Attempted operative vaginal delivery vs repeat cesarean in the second stage among women undergoing a trial of labor after cesarean delivery

Assisted vaginal birth in 21st century: current practice and new innovations

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39-0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32-2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world.

Correlation Between Previous Caesarean Section and Adverse Maternal Outcomes Accordingly With Robson Classification: Systematic Review and Meta-Analysis

Background: The increasing rates of Caesarean section (CS) beyond the WHO standards (10–15%) pose a significant global health concern.

Objective: Systematic review and meta-analysis to identify an association between CS history and maternal adverse outcomes for the subsequent pregnancy and delivery among women classified in Robson classification (RC).

Search Strategy: PubMed/Medline, EbscoHost, ProQuest, Embase, Web of Science, BIOSIS, MEDLINE, and Russian Science Citation Index databases were searched from 2008 to 2018.

Selection Criteria: Based on Robson classification, studies reporting one or more of the 14 adverse maternal outcomes were considered eligible for this review.

Data Collection: Study design data, interventions used, CS history, and adverse maternal outcomes were extracted.

Main Results: From 4,084 studies, 28 (n = 1,524,695 women) met the inclusion criteria. RC group 5 showed the highest proportion among deliveries followed by RC10, RC7, and RC8 (67.71, 32.27, 0.02, and 0.001%). Among adverse maternal outcomes, hysterectomy had the highest association after preterm delivery OR = 3.39 (95% CI 1.56–7.36), followed by Severe Maternal Outcomes OR = 2.95 (95% CI 1.00–8.67). We identified over one and a half million pregnant women, of whom the majority were found to belong to RC group 5.

Conclusions: Previous CS was observed to be associated with adverse maternal outcomes for the subsequent pregnancies. CS rates need to be monitored given the prospective risks which may occur for maternal and child health in subsequent births.

Evaluation of factors that predict the success rate of trial of labor after the cesarean section

Background

For most women who have had a previous cesarean section, vaginal birth after cesarean section (VBAC) is a reasonable and safe choice, but which will increase the risk of adverse outcomes such as uterine rupture. In order to reduce the risk, we evaluated the factors that may affect VBAC and and established a model for predicting the success rate of trial of the labor after cesarean section (TOLAC).

Methods

All patients who gave birth at Northwest Women’s and Children’s Hospital from January 2016 to December 2018, had a history of cesarean section and voluntarily chose the TOLAC were recruited. Among them, 80% of the population was randomly assigned to the training set, while the remaining 20% were assigned to the external validation set. In the training set, univariate and multivariate logistic regression models were used to identify indicators related to successful TOLAC. A nomogram was constructed based on the results of multiple logistic regression analysis, and the selected variables included in the nomogram were used to predict the probability of successfully obtaining TOLAC. The area under the receiver operating characteristic curve was used to judge the predictive ability of the model.

Results

A total of 778 pregnant women were included in this study. Among them, 595 (76.48%) successfully underwent TOLAC, whereas 183 (23.52%) failed and switched to cesarean section. In multi-factor logistic regression, parity = 1, pre-pregnancy BMI < 24 kg/m², cervical score ≥ 5, a history of previous vaginal delivery and neonatal birthweight < 3300 g were associated with the success of TOLAC. The area under the receiver operating characteristic curve in the prediction and validation models was 0.815 (95% CI: 0.762–0.854) and 0.730 (95% CI: 0.652–0.808), respectively, indicating that the nomogram prediction model had medium discriminative power.

Conclusion

The TOLAC was useful to reducing the cesarean section rate. Being primiparous, not overweight or obese, having a cervical score ≥ 5, a history of previous vaginal delivery or neonatal birthweight < 3300 g were protective indicators. In this study, the validated model had an approving predictive ability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04004-z.

Perinatal outcome after vacuum assisted delivery with digital feedback on traction force; a randomised controlled study

Background

Low and mid station vacuum assisted deliveries (VAD) are delicate manual procedures that entail a high degree of subjectivity from the operator and are associated with adverse neonatal outcome. Little has been done to improve the procedure, including the technical development, traction force and the possibility of objective documentation. We aimed to explore if a digital handle with instant haptic feedback on traction force would reduce the neonatal risk during low or mid station VAD.

Methods

A two centre, randomised superiority trial at Karolinska University Hospital, Sweden, 2016–2018. Cases were randomised bedside to either a conventional or a digital handle attached to a Bird metal cup (50 mm, 80 kPa). The digital handle measured applied force including an instant notification by vibration when high levels of traction force were predicted according to a predefined algorithm. Primary outcome was a composite of hypoxic ischaemic encephalopathy, intracranial haemorrhage, seizures, death and/or subgaleal hematoma. Three hundred eighty low and mid VAD in each group were estimated to decrease primary outcome from six to 2 %.

Results

After 2 years, an interim analyse was undertaken. Meeting the inclusion criteria, 567 vacuum extractions were randomized to the use of a digital handle (n = 296) or a conventional handle (n = 271). Primary outcome did not differ between the two groups: (2.7% digital handle vs 2.6% conventional handle). The incidence of primary outcome differed significantly between the two delivery wards (4% vs 0.9%, p < 0.05). A recalculation of power revealed that 800 cases would be needed in each group to show a decrease in primary outcome from three to 1 %. This was not feasible, and the study therefore closed.

Conclusions

The incidence of primary outcome was lower than estimated and the study was underpowered. However, the difference between the two delivery wards might reflect varying degree of experience of the technical equipment. An objective documentation of the extraction procedure is an attractive alternative in respect to safety and clinical training. To demonstrate improved safety, a multicentre study is required to reach an adequate cohort. This was beyond the scope of the study.

Trial registration

ClinicalTrials.gov NCT03071783, March 1, 2017, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03604-z.

Prediction of vaginal birth after cesarean deliveries using machine learning

BACKGROUND

Efforts to reduce cesarean delivery rates to 12-15% have been undertaken worldwide. Special focus has been directed towards parturients who undergo a trial of labor after cesarean delivery to reduce the burden of repeated cesarean deliveries. Complication rates are lowest when a vaginal birth is achieved and highest when an unplanned cesarean delivery is performed, which emphasizes the need to assess, in advance, the likelihood of a successful vaginal birth after cesarean delivery. Vaginal birth after cesarean delivery calculators have been developed in different populations; however, some limitations to their implementation into clinical practice have been described. Machine-learning methods enable investigation of large-scale datasets with input combinations that traditional statistical analysis tools have difficulty processing.

OBJECTIVE

The aim of this study was to evaluate the feasibility of using machine-learning methods to predict a successful vaginal birth after cesarean delivery.

STUDY DESIGN

The electronic medical records of singleton, term labors during a 12-year period in a tertiary referral center were analyzed. With the use of gradient boosting, models that incorporated multiple maternal and fetal features were created to predict successful vaginal birth in parturients who undergo a trial of labor after cesarean delivery. One model was created to provide a personalized risk score for vaginal birth after cesarean delivery with the use of features that are available as early as the first antenatal visit; a second model was created that reassesses this score after features are added that are available only in proximity to delivery.

RESULTS

A cohort of 9888 parturients with 1 previous cesarean delivery was identified, of which 75.6% of parturients (n=7473) attempted a trial of labor, with a success rate of 88%. A machine-learning-based model to predict when vaginal delivery would be successful was developed. When features that are available at the first antenatal visit are used, the model showed a receiver operating characteristic curve with area under the curve of 0.745 (95% confidence interval, 0.728-0.762) that increased to 0.793 (95% confidence interval, 0.778-0.808) when features that are available in proximity to the delivery process were added. Additionally, for the later model, a risk stratification tool was built to allocate parturients into low-, medium-, and high-risk groups for failed trial of labor after cesarean delivery. The low- and medium-risk groups (42.4% and 25.6% of parturients, respectively) showed a success rate of 97.3% and 90.9%, respectively. The high-risk group (32.1%) had a vaginal delivery success rate of 73.3%. Application of the model to a cohort of parturients who elected a repeat cesarean delivery (n=2145) demonstrated that 31% of these parturients would have been allocated to the low- and medium-risk groups had a trial of labor been attempted.

CONCLUSION

Trial of labor after cesarean delivery is safe for most parturients. Success rates are high, even in a population with high rates of trial of labor after cesarean delivery. Application of a machine-learning algorithm to assign a personalized risk score for a successful vaginal birth after cesarean delivery may help in decision-making and contribute to a reduction in cesarean delivery rates. Parturient allocation to risk groups may help delivery process management.

Still No Substantial Evidence to Use Prophylactic Antibiotic at Operative Vaginal Delivery: Systematic Review and Meta-Analysis

Background

Postpartum maternal infection is still a common problem worldwide, mainly due to obstetric risk factors. The use of prophylactic antibiotic at operative vaginal delivery (OVD), taking it as a standalone risk factor, has been controversial. The purpose of this review was to rigorously evaluate the association of OVD with postpartum infection and shed light on such highly controversial issue.

Methods

A computer-based literature search was done mainly in the databases of PUBMED, HINARI health research, and the Cochrane library. Systematic review and meta-analysis were done by including 14 articles published between 1990 and August 2019.

Results

The average absolute risk of postpartum infection at OVD from seven large cohort studies was 1%. Few studies showed a weak association of OVD with postpartum infection without being adjusted to perineal wound, but the pooled meta-analysis showed statistically significant association with non-OVD. In the included randomized trial, 97% of the study participants had perineal wound for whom repairs were performed; the risks of maternal infection and perineal wound breakdown were comparable, and maternal infections other than perineal wound infection did not show significant difference between prophylactic antibiotic and placebo groups. The majority of included studies demonstrated a strong association of postpartum infection and perineal wound dehiscence with episiotomy and perineal tear.

Conclusion

Both the relative and absolute risks of postpartum infection at OVD are extremely low unless accompanied by episiotomy and 3^rd/4^tht degree perineal tear. From previous studies, there is no substantial evidence to use prophylactic antibiotic at OVD, but episiotomy and perineal tear.

Operative Vaginal Delivery Is a Safe Option in Women Undergoing a Trial of Labor after Cesarean

Objective  To compare outcomes of operative intervention in the second stage of labor during trial of labor after cesarean (TOLAC). Study Design  A secondary analysis of the Maternal-Fetal Medicine Units Network cesarean section registry was conducted. Analysis was by first attempted mode of delivery. Results  A total of 1,837 met inclusion criteria. Subjects in the operative vaginal groups (OVDs) were more likely to have a prior vaginal delivery (vacuum 34.2%; forceps 34.3%) than the repeat cesarean delivery (RCD) group (22.6%; p  < 0.0001). Most OVD attempts were successful (forceps 90.4%; vacuum 92.6%). Neonatal morbidity was not different (12.1% forceps vs. 14.6% vacuum; 14.8% RCD). Maternal morbidity was highest among forceps deliveries (32.3 vs. 24.3% vacuum; 22.0% RCD, p  = 0.0001). RCD was associated with surgical injury (2.7 vs. 0.7% forceps; 0% vacuum; p  < 0.0001), endometritis (8.4 vs. 3.2% forceps, 1.2% vacuum; p  < 0.0001), and wound complications (1.9 vs. 0.4% forceps; 0.3% vacuum; p  = 0.006). OVD was associated with anal sphincter laceration (22.7% forceps, 15.5% vacuum; 0% RCD; p  = 0.01). Conclusion  The success rate of OVD is high in TOLAC with similar outcomes to RCD. Maternal composite outcomes were highest with forceps-assisted vaginal deliveries. However, considering overall morbidity, OVD in the second stage of labor in TOLAC is a reasonable, safe option in selected cases.

Operative vaginal delivery and post-partum infection

During the past decade, there has been an increase in the awareness of infections associated with pregnancy and delivery. The most significant cause of post-partum infection is caesarean section; 20-25% of operations are followed by wound infections, endometritis or urinary tract infections. Approximately 13% of women in the UK undergo operative vaginal delivery (OVD) with forceps or vacuum, which is also associated with an increased risk of infection, estimated at 0.7%-16% of these deliveries. Despite this, previous reviews have identified only one small trial of antibiotic prophylaxis in 393 women and concluded that there was insufficient evidence to support the routine use of prophylactic antibiotics after OVD. The ANODE trial, a multicentre, blinded, placebo-controlled trial from the UK, is due to report findings from more than 3400 women in 2019 and will be the largest study to date of antibiotic prophylaxis following OVD.

Outcome of vaginal birth after cesarean section: A retrospective comparative analysis of spontaneous versus induced labor in women with one previous cesarean section

Objective

The purpose of this study is to compare the success rate of vaginal birth after cesarean (VBAC) in spontaneous and induced labor.

Design

This is an 8-year retrospective comparative study.

Setting

University hospital.

Population

Five hundred and ninety-four women who had one previous lower segment cesarean delivery.

Materials and Methods

This is a retrospective study of all women, who had lower segment cesarean section, admitted for trial of labor between April 2010 and November 2016. Five hundred and sixty-seven women who elected to have trial of labor after one previous cesarean were included in the study, of these 477 (84.13%) had spontaneous onset of labor (control group) and 90 (15.87%) had induction of labor (IOL) (study group). Two hundred and seventy-seven women had no previous vaginal delivery, and 297 had one previous vaginal delivery.

Results

We compared the success rates of VBAC in women who had IOL with those who came with spontaneous labor. The rate of vaginal delivery after CS (VBAC) was 50.0% and 66.6% in the study and control groups, respectively. There was a significant increase in the rate of cesarean delivery due to fetal distress in the study group (P = 0.016). There were no cases of uterine rupture in the control group and one case in the study group. Patients who had spontaneous labor and at least one previous vaginal delivery have higher success rate of vaginal delivery.

Conclusion

Women with one previous CS, who undergo IOL, have lower success rates of vaginal delivery compared with those who presented in spontaneous labor. They also have higher risk of CS delivery due to fetal distress. Previous normal vaginal delivery increases the success rate of VBAC.

Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin

BACKGROUND

Trial of labor after cesarean (TOLAC) is a viable option for safe delivery. In some cases cervical ripening and subsequent labor induction is necessary. However, the commonly used prostaglandins are not licensed in this subgroup of patients and are associated with an increased risk of uterine rupture.

METHODS

This cohort study compares maternal and neonatal outcomes of TOLAC in women (n=82) requiring cervical ripening agents (osmotic dilator vs. prostaglandins). The initial Bishop scores (BSs) were 2 (0-5) and 3 (0-5) (osmotic dilator and prostaglandin group, respectively). In this retrospective analysis, Fisher's exact test, the Kruskal-Wallis rank sum test and Pearson's chi-squared test were utilized.

RESULTS

Vaginal birth rate (including operative delivery) was 55% (18/33) in the osmotic dilator group vs. 51% (25/49) in the dinoprostone group (P 0.886). Between 97% and 92% (32/33 and 45/49) (100%, 100%) of neonates had an Apgar score of >8 after 1 min (5, 10 min, respectively). The time between administration of the agent and onset of labor was 36 and 17.1 h (mean, Dilapan-S® group, dinoprostone group, respectively). Time from onset of labor to delivery was similar in both groups with 4.4 and 4.9 h (mean, Dilapan-S® group, dinoprostone group, respectively). Patients receiving cervical ripening with Dilapan-S® required oxytocin in 97% (32/33) of cases. Some patients presented with spontaneous onset of labor, mostly in the dinoprostone group (24/49, 49%). Amniotomy was performed in 64% and 49% (21/33 and 24/49) of cases (Dilapan-S® group and dinoprostone group, respectively).

CONCLUSIONS

This pilot study examines the application of an osmotic dilator for cervical ripening to promote vaginal delivery in women who previously delivered via cesarean section. In our experience, the osmotic dilator gives obstetricians a chance to perform induction of labor in these women.

The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations

Fetal malpositions and cephalic malpresentations are well-recognized causes of failure to progress in labor. They frequently require operative delivery, and are associated with an increased probability of fetal and maternal complications. Traditional obstetrics emphasizes the role of digital examinations, but recent studies demonstrated that this approach is inaccurate and intrapartum ultrasound is far more precise. The objective of this review is to summarize the current body of literature and provide recommendations to identify malpositions and cephalic malpresentations with ultrasound. We propose a systematic approach consisting of a combination of transabdominal and transperineal scans and describe the findings that allow an accurate diagnosis of normal and abnormal position, flexion, and synclitism of the fetal head. The management of malpositions and cephalic malpresentation is currently a matter of debate, and individualized depending on the general clinical picture and expertise of the provider. Intrapartum sonography allows a precise diagnosis and therefore offers the best opportunity to design prospective studies with the aim of establishing evidence-based treatment. The article is accompanied by a video that demonstrates the sonographic technique and findings.