into two groups: those with uterine dehiscence (12 women) and those without uterine dehiscence (19 women), depending on the gross findings of the lower uterine segments at cesarean section. Analyses were performed using Wilcoxon's rank-sum and Mann-Whitney U test with a significance level of P < 0.05.

RESULTS

The lower uterine segments changed from V-shaped to U-shaped to thin as gestation progressed and was more prominent in the uterine dehiscence group, occurring mostly at 22-27 weeks. At 22-27 weeks, the median myometrial thickness in the uterine dehiscence group was lower than in the group without uterine dehiscence (P = 0.0030). Thinning of the lower uterine segments had moved the cephalad at 22-27 and 28-33 weeks in cases with and without uterine dehiscence.

CONCLUSION

A model of morphological changes in the niche was constructed based on qualitative and quantitative assessments. The morphological changes and actual thinning of the lower uterine segments were prominent in the second trimester in women considered to have uterine scar dehiscence.

Outcomes and risk factors for failed trial of labor after cesarean delivery (TOLAC) in women with one previous cesarean section: a Chinese population-based study

Objective

To evaluate the outcomes and risk factors for trial of labor after cesarean delivery (TOLAC) failure in patients in China.

Methods

Consecutive patients who had a previous cesarean delivery (CD) and attempted TOLAC were included from 2014 to 2020. Patients who successfully delivered were classified into the TOLAC success group. Patients who attempted TOLAC but had a repeat CD due to medical issues were classified into the TOLAC failure group. Multiple logistic regression analyses were performed to examine the risk factors for TOLAC failure.

Results

In total, 720 women who had a previous CD and attempted TOLAC were identified and included. The success rate of TOLAC was 84.2%(606/720). Seven patients were diagnosed with uterine rupture, none of whom underwent hysterectomy. Multiple logistic regression analysis showed that the induction of labor (OR = 2.843, 95% CI: 1.571–5.145, P < 0.001) was positively associated with TOLAC failure, but the thickness of the lower uterine segment (LUS) (OR = 0.215, 95% CI: 0.103–0.448, P < 0.001) was negatively associated with TOLAC failure.

Conclusions

This study suggested that TOLAC was effective in decreasing CD rates in the Chinese population. The induction of labor was positively associated with TOLAC failure, but the thickness of the LUS was negatively associated with TOLAC failure. Our findings need to be confirmed in larger samples with patients of different ethnicities.

Nationwide implementation of a decision aid on vaginal birth after cesarean: a before and after cohort study

OBJECTIVES

Woman with a history of a previous cesarean section (CS) can choose between an elective repeat CS (ERCS) and a trial of labor (TOL), which can end in a vaginal birth after cesarean (VBAC) or an unplanned CS. Guidelines describe women's rights to make an informed decision between an ERCS or a TOL. However, the rates of TOL and vaginal birth after CS varies greatly between and within countries. The objective of this study is to asses nation-wide implementation of counselling with a decision aid (DA) including a prediction model, on intended delivery compared to care as usual. We hypothesize that this may result in a reduction in practice variation without an increase in cesarean rates or complications.

METHODS

In a multicenter controlled before and after cohort study we evaluate the effect of nation-wide implementation of a DA. Practice variation was defined as the standard deviation (SD) of TOL percentages.

RESULTS

A total of 27 hospitals and 1,364 women were included. A significant decrease was found in practice variation (SD TOL rates: 0.17 control group vs. 0.10 intervention group following decision aid implementation, p=0.011). There was no significant difference in the ERCS rate or overall CS rates. A 21% reduction in the combined maternal and perinatal adverse outcomes was seen.

CONCLUSIONS

Nationwide implementation of the DA showed a significant reduction in practice variation without an increase in the rate of cesarean section or complications, suggesting an improvement in equality of care.

[Cesarean scare niche: Definition, diagnosis, risk factors, prevention, symptoms, adverse effects, and treatments]

OBJECTIVES

To review the definitions, diagnostic methods, risk factors, symptoms, and treatments for caesarean scar niche.

METHODS

Review of the literature, critical reflection, and pragmatic advice.

RESULTS

There is no consensus on the definition of caesarean scar niche. Some suggest an indentation≥2mm of the myometrium of the caesarean scar, but this is present in more than half of women with caesarean history and takes no account of woman's symptoms. The most popular diagnostic method is ultrasound±hysterosonography. Risks factors for niche are multiple Caesareans, Cesarean during labor with too low incision, and retroverted uterus. Symptoms include abnormal gynaecologic bleeding and pelvic pain, and their presence establish the "Caesarean scar syndrome". The risks of pregnancy with niche is poorly studied, but pregnancy is not contraindicated, even if the niche is untreated. The treatment of caesarean scar niche is mainly surgery and conservative. The former should be reserved for symptomatic patients, and those with secondary infertility and fertility treatment failure. Patients with residual myometrium thickness≥2.5mm may benefit from first-line hysteroscopic treatment, whereas a laparoscopic or vaginal approach could be offered in other cases.

CONCLUSIONS

A pragmatic definition of caesarean scar niche as a disease including symptoms is the necessary prerequisite for the management of women. The treatment is mainly surgical, or conservative depending on the desire for subsequent pregnancy.

Mechanical Effects of a Maylard Scar During a Vaginal Birth After a Previous Caesarean

Caesarean section is one of the most common surgeries worldwide, even though there is no evidence supporting maternal and perinatal long-term benefits. Furthermore, the mechanical behavior of a caesarean scar during a vaginal birth after caesarean (VBAC) is not well understood since there are several questions regarding the uterine wound healing process. The aim of this study is to investigate the biomechanical Maylard fiber reorientation and stiffness influence during a VBAC through computational methods. A biomechanical model comprising a fetus and a uterus was developed, and a chemical-mechanical constitutive model that triggers uterine contractions was used, where some of the parameters were adjusted to account for the matrix and fiber stiffness increase in the caesarean scar. Several mechanical simulations were performed to analyze different scar fibers arrangements, considering different values for the respective matrix and fibers stiffness. The results revealed that a random fiber arrangement in the Maylard scar has a much higher impact on its mechanical behavior during a VBAC than the common fibers arrangement present in the uninjured uterine tissue. An increase of the matrix scar stiffness exhibits a lower impact, while an increase of the fiber's stiffness has no significant influence.

Reduced pregnancy and live birth rates after in vitro fertilization in women with previous Caesarean section: a retrospective cohort study

STUDY QUESTION

Does a previous Caesarean section affect reproductive outcomes, including live birth, in women after IVF or ICSI?

SUMMARY ANSWER

A previous Caesarean section impairs live birth rates after IVF or ICSI compared to a previous vaginal delivery.

WHAT IS KNOWN ALREADY

Rates of Caesarean sections are rising worldwide. Late sequelae of a Caesarean section related to a niche (Caesarean scar defect) include gynaecological symptoms and obstetric complications. A systematic review reported a lower pregnancy rate after a previous Caesarean section (RR 0.91 CI 0.87–0.95) compared to a previous vaginal delivery. So far, studies have been unable to causally differentiate between problems with fertilisation, and the transportation or implantation of an embryo. Studying an IVF population allows us to identify the effect of a previous Caesarean section on the implantation of embryos in relation to a previous vaginal delivery.

STUDY DESIGN, SIZE, DURATION

We retrospectively studied the live birth rate in women who had an IVF or ICSI treatment at the IVF Centre, Amsterdam UMC, location VUmc, Amsterdam, the Netherlands, between 2006 and 2016 with one previous delivery. In total, 1317 women were included, of whom 334 had a previous caesarean section and 983 had previously delivered vaginally.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All secondary infertile women, with only one previous delivery either by caesarean section or vaginal delivery, were included. If applicable, only the first fresh embryo transfer was included in the analyses. Patients who did not intend to undergo embryo transfer were excluded. The primary outcome was live birth. Multivariate logistic regression analyses were used with adjustment for possible confounders ((i) age; (ii) pre-pregnancy BMI; (iii) pre-pregnancy smoking; (iv) previous fertility treatment; (v) indication for current fertility treatment: (a) tubal, (b) male factor and (c) endometriosis; (vi) embryo quality; and (vii) endometrial thickness), if applicable. Analysis was by intention to treat (ITT).

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline characteristics of both groups were comparable. Live birth rates were significantly lower in women with a previous caesarean section than in women with a previous vaginal delivery, 15.9% (51/320) versus 23.3% (219/941) (OR 0.63 95% CI 0.45–0.87) in the ITT analyses. The rates were also lower for ongoing pregnancy (20.1 versus 28.1% (OR 0.64 95% CI 0.48–0.87)), clinical pregnancy (25.7 versus 33.8% (OR 0.68 95% CI 0.52–0.90)) and biochemical test (36.2 versus 45.5% (OR 0.68 95% CI 0.53–0.88)). The per protocol analyses showed the same differences (live birth rate OR 0.66 95% CI 0.47–0.93 and clinical pregnancy rate OR 0.72 95% CI 0.54–0.96).

LIMITATIONS, REASONS FOR CAUTION

This study is limited by its retrospective design. Furthermore, 56 (16.3%) cases lacked data regarding delivery outcomes, but these were equally distributed between the two groups.

WIDER IMPLICATIONS OF THE FINDINGS

The lower clinical pregnancy rates per embryo transfer indicate that implantation is hampered after a caesarean section. Its relation with a possible niche (caesarean scar defect) in the uterine caesarean scar needs further study. Our results should be discussed with clinicians and patients who consider an elective caesarean section.

STUDY FUNDING/COMPETING INTEREST(S)

Not applicable.

TRIAL REGISTRATION NUMBER

This study has been registered in the Dutch Trial Register (Ref. No. NL7631 http://www.trialregister.nl).

Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased

Around 20% of pregnant women undergo cesarean section (CS), and in most regions of the world CS rates continue to grow. There is still no clear definition of what is considered a normal physiologic aspect of a CS scar and what is abnormal. Cesarean scar defects (CSDs) should be suspected in women presenting with spotting, dysmenorrhea, pelvic pain, or infertility and a history of CS. CSDs can be visualized with the use of hysterosalpingography, transvaginal sonography, saline infusion sonohysterography, hysteroscopy, and magnetic resonance imaging. It is reasonable to consider hormone therapy for CSDs as a symptomatic treatment in women who no longer wish to conceive and have no contraindications. In case of failure of or contraindications to medical treatment, surgery should be contemplated according to the severity of symptoms, including infertility, the desire or otherwise to preserve the uterus, the size of the CSD, and residual myometrium thickness (RMT) measurement. Hysteroscopy is considered to be more of a resection than a repair, so women who desire pregnancy should be excluded from this technique if the RMT is <3 mm, in which case repair is essential and can be achieved by only laparoscopic or vaginal approach. Women with CSDs need to be given complete information, including available literature, before any treatment decision is made. Because prevention is better than cure, risk factors should be identified early to ensure appropriate management.

Prediction of vaginal birth after cesarean delivery in Southeast China: a retrospective cohort study

BACKGROUND

We aimed to develop and validate a nomogram for effective prediction of vaginal birth after cesarean (VBAC) and guide future clinical application.

METHODS

We retrospectively analyzed data from hospitalized pregnant women who underwent trial of labor after cesarean (TOLAC), at the Fujian Provincial Maternity and Children's Hospital, between October 2015 and October 2017. Briefly, we included singleton pregnant women, at a gestational age above 37 weeks who underwent a primary cesarean section, in the study. We then extracted their sociodemographic data and clinical characteristics, and randomly divided the samples into training and validation sets. We employed the least absolute shrinkage and selection operator (LASSO) regression to select variables and construct VBAC success rate in the training set. Thereafter, we validated the nomogram using the concordance index (C-index), decision curve analysis (DCA), and calibration curves. Finally, we adopted the Grobman's model to perform comparisons with published VBAC prediction models.

RESULTS

Among the 708 pregnant women included according to inclusion criteria, 586 (82.77%) patients were successfully for VBAC. Multivariate logistic regression models revealed that maternal height (OR, 1.11; 95% CI, 1.04 to 1.19), maternal BMI at delivery (OR, 0.89; 95% CI, 0.79 to 1.00), fundal height (OR, 0.71; 95% CI, 0.58 to 0.88), cervix Bishop score (OR, 3.27; 95% CI, 2.49 to 4.45), maternal age at delivery (OR, 0.90; 95% CI, 0.82 to 0.98), gestational age (OR, 0.33; 95% CI, 0.17 to 0.62) and history of vaginal delivery (OR, 2.92; 95% CI, 1.42 to 6.48) were independently associated with successful VBAC. The constructed predictive model showed better discrimination than that from the Grobman's model in the validation series (c-index 0.906 VS 0.694, respectively). On the other hand, decision curve analysis revealed that the new model had better clinical net benefits than the Grobman's model.

CONCLUSIONS

VBAC will aid in reducing the rate of cesarean sections in China. In clinical practice, the TOLAC prediction model will help improve VBAC's success rate, owing to its contribution to reducing secondary cesarean section.

Prediction of Delivery Complications by First-Trimester Ultrasound Measurement of the Gestational Sac's Distance From a Previous Cesarean Section Scar

OBJECTIVES

This study was designed to investigate the clinical relationship between labor complications in the second and third trimesters and the distance from the gestational sac to a previous cesarean section (CS) scar.

METHODS

We conducted a retrospective review of the electronic medical records and included all 7- to 9-week transvaginal ultrasound examination reports from pregnancies with a history of a single cesarean delivery in our hospital between January 2015 and December 2017. Women were divided into 6 groups according to the distance of the gestational sac to the CS scar (groups A-F). A composite of pregnancy outcomes (gestational age at birth, delivery mode, placental abnormality, blood loss, uterine rupture, and hysterectomy) and other maternal and neonatal outcomes were assessed.

RESULTS

A total of 699 cases were included in our study. The median gestational age was 39.0 (range, 38.1-39.9) weeks. The median intrapartum blood loss volume was 400 (range, 300-500) mL. The results showed no statistically significant difference in blood loss (P = .297) or birth weight of the neonate (P = .318) among the distance subgroups. Overall, the fetuses were stillborn in 9 of 699 cases (1.29%). There was a statistically significant difference in a morbidly adherent placenta, placenta previa, and preterm labor, and their incidence increased with decreasing distance (P < .001; P for trend < .05). There was no statistically significant difference in uterine rupture (P = .597) or the delivery mode (P = .187) among the subgroups.

CONCLUSIONS

The relative positions of a CS scar and the gestational sac in the first trimester are associated with the incidence of placental abnormalities. As the distance decreases, the extent of a morbidly adherent placenta increases.

Laparoscopic repair of uterine rupture following successful second vaginal birth after caesarean delivery: A case report

BACKGROUND

With the increasing trend of vaginal birth after caesarean delivery (VBAC), evaluation of the feasibility and safety of a second VBAC with grand multiparity is worth considering. Intrapartum uterine rupture is diagnosed in approximately one-fifth of all VBAC cases following successful vaginal delivery. To our knowledge, no report is available on the application of laparoscopy to repair postpartum uterine rupture after a successful second VBAC in China.

CASE SUMMARY

A 31-year-old woman (gravida 5, para 2) at 39 wk and 5 d of gestation was admitted to the hospital in labour. After a successful VBAC and observation for approximately 13 h, the patient complained of progressive abdominal pain. Given the symptoms, signs, and auxiliary examination results, intraperitoneal bleeding was considered. Because the patient was stable and ultrasound imaging was the only method available to assess the possibility of rupture, we recommended laparoscopy to clarify the diagnosis and for prompt laparoscopic uterine repair or exploratory laparotomy if necessary. Operative findings included transverse uterine scar rupture at the lower uterine segment of approximately 5.0 cm in length and 800 mL of intraoperative pelvic haemoperitoneum. Finally, she successfully underwent laparoscopic repair of uterine rupture and recovered very well according to three-dimensional magnetic resonance imaging at 42 d postpartum.

CONCLUSION

Routine postpartum intrauterine exploration is not beneficial to the mother and may even increase the risk of rupture. This case highlights a laparoscopic approach for repairing uterine rupture in the immediate postpartum period.

Cesarean scar thickness in non-pregnant women as a risk factor for uterine rupture

Introduction: Whether there is an association between residual myometrial thickness (RMT) after cesarean section (CS) and the risk of uterine rupture (UR) or uterine scar dehiscence at the subsequent delivery has been sparsely investigated.Materials and methods: Our cohort included 149 women with a first CS in whom we measured RMT by transvaginal ultrasonography 6-15 months after their delivery. We did a follow-up study on delivery outcomes in the women's subsequent births. The exposure was scar measurements in the non-pregnant uterus, and the primary outcome was a diagnosis of UR or dehiscence. We calculated likelihood ratios (LRs) with 95% confidence intervals of having UR or dehiscence with a thin RMT (<3 mm).Results: Among the 149 women, 39 had a repeat CS (14 scheduled and 25 unscheduled procedures), and within these, we found one woman with UR and five women with uterine dehiscence. The proportion of women with a thin RMT was significantly higher among cases (4/6) than in controls (4/33); the LR was 5.5 (95% CI 1.9-16.2).Conclusions: The results suggest a significant association between a thin RMT as measured by transvaginal ultrasonography in the non-pregnant uterus after a first scheduled CS and the risk of UR or dehiscence at a subsequent delivery.

The Failure Rate, Related Factors, and Neonate Complications of Vaginal Delivery after Cesarean Section

Background

The rate of Cesarean Section (CS) is high in Iran. A successful Vaginal Birth After Cesarean (VBAC) section can protect mothers against the risk of having multiple CS. This study aimed to evaluate the success rate of VBAC, related factors, and the causes of failure.

Materials and Methods

This cross-sectional study was conducted on 150 pregnant women who were candidates for VBAC and admitted at maternity hospitals in Qom from 2016 to 2018. The required data were collected from the patients' records and entered into the checklist. Then, the success rate of VBAC was estimated, and related factors together with the causes of failure were determined by t-test, Chi-square, and independent-samples t-tests in SPSS v. 18 software.

Results

The mean (SD) maternal age was 32 (5.20) years and ranged from 21 to 45 years old. The success rate of VBAC was estimated to be 85.33%, and 14.67% of the patients had to repeat a CS after failure in vaginal delivery. The mean time between previous CS and present delivery was statistically significant between successful and failure groups (t ₁₂₅ = 2.32, p = 0.002). The results also revealed that the most important causes of VBAC failure were prolonged labor [odds ratio (OR) = 4.70)], full arrest (OR = 2.70), and decline fetal heart (OR = 5.31).

Conclusions

The success rate of VBAC in our study was high. However, VBAC was more successful when the interval between inter-deliveries was long, and lower complications were reported when the interval was 2-4 years.

Factors associated with successful vaginal birth after a cesarean section: a systematic review and meta-analysis

Background

Evidence for the relationship between maternal and perinatal factors and the success of vaginal birth after cesarean section (VBAC) is conflicting. We aimed to systematically analyze published data on maternal and fetal factors for successful VBAC.

Methods

A comprehensive search of Medline, Embase, and the Cumulative Index to Nursing and Allied Health Literature, from each database’s inception to March 16, 2018. Observational studies, identifying women with a trial of labor after one previous low-transverse cesarean section were included. Two reviewers independently abstracted the data. Meta-analysis was performed using the random-effects model. Risk of bias was assessed by the Newcastle-Ottawa Scale.

Results

We included 94 eligible observational studies (239,006 pregnant women with 163,502 VBAC). Factors were associated with successful VBAC with the following odds ratios (OR;95%CI): age (0.92;0.86–0.98), obesity (0.50;0.39–0.64), diabetes (0.50;0.42–0.60), hypertensive disorders complicating pregnancy (HDCP) (0.54;0.44–0.67), Bishop score (3.77;2.17–6.53), labor induction (0.58;0.50–0.67), macrosomia (0.56;0.50–0.64), white race (1.39;1.26–1.54), previous vaginal birth before cesarean section (3.14;2.62–3.77), previous VBAC (4.71;4.33–5.12), the indications for the previous cesarean section (cephalopelvic disproportion (0.54;0.36–0.80), dystocia or failure to progress (0.54;0.41–0.70), failed induction (0.56;0.37–0.85), and fetal malpresentation (1.66;1.38–2.01)). Adjusted ORs were similar.

Conclusions

Diabetes, HDCP, Bishop score, labor induction, macrosomia, age, obesity, previous vaginal birth, and the indications for the previous CS should be considered as the factors affecting the success of VBAC.

The effect of the use of a decision aid with individual risk estimation on the mode of delivery after a caesarean section: A prospective cohort study

Objective

After one previous caesarean section (CS), pregnant women can deliver by elective repeat CS or have a trial of labor which can end in a vaginal birth after caesarean (VBAC) or an unplanned CS. Despite guidelines describing women’s rights to make an informed choice, trial of labor and VBAC rates vary greatly worldwide. Many women are inadequately informed due to caregivers’ fear of an increase in CS rates in a high VBAC rate setting. We compared counseling with a decision aid (DA) including a prediction model on VBAC to care as usual. We hypothesize that counselling with the DA does not decrease VBAC rates. In addition, we aimed to study the effects on unplanned CS rate, patient involvement in decision-making and elective repeat CS rates.

Methods

We performed a prospective cohort study. From 2012 to 2014, 483 women in six hospitals, where the DA was used (intervention group), were compared with 441 women in six matched hospitals (control group). Women with one previous CS, pregnant of a singleton in cephalic presentation, delivering after 37 weeks 0 days were eligible for inclusion.

Results

There was no significant difference in VBAC rates between the intervention (45%) and control group (46%) (adjusted odds ratio 0,92 (95% Confidence interval 0.69–1.23)). In the intervention group more women (42%) chose an elective repeat CS compared to the control group (31%) (adjusted odds ratio 1.6 (95% Confidence interval 1.18–2.17)). Of women choosing trial of labor, in the intervention group 77% delivered vaginally compared to 67% in the control group, resulting in an unplanned CS adjusted odds ratio of 0,57 (0.40–0.82) in the intervention group. In the intervention group, more women reported to be involved in decision-making (98% vs. 68%, P< 0.001).

Conclusions

Implementing a decision aid with a prediction model for risk selection suggests unchanged VBAC rates, but 40% reduction in unplanned CS rates, increase in elective repeat CS and improved patient involvement in decision-making.

Single- versus double-layer closure of the caesarean (uterine) scar in the prevention of gynaecological symptoms in relation to niche development - the 2Close study: a multicentre randomised controlled trial

BACKGROUND

Double-layer compared to single-layer closure of the uterus after a caesarean section (CS) leads to a thicker myometrial layer at the site of the CS scar, also called residual myometrium thickness (RMT). It possibly decreases the development of a niche, which is an interruption of the myometrium at the site of the uterine scar. Thin RMT and a niche are associated with gynaecological symptoms, obstetric complications in a subsequent pregnancy and delivery and possibly with subfertility.

METHODS

Women undergoing a first CS regardless of the gestational age will be asked to participate in this multicentre, double blinded randomised controlled trial (RCT). They will be randomised to single-layer closure or double-layer closure of the uterine incision. Single-layer closure (control group) is performed with a continuous running, unlocked suture, with or without endometrial saving technique. Double-layer closure (intervention group) is performed with the first layer in a continuous unlocked suture including the endometrial layer and the second layer is also continuous unlocked and imbricates the first. The primary outcome is the reported number of days with postmenstrual spotting during one menstrual cycle nine months after CS. Secondary outcomes include surgical data, ultrasound evaluation at three months, menstrual pattern, dysmenorrhea, quality of life, and sexual function at nine months. Structured transvaginal ultrasound (TVUS) evaluation is performed to assess the uterine scar and if necessary saline infusion sonohysterography (SIS) or gel instillation sonohysterography (GIS) will be added to the examination. Women and ultrasound examiners will be blinded for allocation. Reproductive outcomes at three years follow-up including fertility, mode of delivery and complications in subsequent deliveries will be studied as well. Analyses will be performed by intention to treat. 2290 women have to be randomised to show a reduction of 15% in the mean number of spotting days. Additionally, a cost-effectiveness analysis will be performed from a societal perspective.

DISCUSSION

This RCT will provide insight in the outcomes of single- compared to double-layer closure technique after CS, including postmenstrual spotting and subfertility in relation to niche development measured by ultrasound.

TRIAL REGISTRATION

Dutch Trial Register ( NTR5480 ). Registered 29 October 2015.

Cesarean scar defect- obstetric consequences

Scope. This review aims to achieve a parallelism between literature studies on imaging diagnosis, the characteristics of cesarean scar defect and its evolution during pregnancy, and the obstetric consequences that can lead to increased maternal morbidity. Materials and Methods. There have been many literature studies published in recent years aimed to identify the methods of diagnosis for cesarean scar defect, the characteristics and the main changes of it during pregnancy, and the risks undertaken by pregnant women undergoing labor for vaginal delivery after a previous cesarean surgery. Results and Discussions. The most commonly used method for visualizing and evaluating uterine scar is transvaginal ultrasound in the first trimester of pregnancy, and abdominal ultrasonography in the II and III trimesters. The two areas characteristic of uterine scarring: "niche" and "thickness of the residual myometrium" undergo changes during the three trimesters of pregnancy. Some studies in the literature reported a higher incidence of uterine rupture, especially when the lower uterine segment fell below 2.3 mm, and a mean thickness of 3.2 mm, higher among multiparous women. A question that still does not have a generally valid answer refers to the hysterorrhaphy technique. There are different opinions among the authors, but most of them consider that after a double layer suture the thickness of the residual myometrium is higher. However, data from the literature show that the incidence of complications such as uterine rupture, dehiscence of the uterine trance are similar, regardless of the type of suture used. Another complication that occurs due to uterine scar is the pregnancy inserted at this level, which in the case of expectancy, leads to an increase in maternal and fetal morbidity. 50% of them evolve to spontaneous abortion in the first trimester, and almost all full-term pregnancies result in hysterectomy of necessity. Conclusions. Due to the many obstetrical and gynecological complications that occur on a uterine scar, an evaluation in dynamics is essential. There are no standardized protocols yet, but the identification and measurement of the uterine scar area in the third trimester may predict the chance of success of the labor test for vaginal delivery after cesarean surgery.

Etiology of Cesarean Uterine Scar Defect (Niche): Detailed Critical Analysis of Hypotheses and Prevention Strategies and Peritoneal Closure Debate

There is an increasing incidence of cesarean scar (CS) defect/niche and its sequelae, probably not entirely explained by better diagnosis or rising cesarean rate. Discussion of possible etiological factors has received scant attention but would be important to formulate preventive strategies. Meaningful informative studies on long-term sequelae of cesarean section are very difficult and none are available for causation of CS defect. Hence, it is crucial to identify key areas in etiology of CS defect for focused research. This practical review proposes an "ischemia and mal-apposition hypothesis for CS niche", stating that the surgical technique of uterine incision closure is the most important determinant of CS defect formation. Other factors such as cervical location incision, adhesion formation and patient specific factors seem far less important in etiology. Rather than the headline theme of "single versus double-layer closure of uterus", the finer details of surgical technique which achieve good apposition without inducing tissue ischemia seem more important. Different techniques are discussed and it is proposed that continuous, non-locking absorbable sutures in two layers, without including much of decidua and without undue tight (constricting/devasculaizing) pulling of sutures are likely to result in good healing of uterine scar. Single-layer technique may be best reserved for thin myometrial edges especially during repeat cesareans. Adhesions between uterine isthmus and bladder/abdominal wall seem common associations but not causative for CS niche. It would be desirable to prove these surgical principles by good quality prospective randomized "quantitative" studies but the wait may be very long and this should not hinder the adoption of good surgical principles. Science is much cognitive and not just empirical. To consider a related example, the current recommendation of non-suturing of peritoneal layers during cesarean is mistakenly based on short-term irrelevant surrogate outcomes like analgesic requirements and time-saving, many of which have been already disproven. Evidence is presented recommending simple quick techniques of peritoneal closure to prevent adhesions. More analytical debate in surgical techniques is needed to inspire engaged, critical and insightful practitioners rather than unquestioning dependence on weak evidence/guidance.

Validation of prediction model for successful vaginal birth after Cesarean delivery based on sonographic assessment of hysterotomy scar

OBJECTIVE

To validate a prediction model for successful vaginal birth after Cesarean delivery (VBAC) based on sonographic assessment of the hysterotomy scar, in a Swedish population.

METHODS

Data were collected from a prospective cohort study. We recruited non-pregnant women aged 18-35 years who had undergone one previous low-transverse Cesarean delivery at ≥ 37 gestational weeks and had had no other uterine surgery. Participants who subsequently became pregnant underwent transvaginal ultrasound examination of the Cesarean hysterotomy scar at 11 + 0 to 13 + 6 and at 19 + 0 to 21 + 6 gestational weeks. Thickness of the myometrium at the thinnest part of the scar area was measured. After delivery, information on pregnancy outcome was retrieved from hospital records. Individual probabilities of successful VBAC were calculated using a previously published model. Predicted individual probabilities were divided into deciles. For each decile, observed VBAC rates were calculated. To assess the accuracy of the prediction model, receiver-operating characteristics curves were constructed and the areas under the curves (AUC) were calculated.

RESULTS

Complete sonographic data were available for 120 women. Eighty (67%) women underwent trial of labor after Cesarean delivery (TOLAC) with VBAC occurring in 70 (88%) cases. The scar was visible in all 80 women at the first-trimester scan and in 54 (68%) women at the second-trimester scan. AUC was 0.44 (95% CI, 0.28-0.60) among all women who underwent TOLAC and 0.51 (95% CI, 0.32-0.71) among those with the scar visible sonographically at both ultrasound examinations.

CONCLUSION

The prediction model demonstrated poor accuracy for prediction of successful VBAC in our Swedish population. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Uterine caesarean closure techniques affect ultrasound findings and maternal outcomes: a systematic review and meta-analysis

BACKGROUND

Caesarean section (CS) rates are rising globally. Long-term adverse outcomes after CS might be reduced when the optimal uterine closure technique becomes evident.

OBJECTIVE

To determine the effect of uterine closure techniques after CS on maternal and ultrasound outcomes.

SEARCH STRATEGY

Literature search in electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or prospective cohort studies that evaluated uterine closure techniques and reported on ultrasound findings, perioperative or long-term outcomes.

DATA COLLECTION AND ANALYSIS

Twenty studies (15 053 women) were included in our meta-analyses for various outcomes. We calculated pooled risk ratios (RR) and weighted mean differences (WMD) with 95% CI through random-effect analysis.

MAIN RESULTS

Residual myometrium thickness (RMT), reported in eight studies (508 women), decreased by 1.26 mm after single- compared with double-layer closure (95% CI -1.93 to -0.58), particularly when locked sutures were used. Healing ratio [RMT/adjacent myometrium thickness (AMT)] decreased after single-layer closure (WMD -7.74%, 95% CI -13.31 to -2.17), particularly in the case of locked sutures. Niche prevalence increased (RR 1.71, 95% CI 1.11-2.62) when the decidua was excluded. Dysmenorrhea occurred more often in the single-layer group (RR 1.23, 95% CI 1.01-1.48), whereas incidence of uterine rupture was similar (RR 1.91, 95% CI 0.63-5.74).

CONCLUSION

Double-layer unlocked sutures are preferable to single-layer locked sutures regarding RMT, healing ratio and dysmenorrhoea. Excluding the decidua seems to result in higher niche prevalence. As thin residual myometrium or niches may serve as intermediates for gynaecological and reproductive outcomes, future studies should focus on these outcomes. TWEETABLE ABSTRACT: #Uterineclosuretechniques after #caesarean affect #longtermoutcomes.

Sonographic evaluation of surgical repair of uterine cesarean scar defects

BACKGROUND

The aim of the study was to assess the clinical outcomes of surgical repair of uterine cesarean scar defects with sonography (US).

METHODS

Seven nonpregnant women with history of cesarean section and a large uterine scar defect were enrolled. The surgical repair was performed by minilaparotomy. The US assessment of the uterine scar was performed using a standardized approach at baseline, then at a first visit 2-3 days following the surgical intervention (V1) and at a follow-up visit 3 months later (V2). Residual myometrial thickness (RMT), width, and depth of the scar defect were measured.

RESULTS

The mean RMT increased significantly from 1.9 mm at baseline to 8.8 mm at V1 and 8.0 mm at V2. No intraoperative complications were observed. Postmenstrual spotting and abdominal pain reported preoperatively resolved after the operation.

CONCLUSIONS

A surgical repair procedure for an incompletely healed uterine cesarean scar is effective in increasing RMT thickness, decreasing the depth of the scar, and reducing symptoms related to the cesarean section scar defect. Further studies on post-repair pregnancy outcomes are required to evaluate whether the procedure affects the rate of cesarean scar pregnancy, morbidly adherent placenta, and/or uterine scar dehiscence and rupture. The repair of a cesarean scar defect is recommended only for symptomatic women. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:455-460, 2017.

Pilot study of MRI/ultrasound fusion imaging in postpartum assessment of Cesarean section scar

OBJECTIVE

To evaluate prospectively the uterine scar after Cesarean section (CS) and the corresponding uterine region after vaginal delivery (VD) at 6 weeks postpartum using transabdominal (TAS) and transvaginal (TVS) sonography with magnetic resonance imaging (MRI) fusion to investigate whether fusion imaging allows standardized and reproducible identification of the scar location and measurement of uterine wall thickness compared with high-resolution MRI alone.

METHODS

Pelvic MRI was performed 6 weeks after delivery in 30 women (10 with planned CS (PCS), 10 with emergency CS (ECS) and 10 with VD). After transfer of MRI-DICOM datasets to the ultrasound system, the scar region after CS and the corresponding uterine region after VD were examined by TAS (5 MHz) and TVS (10 MHz) using smart fusion with MRI to guide visualization of the region in the corresponding sectional planes for both modalities. Vascularization of the scar region was determined as a percentage area using power Doppler ultrasound. Anterior (AW) and posterior (PW) uterine wall thickness was measured using TAS and TVS with fusion imaging and using MRI alone.

RESULTS

TVS with fusion imaging was applied successfully for uterine assessment at the end of the postpartum period in all women. TAS failed to identify the scar area in three women. Imaging techniques were similar in the evaluation of AW and PW thickness following VD. MRI and MRI/TVS fusion showed significant differences in AW thickness or scar area, in terms of the difference relative to PW thickness, in women with PCS and ECS (MRI: PCS, 4.3 mm; ECS, 4.2 mm; VD, 0.8 mm; P = 0.034; MRI/TVS fusion: PCS, 2.0 mm; ECS, 3.3 mm; VD, 0.0 mm; P = 0.01). The degree of vascularization in the scar region measured by power Doppler ultrasound was lower after PCS (13.1 ± 9.4%/area) and ECS (17.0 ± 8.2%/area) than after VD (34.6 ± 8.5%/area; P = 0.0017).

CONCLUSION

MRI/ultrasound fusion imaging can be performed in a reproducible manner for examination of the postpartum uterus. MRI/TVS fusion enables standardized identification of the CS scar location and vascularization is reduced in this area. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

When a cesarean section scar is more than an innocent bystander in a subsequent pregnancy: Ultrasound to the rescue

Over the years, cesarean section has played a pivotal role in reducing maternal and perinatal morbidity and mortality. With the rising trend of this surgery, a substantial number of pregnant women have a cesarean section scar. The scar can serve as the abode of grave conditions in subsequent pregnancies, namely cesarean scar pregnancy, morbidly adherent placenta, and scar dehiscence. Sonography has emerged as a robust tool for the diagnosis of these potentially life-threatening conditions. This review highlights the key sonographic features of various complications that can occur at the cesarean scar site in subsequent pregnancies. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:319-327, 2017.

Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development

Caesarean section (CS) results in the occurrence of the phenomenon 'niche'. A 'niche' describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous CS. Using gel or saline instillation sonohysterography, a niche is identified in the scar in more than half of the women who had had a CS, most with the uterus closed in one single layer, without closure of the peritoneum. An incompletely healed scar is a long-term complication of the CS and is associated with more gynaecological symptoms than is commonly acknowledged. Approximately 30% of women with a niche report spotting at 6-12 months after their CS. Other reported symptoms in women with a niche are dysmenorrhoea, chronic pelvic pain and dyspareunia. Given the association between a niche and gynaecological symptoms, obstetric complications and potentially with subfertility, it is important to elucidate the aetiology of niche development after CS in order to develop preventive strategies. Based on current published data and our observations during sonographic, hysteroscopic and laparoscopic evaluations of niches we postulate some hypotheses on niche development. Possible factors that could play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation or patient-related factors that impair wound healing or increase inflammation or adhesion formation.

A standardized approach for the assessment of the lower uterine segment at first trimester by transvaginal ultrasound: a flash study

OBJECTIVES

To evaluate the reproducibility of a standardized approach to lower uterine segment (LUS) imaging by transvaginal ultrasound at 11-14 weeks.

METHODS

This was a "flash" study lasting for 1 month. Obstetrician-sonographers performing more than 50 first trimester ultrasounds per year participated. All consecutive women attending for their 11-14 weeks scan were included. A standardized, transvaginal approach to the imaging of LUS was defined. The sonographers recorded one or two images of the LUS. The quality of the images was assessed by sonographers and reviewed by an independent fetal medicine specialist using the same scoring system. Inter and intra-reviewer variability was assessed.

RESULTS

Seventy-one sonographers and 851 pregnant women participated. The mean (±SD) and medium (IQR) scores attributed by sonographer versus reviewer were 5.01 (±0.92) and 5 [4-6] versus 4.68 (±1.14) and 5 [4-5.24], p = 0.08. The mean [95% CI] difference of -0.33 [-2.6;2] was recorded. There was good, moderate and poor agreement in 74.4%, 16.7% and 8.9% cases, respectively. Variability in inter-reviewer and intra-reviewer was low with the mean [95% CI] difference of -0.1 [-1.6;1.4] and -0.1 [-1.4;1.2] respectively.

CONCLUSIONS

A standardized approach to LUS imaging at 11-14 weeks is feasible and highly reproducible in a large population.

Vaginal birth after a caesarean section: the development of a Western European population-based prediction model for deliveries at term

OBJECTIVE

To develop and internally validate a model that predicts the outcome of an intended vaginal birth after caesarean (VBAC) for a Western European population that can be used to personalise counselling for deliveries at term.

DESIGN

Registration-based retrospective cohort study.

SETTING

Five university teaching hospitals, seven non-university teaching hospitals, and five non-university non-teaching hospitals in the Netherlands.

POPULATION

A cohort of 515 women with a history of one caesarean section and a viable singleton pregnancy, without a contraindication for intended VBAC, who delivered at term.

METHODS

Potential predictors for a vaginal delivery after caesarean section were chosen based on literature and expert opinions. We internally validated the prediction model using bootstrapping techniques.

MAIN OUTCOME MEASURES

Predictors for VBAC. For model validation, the area under the receiver operating characteristic curve (AUC) for discriminative capacity and calibration-per-risk-quantile for accuracy were calculated.

RESULTS

A total of 371 out of 515 women had a VBAC (72%). Variables included in the model were: estimated fetal weight greater than the 90(th) percentile in the third trimester; previous non-progressive labour; previous vaginal delivery; induction of labour; pre-pregnancy body mass index; and ethnicity. The AUC was 71% (95% confidence interval, 95% CI = 69-73%), indicating a good discriminative ability. The calibration plot shows that the predicted probabilities are well calibrated, especially from 65% up, which accounts for 77% of the total study population.

CONCLUSION

We developed an appropriate Western European population-based prediction model that is aimed to personalise counselling for term deliveries.