Oxytocin use in trial of labor after cesarean and its relationship with risk of uterine rupture in women with one previous cesarean section: a meta-analysis of observational studies

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

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.

Complete rupture of the pregnant uterus: A 12-year retrospective study

OBJECTIVE

To assess the frequency of uterine ruptures, clinical characteristics, and maternal and neonatal outcomes in a tertiary referral center.

METHODS

Information on complete uterine rupture between July 2010 and June 2022 was investigated retrospectively at a tertiary center.

RESULTS

There were 42 cases of complete uterine rupture in 144 474 deliveries, with an incidence rate of 0.029%. Twenty-seven cases had a scarred uterus and 15 had an unscarred uterus; Rupture of the lower uterine segment was predominant in the scarred uterus, whereas rupture of the body of the uterus was predominant in the non-scarred uterus (P ≤ 0.001). Newborns with Apgar score of 7 or less at 1 min in the non-scarred uterus group was more than that in the scarred uterus group (P = 0.001). There were no significant differences in the history of gynecologic surgery, induction of labor, mode of delivery, clinical features, maternal outcomes, neonatal weight, preterm birth rate, 5-min Apgar score, or neonatal mortality between the two groups (P > 0.05).

CONCLUSION

The clinical manifestations of uterine rupture are mainly abdominal pain, abnormal fetal heartbeat, or vaginal bleeding. Attention should also be paid to the history of previous uterine surgery. Strict prenatal management, early identification, and aggressive management can help improve maternal and child outcomes. Hysterectomy is not imperative.

Ultrasound evaluation of scar thickness for prediction of uterine dehiscence in term women with previous caesarean sections

Objective

To determine the role of ultrasound in evaluation of scar thickness for prediction of uterine dehiscence.

Method

This retrospective cross-sectional study was conducted in the Radiology department of Aga Khan University Hospital from 1st July to 31st December 2021 after approval from the University Ethic Committee. In this study pregnant women 18 to 40 years with a live singleton fetus with vertex presentation, at term, with history of prior caesarean section and availability of medical record were included. Using a curvilinear ultrasound transducer with optimally distended urinary bladder, the myometrial thickness was measured in the sagittal plane. The intraoperative visual findings of the lower uterine segment outcome at the time of C-section were recorded and categorized into two groups i.e., with and without dehiscence for statistical analysis.

Results

A total of 126 women were included. The mean age of the study participants was 29.8±4.1. The median gestational age was 35 (34-37) weeks. The highest AUC 0.58 was recorded for the scar thickness of ≤2.5mm with a sensitivity, specificity, PPV and NPV of 80.9%, 36.4%, 36.3% and 80.8% respectively. Similarly, the AUC for the scar thickness of ≤2mm was 0.55 with a sensitivity, specificity, PPV and NPV of 93%, 18.2%, 18.2% and 93% respectively.

Conclusion

Transabdominal Sonography is a safe technique to determine the LUS thickness during antenatal ultrasound at term. A cutoff value of ≤2mm showed a high sensitivity and negative predictive value of 93% for evaluating the risk of uterine dehiscence.

How the Mode of Delivery Is Influenced by Patient's Opinions and Risk-Informed Consent in Women with a History of Caesarean Section? Is Vaginal Delivery a Real Option after Caesarean Section?

Background/Objectives: In recent years, there has been a noticeable increase in the rates of caesarean section (CS), being one of the most commonly performed surgical procedures. For the following pregnancy, the previous CS represents the backbone of the risks and complications, such as uterine scar formation, uterine rupture, massive bleeding, and serious negative outcomes for both the mother and child. Our study followed patients with a history of CS from the birth planning prenatal check-up to delivery. Methods: We reviewed the records of 125 pregnant women with previous CS who presented in the third trimester for a prenatal check-up and completed our questionnaire from March 2021 to April 2022 in the Clinic of Obstetrics and Gynecology, Diakoneo Diak Klinikum Schwäbisch Hall, Germany. Results: Before the prenatal check-up, 74 patients (59.2%) preferred vaginal delivery (VD), while 51 (40.8%) preferred CS. After discussing birth planning with the obstetrician, 72 women (57.6%) decided upon VD, while 53 (42.4%) preferred CS. Ultimately, 78 (62.4%) of women gave birth through CS (either planned or by medical necessity) and 47 (37.6%) gave birth vaginally (either natural or per vacuum extraction). Conclusions: VD for patients with CS in their medical history is a real option. The patient must be well informed about the risks and benefits of the medical situation and should be empowered and supported on their chosen mode of delivery, which should be respected.

Duration time of labor progression for pregnant women of vaginal birth after cesarean in Hubei, China

OBJECTIVE

There have been limited reports on the duration of labor progression in pregnant women undergoing vaginal birth after cesarean (VBAC). This study aimed to investigate the duration of labor progression during VBAC in Hubei, China.

METHODS

A total of 359 pregnant women undergoing VBAC were enrolled as the VBAC group, meeting the following criteria: singleton pregnancy, gestational age ≥ 37 weeks, live birth, history of cesarean delivery, and a willingness to attempt a vaginal delivery. At the same time, 359 primiparas successfully undergoing vaginal delivery were randomly enrolled in the control group at a 1:1 ratio. Subsequently, the durations of the first, second, and third stages of labor were comparatively analyzed between the two groups.

RESULTS

The duration of the first, second, and total stages of labor in the VBAC group was significantly shorter than that in the control group (p < 0.05). There was no significant difference in the duration of the third stage of labor between the two groups (p > 0.05). The amount of blood loss, the rate of postpartum hemorrhage (PPH), and episiotomy were higher in the VBAC group than in the control group (p < 0.05). The rate of labor analgesia and intrapartum fever in the VBAC group was significantly lower than that in the control group (p < 0.05).

CONCLUSION

The duration of labor progression of the first, second, and total stages of VBAC is shorter than that in primiparous women in our observation in China.

The Feasibility of a Trial of Labor after Two Cesarean Deliveries: Outcomes and Prognostic Factors for Success

OBJECTIVE

This study aimed to determine whether a trial of labor after two cesarean deliveries (TOLAC2) increases the risk of adverse maternal and neonatal outcomes and identify prognostic factors for TOLAC2 success.

STUDY DESIGN

A retrospective cohort study was conducted at a single medical center. The study group was comprised of women with a history of TOLAC2. Outcomes were compared with women undergoing trial of labor after one previous cesarean delivery (TOLAC1). The primary outcome was trial of labor after cesarean delivery (TOLAC) success. Secondary outcomes included mode of delivery, uterine rupture, and combined adverse outcome (CAO; uterine rupture, postpartum hemorrhage, 5-minute Apgar score < 7, pH < 7.1). Logistic regression was used for the multivariate analysis to identify prognostic factors for TOLAC2 success.

RESULTS

A total of 381 women who underwent TOLAC2 were compared with 3,635 women who underwent TOLAC1. Women attempting TOLAC2 were less likely to achieve vaginal births after cesarean delivery (VBAC; 80.8 and 92.5%; odds ratio [OR]: 0.35; 95% confidence interval [CI]: 0.26-0.47; p < 0.001) and more likely to experience uterine rupture (0.8 vs. 0.2%; OR: 4.1; 95% CI: 1.1-15.9; p = 0.02) but not CAO (4.2 vs. 4.8%; OR: 0.88; 95% CI: 0.5-1.5; p = 0.3). TOLAC2 women with no previous vaginal deliveries had a lower chance of VBAC and a higher risk of uterine rupture compared with TOLAC1 women without a prior vaginal delivery (45.2 vs. 86.3%; OR: 0.13; 95% CI: 0.07-0.25; p < 0.001; 2.3 vs. 0%) and TOLAC2 women with a prior vaginal delivery (45.2 vs. 85.3%; OR: 0.14; 95% CI: 0.1-0.3; p < 0.0001; 2.4 vs. 0.6%; OR: 4.1; 95% CI: 0.4-46.3; p = 0.3). Multivariate analysis revealed that a history of vaginal delivery is an independent predictor of TOLAC2 success.

CONCLUSION

Women attempting TOLAC2 are less likely to achieve VBAC and are at greater risk of uterine rupture compared with those attempting TOLAC1. Despite these risks, the overall success rates remain very high, and the absolute risk of adverse outcomes is still very low. Prior vaginal delivery seems to have a protective effect on TOLAC outcomes. These data should be used to counsel women and assist in decision-making when considering the mode of delivery in women with two previous cesarean sections.

KEY POINTS

· TOLAC2 has a lower chance of success and higher rate of uterine rupture compared with TOLAC1.. · Previous vaginal delivery is an independent predictor of TOLAC2 success.. · Overall TOLAC2 outcomes are associated with high chances of success and low risk of uterine rupture..

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

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

Oxytocin augmentation and neurotransmitters in prolonged delivery: An experimental appraisal

The uterus is a highly innervated organ, and during labor, this innervation is at its highest level. Oxytocinergic fibers play an important role in labor and delivery and, in particular, the Lower Uterine Segment, cervix, and fundus are all controlled by motor neurofibers. Oxytocin is a neurohormone that acts on receptors located on the membrane of the smooth cells of the myometrium. During the stages of labor and delivery, its binding causes myofibers to contract, which enables the fundus of the uterus to act as a mediator. The aim of this study was to investigate the presence of oxytocinergic fibers in prolonged and non-prolonged dystocic delivery in a cohort of 90 patients, evaluated during the first and second stages of labor. Myometrial tissue samples were collected and evaluated by electron microscopy, in order to quantify differences in neurofibers concentrations between the investigated and control cohorts of patients. The authors of this experiment showed that the concentration of oxytocinergic fibers differs between non-prolonged and prolonged dystocic delivery. In particular, in prolonged dystocic delivery, compared to non-prolonged dystocic delivery, there is a lower amount of oxytocin fiber. The increase in oxytocin appeared to be ineffective in patients who experienced prolonged dystocic delivery, since the dystocic labor ended as a result of the altered presence of oxytocinergic fibers detected in this group of patients.

Evidence Based Management of Labor

Importance

Induction of labor (IOL) is a common obstetric intervention. Augmentation of labor and active management of the second stage is frequently required in obstetric practice. However, techniques around labor and induction management vary widely. Evidence-based practice regarding induction and labor management can reduce birth complications such as infection and hemorrhage and decrease rates of cesarean delivery.

Objective

To review existing evidence on IOL and labor management strategies with respect to preparing for induction, cervical ripening, induction and augmentation, and second stage of labor techniques.

Evidence acquisition

Review of recent original research, review articles, and guidelines on IOL using PubMed (2000-2022).

Results

Preinduction, pelvic floor training and perineal massage reduce postpartum urinary incontinence and perineal trauma, respectively. Timely membrane sweeping (38 weeks) can promote spontaneous labor and prevent postterm inductions. Outpatient Foley bulb placement in low-risk nulliparous patients with planned IOL reduces time to delivery. Inpatient Foley bulb use beyond 6 to 12 hours shows no benefit. When synthetic prostaglandins are indicated, vaginal misoprostol should be preferred. For nulliparous patients and those with obesity, oxytocin should be titrated using a high-dose protocol. Once cervical dilation is complete, pushing should begin immediately. Warm compresses and perineal massage decrease risk of perineal trauma.

Conclusion and relevance

Several strategies exist to assist in successful IOL and promote vaginal delivery. Evidence-based strategies should be used to improve outcomes and decrease risk of complications and cesarean delivery. Recommendations should be shared across interdisciplinary team members, creating a model that promotes safe patient care.

Induction of labor in twin pregnancy in patients with a previous cesarean delivery

BACKGROUND

Trial of labor after cesarean delivery (TOLAC) in twin gestations has been associated with decreased rates of successful vaginal delivery compared to singleton pregnancies, with mixed results regarding maternal and neonatal morbidity. However, induction of labor (IOL) in this unique population has not yet been fully evaluated.

OBJECTIVE

To assess success rates and maternal and neonatal outcomes in women with a twin gestation and a previous cesarean delivery undergoing IOL.

METHODS

A retrospective cohort study including women with a twin gestation and one previous cesarean delivery undergoing a trial of labor between the years 2009-2020. Patients requiring IOL were compared to those with a spontaneous onset of labor.

RESULTS

There were 53 patients who met the inclusion criteria: 31 had a spontaneous onset of labor (58%) and 22 required an IOL. Baseline characteristics were comparable between the groups apart from a history of labor arrest which was more common in the IOL group (40.9% vs. 9.6%, P = 0.006). A successful vaginal delivery occurred in all (100%) women with a spontaneous labor compared to 81% in the IOL group (p = 0.02). Secondary outcomes were comparable. A history of no previous vaginal delivery, maternal obesity, and IOL were associated with TOLAC failure.

CONCLUSIONS

IOL after cesarean delivery in twin gestation is associated with an increased risk of TOLAC failure compared to spontaneous onset of labor. However, no adverse neonatal or maternal outcomes were found. IOL in this high-risk population is feasible but patients should be counseled about the lower rate of success.

Predictors of vaginal delivery following balloon catheter for labor induction in women with one previous cesarean

BACKGROUND

The aim of this study was to estimate predictors for vaginal birth following balloon catheter induction of labor (IOL) in women with one previous cesarean section (CS) and an unfavorable cervix.

METHODS

This 4-year retrospective cohort study was conducted in Longhua District Central Hospital in Shenzhen China, between January 2015 and December 2018. Patients with one previous CS and a current singleton-term pregnancy who underwent balloon catheter cervical ripening and IOL were enrolled. Univariate analysis was used to identify predictive factors associated with vaginal birth after cesarean section (VBAC). Binary logistic regression was further used to identify which factors were independently associated with the outcome measure. The primary outcome was VBAC, which was a successful trial of labor after cesarean delivery (TOLAC) following IOL.

RESULTS

A total of 69.57% (208/299) of the women who planned for IOL had VBAC. In the final binary logistic regression equation, lower fetal weight (< 4000 g) (odds ratio [OR]5.26; 95% confidence interval [CI] 2.09,13.27), lower body mass index (BMI,<30 kg/m²) (OR 2.27; CI 1.21, 4.26), Bishop score after cervical ripening > 6 (OR 1.94; CI 1.37, 2.76) remained independently associated with an increased chance of VBAC.

CONCLUSIONS

The influencing factors of VBAC following IOL were fetal weight, BMI, and Bishop score after cervical ripening. Adequate individualized management and assessment of the IOL may help improve the VBAC rate.

Unexpected Uterine Rupture-A Case Report, Review of the Literature and Clinical Suggestions

BACKGROUND AND OBJECTIVES

Women with a history of cesarean section are a high-risk group because they are likely to develop uterine rupture during their next pregnancy. Current evidence suggests that a vaginal birth after cesarean section (VBAC) is associated with lower maternal mortality and morbidity than elective repeat cesarean delivery (ERCD). Additionally, research suggests that uterine rupture can occur in 0.47% of cases of trial of labor after cesarean section (TOLAC).

CASE DESCRIPTION

A healthy 32-year-old woman at 41 weeks of gestation, in her fourth pregnancy, was admitted to the hospital due to a dubious CTG record. Following this, the patient gave birth vaginally, underwent a cesarean section, and successfully underwent a VBAC. Due to her advanced gestational age and favorable cervix, the patient qualified for a trial of vaginal labor (TOL). During labor induction, she displayed a pathological CTG pattern and presented symptoms such as abdominal pain and heavy vaginal bleeding. Suspecting a violent uterine rupture, an emergency cesarean section was performed. The presumed diagnosis was confirmed during the procedure-a full-thickness rupture of the pregnant uterus was found. The fetus was delivered without signs of life and successfully resuscitated after 3 min. The newborn girl of weight 3150 g had an Apgar score of 0/6/8/8 at 1, 3, 5, and 10 min. The uterine wall rupture was closed with two layers of sutures. The patient was discharged 4 days after the cesarean section without significant complications, with a healthy newborn girl.

CONCLUSIONS

Uterine rupture is a rare but severe obstetric emergency and can be associated with maternal and neonatal fatal outcomes. The risk of uterine rupture during a TOLAC attempt should always be considered, even if it is a subsequent TOLAC.

Induction of Labor in Women with Previous Cesarean Section and Unfavorable Cervix: A Retrospective Cohort Study

Background: The efficacy and safety of a cervical ripening balloon (CRB) in women with a previous cesarean section (CS) and unfavorable Bishop score are still controversial. Methods: A retrospective cohort study was performed across six tertiary hospitals from 2015 to 2019. Women with one previous transverse CS, singleton cephalic term pregnancy and BS < 6 were included if submitted to labor induction with a CRB. The main outcome was the rate of vaginal birth after cesarean (VBAC) after CRB ripening. Secondary outcomes were abnormal composite fetal and maternal outcomes. Results: Of the 265 women included, 57.3% had successful vaginal birth. Augmentation improved vaginal delivery (32.2% vs. 21.2%). Intrapartum analgesia was associated with an increased VBAC rate (58.6% vs. 34.5%). Maternal BMI ≥30 and age ≥40 years increased emergency CS rate (11.8% vs. 28.3% and 7.2 vs. 15.9%). Composite adverse maternal outcome occurred in 4.8% of CRB group women and increased to 17.6% when associated with oxytocin. Uterine rupture occurred in one case (0.4%) in the CRB-oxytocin group. Poorer fetal outcome occurred after emergency CS, if compared to successful VBAC (12.4% vs. 3.3%). Conclusions: In women with a previous CS and unfavorable Bishop score, induction of labor with a CRB can be considered safe and effective.

Directive clinique no 432c : Déclenchement artificiel du travail

OBJECTIFS

Présenter des données probantes et des recommandations sur la maturation cervicale et le déclenchement artificiel du travail. Fournir de l'information aux professionnels accoucheurs et aux personnes enceintes sur les soins périnataux optimaux et la prévention des interventions obstétricales inutiles.

POPULATION CIBLE

Toutes les patientes enceintes. BéNéFICES, RISQUES ET COûTS: La mise en application interprofessionnelle et cohérente de la présente directive, l'équipement adéquat et le personnel compétent améliorent la sécurité des soins per partum. Les personnes enceintes et leurs personnes de soutien doivent être informées des risques et bénéfices du déclenchement artificiel du travail. DONNéES PROBANTES: La littérature publiée jusqu'en mars 2022 a été passée en revue. Une recherche a été effectuée dans les bases de données PubMed, CINAHL et Cochrane Library pour répertorier des revues systématiques, des essais cliniques randomisés et des études observationnelles sur la maturation cervicale et le déclenchement artificiel du travail. La littérature grise (non publiée) a été obtenue à l'aide de recherches menées dans des sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, des registres d'essais cliniques et des sites Web de sociétés de spécialité médicale nationales et internationales. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins obstétricaux. DÉCLARATIONS SOMMAIRESMISOPROSTOL: OCYTOCINE: RECOMMANDATIONS.

Guideline No. 432c: Induction of Labour

OBJECTIVES

This guideline presents evidence and recommendations for cervical ripening and induction of labour. It aims to provide information to birth attendants and pregnant individuals on optimal perinatal care while avoiding unnecessary obstetrical intervention.

TARGET POPULATION

All pregnant patients.

BENEFITS, RISKS, AND COSTS

Consistent interprofessional use of the guideline, appropriate equipment, and trained professional staff enhance safe intrapartum care. Pregnant individuals and their support person(s) should be informed of the benefits and risks of induction of labour.

EVIDENCE

Literature published to March 2022 was reviewed. PubMed, CINAHL, and the Cochrane Library were used to search for systematic reviews, randomized control trials, and observational studies on cervical ripening and induction labour. Grey (unpublished) literature was identified by searching the websites of health technology assessment and health technology related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

All providers of obstetrical care.

SUMMARY STATEMENTS

Misoprostol OXYTOCIN: RECOMMENDATIONS.

Artificial rupture of membranes as a mode for induction of labor in women with a previous cesarean section- a retrospective cohort study

BACKGROUND

Induction of labor in women with a previous cesarean section (CS) is associated with increased rates of uterine rupture and failed attempt for vaginal delivery. Prostaglandins use is contraindicated in this population, limiting available options for cervical ripening.

OBJECTIVE

To evaluate the efficacy and safety of artificial rupture of membranes (AROM) as a mode of Induction of labor (IOL) in women with a previous cesarean section.

METHODS

A retrospective cohort study conducted in a single tertiary care center between January 2015 and October 2020. Women with one previous cesarean section and a current singleton term pregnancy requiring IOL, with an unfavorable cervix, were included. The primary outcome was a successful vaginal delivery (VBAC); secondary outcomes were rates of chorioamnionitis, uterine rupture and low Apgar score (< 7).

RESULTS

Of the 665 women who met the inclusion criteria, 492 (74%) did not receive subsequent oxytocin and 173 (26%) did. There were significant differences in the baseline characteristics between these two groups, including maternal age, cervical dilation at presentation, parity, and a history of a previous VBAC. Among women who were induced solely by AROM the rate of a successful TOLAC was higher (81.3% vs 73.9%), total time of IOL was shorter (mean 8.7 h vs.16.1 h) and the risk of chorioamnionitis was lower (7.3% vs 18.4%). When subdividing the women who received oxytocin into early (< 12 h after AROM) vs late (> 12 h after AROM) administration, there were no significant changes in the rates of successful VBAC or of chorioamnionitis.

CONCLUSION

AROM as a single mode of IOL in women with a previous CS is a safe and efficient practice with high rates of successful VBAC. When spontaneous labor does not develop, there is no advantage to delay the administration of oxytocin.

Analysis of Maternal and Infant Outcomes and Related Factors of Vaginal Delivery of Second Pregnancy after Cesarean Section

Objective

To explore the clinical effect of different delivery methods and the safety of vaginal delivery of second pregnancy after cesarean section and analyze the related factors.

Methods

A total of 738 eligible pregnant women who underwent cesarean section from September 2018 to August 2020 were randomly selected from our hospital. Among them, 527 pregnant women successfully delivered vaginally were selected as the observation group, and 211 pregnant women who failed vaginal delivery were selected as the control group. To analyze the factors that influence the success of vaginal delivery of second pregnancy after cesarean section and compare the outcomes of mother and infant in two groups.

Results

There was no significant difference in age, prenatal body mass index (BMI), and thickness of lower uterine segment between the two groups (P > 0.05). There were significant differences in fetal head orientation, fetal abdominal circumference, fetal biparietal diameter, uterine height, premature rupture of membranes, Bishop score, and epidural anesthesia during labor between the two groups (P < 0.05). Multivariate logistic regression analysis showed that fetal abdominal circumference, fetal head orientation, Bishop score, and epidural anesthesia during labor were independent factors affecting the success of VBAC (P < 0.05). There was no significant difference in the incidence of uterine rupture between the two groups (P > 0.05). The amount of postpartum hemorrhage in the observation group was significantly lower than that in the control group (P < 0.05). There was no significant difference in Apgar score, asphyxia rate, and hospitalization rate between the two groups (P > 0.05). There was no significant difference in the incidence of complications between the two groups (P > 0.05).

Conclusion

There are many factors that influence the success of vaginal delivery after cesarean section. Through prenatal comprehensive evaluation of vaginal delivery conditions, we can guide the parturient to choose a reasonable mode of delivery, reduce the incidence of complications, and improve the outcome of mother and baby.

Spontaneous Rupture of Unscarred Uterus in a Term Primagravida with Lethal Skeletal Dysplasia Fetus (Thanatophoric dysplasia). A Case Report and Review of the Literature

Background and Importance

 Spontaneous uterine rupture, especially in an unscarred uterus, is a rare pregnancy complication that can cause severe morbidity and mortality in both the mother and the fetus. The vast majority of uterine ruptures occur in the presence of a previous uterine scar, most commonly from a previous cesarean delivery. To our knowledge, here we reported the first case of spontaneous rupture of unscarred uterus in a term primigravida secondary to lethal skeletal dysplasia fetus (Type 1 Thanatophoric dysplasia) faced by a practicing clinician in an underdeveloped country (Somalia) with a successful outcome.

Case Presentation

 The patient was 24 yrs. Old Primagravida, at 40 weeks gestation by LMP, presented with abdominal pain and active vaginal bleeding; she did not receive antenatal care during pregnancy; after initial abdominal ultrasonography and vaginal examination, laparotomy was performed due to high suspicion of uterine rupture. After dead fresh fetal extraction, the uterine defect was repaired successfully, and the patient was discharged home in good condition after several days.

Conclusion

 Through this case, we would like to highlight the urgent need to focus on and recognize the importance of receiving antenatal care in the community so that the burden of thousands of lives lost each year can be reduced.

Trial of labor after cesarean section

Fourth, before shared decision making with pregnant women, the exact benefits and risks of both TOLAC and ERCD should be fully and thorough in discussion. A speedy recovery, the enjoying self-control natural birth, immediately entering into a bonding with their newborns and breastfeeding faster of mothers and avoidance of C/S related morbidity, such as intrauterine adhesion, pelvic adhesion, the risk of subsequent pregnancy (placenta accreta spectrum), and postpartum hemorrhage are reported to encourage women favor the TOLAC; and by contrast, for ERCD, the possible advantages include easily controlling labor pain, avoidance of vaginal or pelvic floor damage with subsequent development of sequela, such as stress urinary incontinence, lower genito-urinary tract dysfunction, pelvic organ prolapse etc., and the ease of a scheduled birth and following postpartum care [5,6,9,19-21].

Cohort Study Summary of the Effects of Carboprost Tromethamine Combined with Oxytocin on Infant Outcome, Postpartum Hemorrhage and Uterine Involution of Parturients Undergoing Cesarean Section

Background

Carboprost tromethamine injection has a high safety factor in clinical application and has a good effect on uterine smooth muscle and vasoconstriction. Carboprost aminobutyriol combined with oxytocin may be beneficial to infant outcome and uterine involution after cesarean section.

Objective

To investigate the effects of carboprost tromethamine combined with oxytocin on infant outcome, postpartum hemorrhage, and uterine involution in parturients undergoing cesarean section.

Methods

A total of 120 parturients undergone cesarean section in our hospital from February 2019 to April 2021 were selected as the object of study. The parturients were randomly divided into control group (n = 60) and research group (n = 60). The control group was treated with oxytocin, and the research group was treated with carboprost aminobutyriol combined with oxytocin. The amount of maternal bleeding, uterine floor decline index, the end of lochia, poor rate of uterine involution, infant outcome, and the incidence of adverse drug reactions were compared between the two groups.

Results

The amount of bleeding in the research group was significantly lower than that in the control group (P < 0.05). The position of the last uterine floor and the index of uterine floor downward movement in the research group were significantly higher than those in the control group (P < 0.05). The disappearance time of bloody lochia and serous lochia in the research group was significantly shorter than that in the control group (P < 0.05). The end time of lochia in the research group was higher than that in the control group, and the rate of uterine involution in the research group was lower than that in the control group (P < 0.05). The neonatal weight and Apgar score in the research group were higher than those in the control group, and the hospitalization rate of neonatal ICU in the research group was significantly lower than that in the control group. The incidence of adverse reactions in the research group was significantly lower than that in the control group (P < 0.05).

Conclusion

Carboprost aminobutyriol combined with carbestatin can effectively prevent the occurrence of bleeding after cesarean section, improve uterine involution, and improve neonatal birth quality, which is worth popularizing.

Use and Effects of Augmentation of Labor with Oxytocin: A Single-Center, Retrospective, Case-Control Study of 4350 Women in Warsaw, Poland, 2015-2020

BACKGROUND Although there have been some recent clinical trials on the effects of augmentation of labor with oxytocin, or augmentation of labor, there are no clinical guidelines to explain the variations in obstetric practice between countries and within countries. This retrospective case-control study from a single center in Warsaw, Poland aimed to evaluate the use and effects of augmentation of labor with oxytocin in 4350 women between 2015 and 2020. MATERIAL AND METHODS This was a single-center, retrospective, case-control study in which 29 455 cases were qualified for analysis. The study included the analysis of 2 groups: the study group consisted of 4382 patients who underwent stimulation of childbirth, and the control group consisted of 25 073 patients who did not undergo this obstetric procedure. RESULTS Multivariate logistic regression analysis showed that the factors increasing the frequency of augmentation of labor were higher BMI (P<0.05), preinduction (P<0.05), epidural anesthesia (P<0.05), and family present at birth (P<0.05). Factors influencing reduction in the frequency of augmentation of labor were higher number of deliveries (P<0.05), vaginal birth after cesarean (P<0.05), and pre-pregnancy hypertension (P<0.05). CONCLUSIONS This study from a single center in Poland showed that BMI, preinduction, epidural anesthesia, and family present at birth significantly increased the frequency of labor stimulation with oxytocin. However, a history of previous pregnancies, previous cesarean sections, and pre-pregnancy hypertension significantly reduced the frequency of augmentation of labor with oxytocin.

Vaginal birth after cesarean section: Experience from a regional hospital

OBJECTIVE

Trial of labor after cesarean section (TOLAC) is an option for women with previous cesarean section. However, few women choose this option because of safety concerns. We evaluate the safety and risks associated with TOLAC and the success rate of vaginal birth after cesarean delivery (VBAC).

MATERIAL AND METHODS

We reviewed all patients with a history of previous cesarean section that underwent elective repeat cesarean section (ERCS) or TOLAC in a regional teaching hospital from Nov, 2013 to May, 2018. Maternal basic clinical information, intrapartum management, postpartum complications, and neonatal outcomes were analyzed.

RESULTS

199 pregnant women with a history of at least one previous cesarean section were enrolled. 156 women received ERCS and 43 women (21.6%) underwent TOLAC, with 37 (86.0%) who underwent successful VBAC. The VBAC rate was 18.6%. Higher success rate was found in women with previous vaginal birth than in women without vaginal birth (100% vs. 81.8%). One case (2.3%) in the VBAC group was complicated with uterine rupture and inevitable neonatal death during second stage of labor. The uterus was repaired without maternal complications. In another case, the newborn's condition was complicated with low APGAR score (<7) at birth due to maternal chorioamnionitis. Among indications for previous cesarean section, cephalo-pelvic disproportion (CPD) was associated with TOLAC failure and uterine rupture after VBAC.

CONCLUSION

VBAC is a feasible and safe option. Modes of delivery should be thoroughly discussed when considering TOLAC for women with history of previous cesarean section due to CPD, considering its association with TOLAC failure in second stage of labor.

Transabdominal versus transvaginal ultrasound to assess the thickness of lower uterine segment at term in women with previous cesarean section

OBJECTIVE

This study aims to compare transvaginal (TVS) and transabdominal (TAS) ultrasonography precision in to evaluate the lower uterine (LUS) thickness in women with a previous Cesarean section at the term pregnancy; to be an effective method for assessment of previous cesarean scar strength.

MATERIAL AND METHODS

An observational cross-sectional study was conducted at kasr el-ainy Hospital in Egypt. From May to November 2020, we admitted 130 pregnant women at term with a previous cesarean section for an elective cesarean delivery. Lower uterine segment thickness was obtained using both transvaginal ultrasound and transabdominal ultrasound before the cesarean. The exact thickness of the lower uterine segment was recorded using a sterile metal ruler before the neonate had been delivered.

RESULTS

The mean thickness of the lower uterine segment obtained by transabdominal ultrasound was 5.2 ± 1.6 mm and 4.8 ± 1.33 mm by transvaginal ultrasound, then compared each of them to the mean actual thickness, which was 4.5 ± 1.22 mm. The lower uterine segment thickness with transabdominal ultrasound showed a good correlation (r = 0.722) with the actual thickness, the correlation with transvaginal ultrasound was better (r = 0.944). A cut-off value transvaginal ultrasound of 3.65 mm with 90.8% sensitivity and 65.6% specificity.

CONCLUSION

Transvaginal ultrasound is more accurate in assessing the thickness of the lower uterine segment than transabdominal ultrasound. A total lower uterine segment thickness of <3.65 is considered a thin scar, and <2.85 mm is associated with a higher risk of uterine dehiscence. The trial was registered in ClinicalTrials.gov registry with clinical trial. https://clinicaltrials.gov/ct2/show/NCT04687891.

Mechanical Methods for the Induction of Labour After Previous Caesarean Section – An Updated, Evidence-based Review

There are currently no up-to-date evidence-based recommendations on the preferred method to induce labour after previous Caesarean section, especially for patients with unripe cervix, as randomised controlled studies are lacking. Intravenous oxytocin and misoprostol are contraindicated in these women because of the high risk of uterine rupture. In women with ripe cervix (Bishop Score > 6), intravenous administration of oxytocin is an effective procedure with comparable rates of uterine rupture to those with spontaneous onset of labour. Vaginal prostaglandin E ₂ (PGE ₂ ) and mechanical methods (balloon catheters, hygroscopic cervical dilators) are effective methods to induce labour in pregnant women with unripe cervix and previous Caesarean section. According to current guidelines, the administration of PGE ₂ is associated with a higher rate of uterine rupture compared to balloon catheters. Balloon catheters are therefore a suitable alternative to PGE ₂ to induce labour after previous Caesarean section, even though this is an off-label use. In addition to two meta-analyses published in 2016, 12 mostly retrospective cohort/observational studies with low to moderate levels of evidence have been published on mechanical methods of cervical ripening after previous Caesarean section. But because of the significant heterogeneity of the studies, substantial differences in study design, and insufficient numbers of pregnant women included in the studies, it is not possible to make any evidence-based recommendations based on these studies. According to a recent meta-analysis, the average rate using balloon catheters is approximately 53% and the average rate after spontaneous onset of labour is 72%. The uterine rupture rate was 0.2–0.9% for vaginal PGE ₂ and 0.56–0.94% for balloon catheters and is therefore comparable to the uterine rupture rate associated with spontaneous onset of labour. According to the product informations, hygroscopic cervical dilators (Dilapan-S) are currently the only method which is not contraindicated for cervical ripening/induction of labour in women with previous Caesarean section, although data are insufficient. Well-designed, randomised, controlled studies with sufficient case numbers comparing balloon catheters and hygroscopic cervical dilators with mechanical methods and vaginal prostaglandin E ₂ /oral misoprostol are therefore necessary to allow proper decision-making.

Risk factors and outcomes associated with type of uterine rupture

PURPOSE

To identify risk factors associated with the occurrence of complete uterine rupture (CUR) in comparison to partial uterine rupture (PUR) to further investigate to what extent a standardized definition is needed and what clinical implications can be drawn.

METHODS

Between 2005 and 2017 cases with CUR and PUR at Charité University Berlin, Germany were retrospectively identified. Demographic, obstetric and outcome variables were analyzed regarding the type of rupture. Binary multivariate regression analysis was conducted to identify risk factors associated with CUR. In addition, the intended route of delivery (trial of labor after cesarean delivery (TOLAC) and elective repeat cesarean delivery (ERCD)), divided according to the type of rupture, was compared.

RESULTS

92 cases with uterine rupture were identified out of a total of 64.063 births (0.14%). Puerperal complications were more frequent in CUR (67.9 versus 41.1%, p = 0.021). Multiparity ≥ 3 was more frequent in CUR (31 versus 10.7%, p = 0.020). Factors increasing the risk for CUR were parity ≥ 3 (OR = 3.8, p = 0.025), previous vaginal birth (OR = 4.4, p = 0.011), TOLAC (OR = 6.5, p < 0.001) and the use of oxytocin (OR = 2.9, p = 0.036). After multivariate analysis, the only independent risk factor associated with CUR was TOLAC (OR = 7.4, p = 0.017).

CONCLUSION

TOLAC is the only independent risk factor for CUR. After optimized antenatal counselling TOLAC and ERCD had comparable short-term maternal and fetal outcomes in a high resource setting. A high number of previous vaginal births does not eliminate the risk of uterine rupture. A clear distinction between CUR and PUR is essential to ensure comparability among studies.

Induction of labour in patients with prior caesarean births or uterine surgery

The current evidence favours trial of labour after one caesarean in the absence of any other contraindications, recognizing that risks with both trial of labour after caesarean (TOLAC) and elective repeat caesarean section (ERCS) birth are relatively uncommon. When the need for induction of labour (IOL) following a previous caesarean arises, shared decision-making should be based on the current available evidence. This approach, however, needs to be tailored, taking into account the individual's history, initial examination and response to the ongoing process of induction to optimize the maternal and foetal outcomes. This paper aims to review the evidence and provide guidance on decision making surrounding labour induction in a pregnancy following a prior caesarean or uterine surgery.

Cervical ripening after cesarean section: a prospective dual center study comparing a mechanical osmotic dilator vs. prostaglandin E2

OBJECTIVES

Worldwide, the overall cesarean section is rising. Trial of labor after cesarean (TOLAC) is an overall safe option with an immediate impact on neonatal and maternal short- and long-term health. Since the use of prostaglandins in cervical ripening is associated with an increased risk of uterine rupture, mechanical methods as balloon catheters or osmotic dilators have been suggested for cervical ripening prior to induction of labour. Here we are analyzing and comparing the VBAC rate, as well as maternal and fetal outcome in cervical ripening prior to TOLAC.

METHODS

This prospective dual center study analyses maternal and neonatal outcomes of TOLAC in women with an unfavorable cervix requiring cervical ripening agent. The prospective application of an osmotic dilator (Dilapan-S, n=104) was analysed in comparison to the retrospective application of off-label dinoprostone (n=102).

RESULTS

The overall fetal and neonatal outcome revealed no significant differences in both groups. Patients receiving cervical ripening with the osmotic dilator delivered vaginally/by ventouse in 52% of cases, compared to 53% when using dinoprostone (p=0.603). The interval between application to onset of labor was significantly higher in the osmotic dilator group (37.9 vs.20.7 h, p=<0.001). However, time from onset of labor to delivery was similar in both groups (7.93 vs. 7.44 h, p=0.758). There was one case of uterine rupture in the dinoprostone group.

CONCLUSIONS

Our data shows that the application of the osmotic dilator leads to similar outcomes in VBAC rate and time from onset of labor to delivery as well as safety in both groups compared to off-label use dinoprostone. Cervical ripening using the mechanical dilator is a viable and effective option, without the risk of uterine hyperstimulation.