Prediction of Success in External Cephalic Version for Breech Presentation at Term

Prediction Models for Successful External Cephalic Version: An Updated Systematic Review

OBJECTIVE

 To review the decision aids currently available or being developed to predict a patient's odds that their external cephalic version (ECV) will be successful.

STUDY DESIGN

 We searched PubMed/MEDLINE, Cochrane Central, and ClinicalTrials.gov from 2015 to 2022. Articles from a pre-2015 systematic review were also included. We selected English-language articles describing or evaluating models (prediction rules) designed to predict an outcome of ECV for an individual patient. Acceptable model outcomes included cephalic presentation after the ECV attempt and whether the ECV ultimately resulted in a vaginal delivery. Two authors independently performed article selection following PRISMA 2020 guidelines. Since 2015, 380 unique records underwent title and abstract screening, and 49 reports underwent full-text review. Ultimately, 17 new articles and 8 from the prior review were included. Of the 25 articles, 22 proposed one to two models each for a total of 25 models, while the remaining 3 articles validated prior models without proposing new ones.

RESULTS

 Of the 17 new articles, 10 were low, 6 moderate, and 1 high risk of bias. Almost all articles were from Europe (11/25) or Asia (10/25); only one study in the last 20 years was from the United States. The models found had diverse presentations including score charts, decision trees (flowcharts), and equations. The majority (13/25) had no form of validation and only 5/25 reached external validation. Only the Newman-Peacock model (United States, 1993) was repeatedly externally validated (Pakistan, 2012 and Portugal, 2018). Most models (14/25) were published in the last 5 years. In general, newer models were designed more robustly, used larger sample sizes, and were more mathematically rigorous. Thus, although they await further validation, there is great potential for these models to be more predictive than the Newman-Peacock model.

CONCLUSION

 Only the Newman-Peacock model is ready for regular clinical use. Many newer models are promising but require further validation.

KEY POINTS

· 25 ECV prediction models have been published; 14 were in the last 5 years.. · The Newman-Peacock model is currently the only one with sufficient validation for clinical use.. · Many newer models appear to perform better but await further validation..

Patient Experiences With Obstetric Counseling on Fetal Malpresentation

Introduction Fetal malpresentation is a complication of pregnancy in which the fetus does not present cephalically as required for vaginal birth. After a diagnosis is made, management options include cesarean section (CS) or external cephalic version (ECV). ECV is a procedure in which providers attempt to manually maneuver the fetus to cephalic position, allowing patients to attempt vaginal birth. Selecting between CS or ECV can be a complex and stressful decision, yet literature exploring patient perspectives on counseling of these options is limited. This study aims to describe patient perspectives on decision-making when diagnosed with fetal malpresentation. Methods We included English-speaking pregnant patients greater than 18 years of age diagnosed with malpresentation at 35-37 weeks' gestation. Patients who previously underwent CS or had maternal or fetal contraindications besides malpresentation to vaginal birth requiring CS were excluded. Semi-structured interviews were conducted with participants from four obstetric clinics in Baltimore, Maryland, at time of diagnosis. Themes were derived using data analysis in NVivo 11 (released 2015, Lumivero, USA). Results We recruited 10 participants (median age = 32 years, 90% Caucasian, 70% nulliparous, 50% chose ECV). We categorized our findings into the following themes: (1) facilitators and (2) barriers to deciding on malpresentation management, (3) participant priorities and values, and (4) other methods of malpresentation management. The participants identified incorporation of statistics and medical history into counseling as facilitators and the lack of information about ECV as a significant barrier. The participants prioritized fetal safety and, among those who chose ECV, a desire to avoid CS. Chiropractors, acupuncture, and moxibustion were identified as valuable additional methods of malpresentation management. Conclusion Overall, patients desire more information about ECV when diagnosed with fetal malpresentation. Uncertainty about ECV safety is a barrier to deciding between management options. Based on our findings, obstetric providers should provide comprehensive counseling on ECV and CS. Counseling should aim to demystify ECV and quantify risk in a patient-specific context. This will allow patients to make an informed decision on the management of fetal malpresentation that aligns with their goals for pregnancy.

External Validation of a Prediction Model for External Cephalic Version Success

External cephalic version (ECV) success correlates with numerous maternal and pregnancy factors. A prior study developed an ECV success prediction model based on body mass index, parity, placental location, and fetal presentation. We performed external validation of this model using a retrospective cohort of ECV procedures from a separate institution between July 2016 and December 2021. Four hundred thirty-four ECV procedures were performed, with a 44.4% success rate (95% CI 39.8-49.2%), which was similar to the derivation cohort (40.6%, 95% CI 37.7-43.5%, P=.16). There were significant differences in patients and practices between cohorts, including the rate of neuraxial anesthesia (83.5% derivation cohort vs 10.4% our cohort, P<.001). The area under the receiver operating characteristic curve (AUROC) was 0.70 (95% CI 0.65-0.75), which was similar to that in the derivation cohort (AUROC 0.67, 95% CI 0.63-0.70). These results suggest the published ECV prediction model's performance is generalizable outside the original study institution.

Vaginal fluid index - The fifth amniotic pocket

OBJECTIVE

The forebag is a pocket of amniotic fluid preceding the fetal presenting part. Herein we describe the feasibility of transvaginal measurements of the forebag and assess its correlation with the standard amniotic fluid index (AFI).

METHODS

A prospective study was carried out between January 2019 and July 2020. Eligible cases were women with singletons, vertex presentation, and normal AFI at term. We assessed the implementation and acceptance of a novel process in the clinical practice setting. Feasibility was assessed by using transvaginal ultrasound to measure the three orthogonal planes of the forebag. The vaginal fluid index (VFI) was defined as the volume composite of the three orthogonal planes. Correlations of the forebag measurements with both AFI and maximal vertical pocket were then calculated.

RESULTS

In total, 292 out of 305 (95.7%) women were enrolled. All participants completed both transabdominal and transvaginal ultrasound, of which the vaginal pocket was demonstrated in 266 (91.1%) cases. We found significant correlations, in both nulliparas and multiparas, between the vaginal pocket measurements and the VFI to both the AFI and maximal vertical pocket measurements (R = 0.38, P < 0.001; R = 0.3, P < 0.001, respectively).

CONCLUSION

We introduced a new ultrasound variable, the VFI, with a high feasibility rate. This may provide invaluable information for future decision making around the time of delivery.

Analysis of the Influence of Innovative Teaching Management Mode in Universities on Students' One-to-One Training and Psychotherapy

Objective

This study expects to investigate and verify the intervention effect of the university's innovative teaching management model on college students' resilience by implementing the university's innovative teaching management model for college students with low psychological resilience.

Method

The scientific scale is used to investigate the current level of college students' psychological resilience, and the development characteristics of college students' psychological resilience are obtained through statistical analysis. Based on the theoretical analysis of the application of psychological resilience intervention, combined with the theory of one-to-one tutoring and operational techniques, the university's innovative teaching management mode scheme is designed. The design adopts a quasi-experimental pre-experimental test to investigate and explore the intervention effect system of the university's innovative teaching management mode on college students' psychological resilience. In the intervention, each unit of activity is carried out in strict accordance with the established plan, and records and reflections are made at the end. One-to-one and face-to-face qualitative interviews were conducted with the subjects, and qualitative data were collected for qualitative analysis. Results/Discussion. Compared with the control group that did not receive the intervention, the psychological resilience of the subjects in the experimental group was significantly improved after receiving the intervention of the university's innovative teaching management model. The university's innovative teaching management model has a good intervention effect on the resilience of college students. The university's innovative teaching management model scheme compiled in this study integrates a variety of psychotherapy methods and combines one-to-one psychological counseling frameworks and techniques. It is an effective and easy-to-implement intervention scheme for college students' psychological resilience intervention.

Decision Tree Algorithm for Visual Art Design in a Psychotherapy System for College Students

With the development of society, psychological health becomes a basic standard for a college student to grow into a qualified person. This study is aimed at using data mining principles and methods to excavate the factors that lead to psychological problems of college students, to purposefully carry out psychological interventions, use visual art design methods to promote college students' psychological health treatment, and build a perfect system of college students' psychological treatment. Based on the theories of data mining, we built a data analysis model, elaborated the data preprocessing method, and applied the Apriori algorithm to analyze the data of obsessive-compulsive symptoms and interpersonal sensitivity symptoms, and various psychological problem attributes extracted the strong association rules and analyzed the results. Take advantage of the corresponding unique school environment and educational advantages, to build a set of mental health education methods suitable for modern college students, and truly enable them to obtain satisfactory psychological interventions in a reasonable art design treatment phase. Based on the above association pattern mining results, a series of preprocessing operations were performed on the data, and then, the Apriori algorithm was applied to discover the potential association relationships among 9 psychological dimension factors of college students, and then, the ID3 decision tree algorithm was used to construct a decision tree and pruning process, from which the classification rules of students' psychological problems were analyzed and discovered. These studies provide some practical reference basis for school counseling work.

A prospective study using an individualized nomogram to predict the success rate of external cephalic version

To establish a clinical-based nomogram for predicting the success rate of external cephalic version (ECV) through a prospective study. This was a single-center prospective study that collected eligible breech pregnant women. 152 participants were enrolled in the training cohort, who received ECV procedures performed by a single operator. We used the training cohort to establish regression equations and prediction models. These variables include maternal factors (age, operation gestational age, pre-pregnancy BMI (Body Mass Index), operation BMI, BMI increase, multipara), ultrasound factors (fetal weight estimation, amniotic fluid index, placental location, type of breech presentation, spinal position), and anesthesia. Univariate and multivariable analyses were used to screen the factors affecting the success of ECV. A nomogram scoring model was established based on these factors. And C-index, DCA (Decision Curve Analysis) and calibration curve, Hosmer–Lemeshow test was used to verify the prediction effect of the model. Finally, 33 participants were enrolled in the testing cohort who received ECV with an unrestricted operator. We used C-index, DCA (decision curve analysis), and Hosmer–Lemeshow to verify the application value of the prediction model. The calibration curves and ROC curves of both the training cohort and testing cohort are plotted for internal and external validation of the model. The ECV success rate of the training cohort was 62.5%. Univariate analysis showed that the predictors related to the success rate of ECV were age, BMI increase value, AFI (amniotic fluid index), breech type, placental location, spinal position, anesthesia, and multipara. The prediction thresholds of the corresponding indexes were calculated according to the Youden index. Multivariate logistic regression analysis showed that BMI increase ≥ 3.85 kg/m², AFI ≥ 10.6 cm, anesthesia, multipara, and non-anterior placenta were independent predictors of ECV success. Through the internal and external validation, it is confirmed that the model has a good calibration and prediction ability. Our nomogram has a good ability to predict the success rate of ECV.

Sedation with Propofol plus Paracetamol in External Cephalic Version: An Observational Study

Although the influence of neuraxial anesthesia or sedation with remifentanil in external cephalic version (ECV) is widely known, ECV results using propofol have not been previously analyzed. This study aimed to evaluate ECV outcomes when propofol was used. An observational analysis of ECV was performed between 1 January 2018 and 31 December 2020. ECV was accomplished with tocolysis and propofol. One hundred and thirty-one pregnant women were recruited. The propofol mean dose was 156.1 mg (SD 6.1). A cephalic presentation was achieved in 61.1% (80/131) of the pregnant women. In total, 56.7% (38/67) of pregnant women with cephalic presentation at labor had a spontaneous delivery, 26.9% (18/67) had an operative delivery, and an intrapartum urgent cesarean section was performed in 16.4% (11/67). In total, 46 pregnant women (35.9%) were scheduled for an elective cesarean section due to non-cephalic presentation. The emergency cesarean section rate during the following 24 h was 10.7% (14/131). A major ECV complication arose in 15 cases (11.5%). ECV outcomes when propofol was used seems to be similar to those with other anesthetic adjunct, so sedation with propofol could be an adequate option for ECV. More studies are needed to compare its effectiveness with neuraxial techniques.

Effect of acupressure at the BL67 spot on the spontaneous rotation of fetus with breech presentation: A randomized controlled trial

BACKGROUND

Breech is a common fetal presentation in preterm pregnancies. This study aimed to investigate the effect of acupressure at the BL67 point on the spontaneous rotation of fetus with breech presentation.

METHODS

An unblind, two-armed randomized controlled trial was carried out from September 2017 to April 2020. Research participants were 138 pregnant women at 32 to 35 weeks of gestational age that had fetal breech presentation confirmed by ultrasound. They were randomly assigned into intervention and control groups (n=69 in each group). The intervention group received acupressure at the BL67 point on both feet for 10 minutes daily and for two consecutive weeks. The control group received routine care. Demographic and midwifery data questionnaires were used for data collection.

RESULTS

The spontaneous rotation of fetus with breech presentation into cephalic was observed in the majority of participants in the intervention group (82.6%) compared to the control group (17.4%) (p<0.001). Statistically significant differences in the fetal presentation at delivery was observed between the groups (84.1% cephalic vs. 18.8% breech, p<0.001). Regarding the type of delivery, cesarean section was reported mostly (85.5%) in the control group compared to the intervention group (21.7%) (p<0.001). However, the first- and fifth-minute Apgar scores of newborns had no statistically significant differences between the groups (p=0.773).

CONCLUSION

It is suggested to incorporate acupressure at the BL67 point into the care process for pregnant women to help with the reduction of the rate of cesarean section and avoid its related complications.

Success rate of external cephalic version in relation to the woman's body mass index and other factors-a population-based cohort study

INTRODUCTION

The aim of this study was to evaluate the impact of women's body mass index (BMI) on the probability of a successful external cephalic version (ECV).

MATERIAL AND METHODS

A retrospective population-based observational study including all women that underwent an ECV in the southeast region of Sweden from January 2014 to December 2019. Data were collected from electronic medical records, Obstetrix, Cerner. The women were divided into BMI categories according to the World Health Organization classification. Women with a BMI below 25 kg/m² formed the reference group. Crude and adjusted odds ratios for unsuccessful ECV in each BMI group were calculated using binary logistic regression. Furthermore, the association between maternal characteristics and clinical and ultrasound variables at the time of the ECV and unsuccessful ECV was evaluated.

RESULTS

A total of 2331 women were included. The overall success rate of ECV was 53.4%. Women with a BMI below 25 kg/m² had a success rate of 51.3% whereas obese women had a success rate of 58.6%. The risk of an unsuccessful ECV among obese women (BMI ≥30 kg/m² ) had an OR of 0.74 (95% CI 0.59-0.94) compared with women with a BMI below 25 kg/m² . After adjusting for suitable confounding factors, the association was no longer significant. Higher maternal age, multiparity, higher gestational age, posterior placenta position, polyhydramnios and higher estimated weight of the fetus at the ECV significantly decreased the risk of an unsuccessful ECV.

CONCLUSIONS

Maternal obesity does not seem to negatively influence the success rate of ECV. This is a finding that may encourage both caregivers and obese pregnant women to consider an ECV and so avoid a planned cesarean section for breech presentation in this group.

Breech progression angle: new feasible and reliable transperineal ultrasound parameter for assessment of fetal breech descent in birth canal

OBJECTIVE

To assess the feasibility and reliability of transperineal ultrasound in the assessment of fetal breech descent in the birth canal, by measuring the breech progression angle (BPA).

METHODS

Women with a singleton pregnancy with the fetus in breech presentation between 34 and 41 weeks' gestation were recruited. Transperineal ultrasound images were acquired in the midsagittal view for each woman, twice by one operator and once by another. Each operator measured the BPA after anonymization of the transperineal ultrasound images. BPA was defined as the angle between a line running along the long axis of the pubic symphysis and another line extending from the most inferior portion of the pubic symphysis tangentially to the lowest recognizable fetal part in the maternal pelvis. Each operator was blinded to all other measurements performed for each woman. Intra- and interobserver reproducibility of BPA measurement was evaluated using the intraclass correlation coefficient (ICC). To investigate the presence of any bias, intra- and interobserver agreement was also analyzed using Bland-Altman analysis. Student's t-test and Levene's W₀ test were used to investigate whether a number of different clinical factors had an effect on systematic differences and homogeneity, respectively, between BPA measurements.

RESULTS

Overall, 44 women were included in the analysis. BPA was measured successfully by both operators on all images. Both intra- and interobserver agreement analyses showed excellent reproducibility in BPA measurement, with ICCs of 0.88 (95% CI, 0.80-0.93) and 0.83 (95% CI, 0.71-0.90), respectively. The mean difference between measurements was 0.4° (95% CI, -1.4 to 2.2°) for intraobserver repeatability and -0.4° (95% CI, -2.6 to 1.8°) for interobserver repeatability. The upper limits of agreement were 12.0° (95% CI, 8.9-15.1°) and 13.6° (95% CI, 9.9-17.3°) for intra- and interobserver repeatability, respectively. The lower limits of agreement were -11.2° (95% CI, -14.3 to -8.1°) and -14.4° (95% CI, -18.2 to -10.7°) for intra- and interobserver repeatability, respectively. No systematic difference between BPA measurements was found on either intra- or interobserver agreement analysis. None of the clinical factors examined (maternal body mass index, maternal age, gestational age at the ultrasound scan and parity) showed a statistically significant effect on intra- or interobserver reliability.

CONCLUSIONS

BPA represents a new feasible and highly reproducible measurement for the evaluation of fetal breech descent in the birth canal. Future studies assessing its usefulness in the prediction of successful external cephalic version and breech vaginal delivery are needed. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Assessment of the Successful External Cephalic Version Prognostic Parameters Effect on Final Mode of Delivery

Aim

This study aims to evaluate the prognostic parameters of successful approach for an external cephalic version (ECV) procedure by considering the vaginal delivery as the optimal mode of delivery.

Methodology

A retrospective cohort study was done during June 2019 in the obstetrics and gynecology department at King Abdulaziz University Hospital. Data were collected between May 2009 and May 2019 and included all pregnant women who were candidates for the ECV. The primary objective was to assess the final mode of delivery in relation to the outcome of ECV followed by the secondary objective which was the prognostic parameters of the ECV procedure (body mass index, amniotic fluid index, parity, estimated fetal weight). Additional variables were maternal age, placental position and ethnicity.

Results

We have studied 86 pregnant women with ECV attempts the overall ECV success rate was for 46 women (59.7%). For the final mode of delivery, after a successful ECV procedure, 40 women (87%) whom had spontaneous vaginal delivery, in association to successful ECV, the prognostic parameters recorded the highest success rate were multiparous 35 (76.1%), body mass index between 25 and 29.9 (53.1%), women older than 30 years old (60.9%), gestational age between 37 to 39.6 weeks (56.5%). Posterior placental location 55.6%, estimated fetal weight more than 2500 (73.9%).

Conclusion

Successful ECV cases have recorded a significant increase in the incidence of spontaneous vaginal delivery and the outcome of ECV which is affected by many prognostic parameters such as parity, maternal age, gestational age, body mass index, amniotic fluid index (AFI) and estimated fetal weight (EFW).  

A Multivariable Predictive Model for Success of External Cephalic Version

OBJECTIVE

To create a prediction model for external cephalic version (ECV) success using objective patient characteristics.

METHODS

This retrospective study included pregnant individuals of at least 18 years of age with a nonanomalous, singleton gestation who underwent an ECV attempt between 2006 and 2016 at a single quaternary care hospital. Variables assessed included maternal age, height, weight, body mass index (BMI), parity, fetal sex, gestational age, estimated fetal weight, type of fetal malpresentation, placental location, and amniotic fluid volume. Univariable and multivariable logistic regression models were used to determine the association of patient characteristics with ECV success. Estimated odds ratios and corresponding 95% CIs were calculated for each variable, and backward elimination and bootstrapping were used to find a parsimonious model for ECV success with the highest discriminatory capacity (as determined by the area under the receiver operating characteristic curve [AUC]). This model was evaluated with a calibration curve across deciles of success.

RESULTS

A total of 1,138 individuals underwent an ECV attempt and were included in this analysis. The overall ECV success frequency was 40.6%. Factors significantly associated with ECV success were maternal age, parity, placental location, estimated fetal weight, and type of fetal malpresentation. A final model with BMI, parity, placental location, and type of fetal malpresentation had the highest AUC (0.667 [95% CI 0.634-0.701]), resulted in good calibration, and is represented by the following equation: 1/[1+e-x] where x=1.1726-0.0314 (BMI)-0.9299 (nulliparity)+1.0218 (transverse or oblique presentation at ECV)-0.5113 (anterior placenta). An interactive version of this equation was created and can be accessed at www.ecvcalculator.com.

CONCLUSION

A prediction model that estimates the probability of ECV success was created and internally validated. This model incorporates easily obtainable and objective patient factors known before ECV and may be used in decision making and patient counseling about ECV.

Development of prediction models for successful external cephalic version and delivery outcome

OBJECTIVE

To develop prediction models for the chance of successful external cephalic version (ECV) and delivery outcome.

STUDY DESIGN

This is a single-center retrospective study including 350 pregnant women with a singleton non-cephalic pregnancy at or after 36 weeks of gestational age. We selected 22 factors for ECV prediction and 21 for delivery outcome after successful ECV prediction as candidate predictors. Multivariable logistic regression with a stepwise backward selection procedure was used to construct a prediction model for the chance of successful ECV and the other for the delivery outcome. The discrimination and calibration of the models were assessed and internal validation was done with bootstrapping.

RESULTS

ECV was successfully performed in 232 cases (66.3%) among 343 women. Eight predictive factors were identified to be associated with a successful ECV: Gestational week at ECV < 39 weeks, multiparous, BMI before pregnancy < 22 kg/m³, palpable fetal head, breech engagement, larger AFI, larger BPD and posterior placenta. This model showed good calibration and good discrimination (c-statistic = 0.82, 95% CI 0.76-0.88). Six predictive factors were identified to be associated with vaginal delivery after successful ECV: age < 35, multiparous, BMI before pregnancy < 22 kg/m³, anterior placenta, lateral placenta and none-front fetal spine position. This model showed fair discrimination (c-statistic = 0.79, 95% CI 0.72-0.85). However, its calibration was not so satisfactory especially when the predicted probability was low.

CONCLUSION

We validated a prediction model for ECV and delivery outcome, showing that the model's overall performance is good. This can be used in clinical practice after external validation.

Patient characteristics associated with complications of external cephalic version

BACKGROUND

Patient characteristics associated with external cephalic version success are well documented; however, the association between patient characteristics and the likelihood of external cephalic version complications is poorly understood.

OBJECTIVE

This study aimed to assess the frequency of patient characteristics associated with complications that lead to unanticipated delivery during external cephalic version.

STUDY DESIGN

This retrospective study included pregnant women aged at least 18 years with singleton gestations who underwent an external cephalic version attempt between 2006 and 2016 at a single quaternary care center. External cephalic version complications were defined as persistent nonreassuring fetal status, placental abruption, labor, spontaneous rupture of membranes, and umbilical cord prolapse. Complications were only considered if they led to unanticipated induction or cesarean delivery within 24 hours of external cephalic version. Patient characteristics including maternal age, height, weight, body mass index, parity, fetal sex, gestational age, estimated fetal weight, the type of fetal malpresentation, and placental location were analyzed for their association with external cephalic version complications using univariable analysis and multivariable logistic regressions.

RESULTS

Among the 1138 patients included in this analysis, external cephalic version complications occurred in 6.7% (n=76). These complications (not mutually exclusive) included nonreassuring fetal status (4.8%, n=55), placental abruption (1.6%, n=18), labor (1.0%, n=11), spontaneous rupture of membranes (0.6%, n=7), and cord prolapse (0.1%, n=1). Neonatal outcomes for those with complications included intensive care unit admission (10.5%, n=8), 5-minute Apgar scores <5 (1.3%, n=1), cord arterial pH <7 (6.6%, n=5), head cooling (1.3%, n=1), and anemia (6.6%, n=5). There were no perinatal deaths. In multivariable analysis, higher body mass index (adjusted odds ratio, 0.90 per kg/m²; 95% confidence interval, 0.84-0.97) and estimated fetal weight (adjusted odds ratio, 0.998 per gram; 95% confidence interval 0.998-0.999) were associated with decreased likelihood of experiencing external cephalic version complications, whereas greater gestational age at procedure (adjusted odds ratio, 1.95 per week; 95% confidence interval, 1.4-2.7) and anterior placental location (adjusted odds ratio, 2.0; 95% confidence interval, 1.1-3.7) were associated with increased likelihood of experiencing external cephalic version complications.

CONCLUSION

In this large series, complications that led to delivery during external cephalic version occurred in 6.7% patients and were associated with body mass index, estimated fetal weight, gestational age, and placental location.

External cephalic version: Predictors for success

OBJECTIVES

The objective of this study was to identify the factors predictive of the success of external cephalic version (ECV).

METHODS

A single-centre retrospective observational study was performed in the maternity ward of the Angers University Hospital, France, between January 2010 and May 2020. The study included all patients (n = 613) for whom an ECV was performed for a breech or transverse foetus. The primary endpoint was measured by the success of the ECV, defined by the visualisation, using pelvic ultrasound, of the foetus in cephalic presentation immediately after the manoeuvre. Following to the ECV, the cohort was separated into two groups; ECV Success and ECV Failure. In order to determine the predictive factors of success, a logistic regression model was performed, including the parameters of: parity, foetal presentation during ECV, the side of the foetal back, placental location, type of operator and maternal age. The results are presented as (odds ratio [confidence intervals]; p-value). The significance threshold was defined by a p-value < 0.05.

RESULTS

The ECV success rate was 21.4% (131/613). The factors predictive of the success of ECV were: transverse foetal presentation (2.7 [1.3-5.6]; p<0.01); a senior physician operator (1.6 [1.2-2]; p<0.01); multiparity (1.6 [1.2-2]; p<0.01); non anterior placental localization (1.4 [1.1-2]; p<0.01). A number of attempts greater than 3 were significantly associated with reduced chances of success (0.3 [0.2-0.4]; p<0.01).

CONCLUSION

The study shows that transverse foetal presentation, a senior physician operator, multiparity, as well as a non-anterior placental location are factors predictive of the success of ECV. Knowledge of these factors can improve the information given to patients.

Association of Persistent Breech Presentation With External Cephalic Version Success

OBJECTIVE

To evaluate a possible correlation between a new variable-persistent breech presentation-and the success rate of external cephalic version (ECV).

METHODS

This was a retrospective study of ECVs performed from January 2008 through January 2019 in an Israeli tertiary care hospital. The study group included all pregnant women who underwent an ECV at or beyond 37 weeks of gestation. Persistent breech presentation was defined as persistent breech presentation during all ultrasound examinations performed between the anatomy scan at mid-pregnancy and the gestational week when ECV was attempted. Women in whom cephalic presentation was documented at least once on these ultrasound examinations were defined as not having persistent breech presentation. The primary outcome was defined as the success rate of ECV, and the secondary outcome was defined as the mode of delivery after a successful ECV.

RESULTS

We identified 1,271 women with breech presentation during the study period. They had undergone median of five (range 2-7) ultrasound examinations. External cephalic version was attempted in 684 women (53.8%), with a success rate of 61.5%. External cephalic version succeeded in 19.6% of those with persistent breech presentation (44/224) compared with 82.0% (377/460) of those without persistent breech presentation (P<.001). Ultimately, women with persistent breech presentation and successful ECV experienced a lower rate of vaginal delivery (27.3% vs 79%, P<.001), and a higher rate of instrumental (29% vs 13%, P<.001) and cesarean deliveries (43% vs 7%, P<.001) compared with the nonpersistent breech presentation group. The rate of noninstrumental vaginal delivery among women with persistent breech presentation, regardless of ECV, was 5.4%.

CONCLUSION

Women with persistent breech presentation experienced a high rate of ECV failure and a low rate of spontaneous vaginal delivery.

Comparison of Multivariable Logistic Regression and Other Machine Learning Algorithms for Prognostic Prediction Studies in Pregnancy Care: Systematic Review and Meta-Analysis

Background

Predictions in pregnancy care are complex because of interactions among multiple factors. Hence, pregnancy outcomes are not easily predicted by a single predictor using only one algorithm or modeling method.

Objective

This study aims to review and compare the predictive performances between logistic regression (LR) and other machine learning algorithms for developing or validating a multivariable prognostic prediction model for pregnancy care to inform clinicians’ decision making.

Methods

Research articles from MEDLINE, Scopus, Web of Science, and Google Scholar were reviewed following several guidelines for a prognostic prediction study, including a risk of bias (ROB) assessment. We report the results based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were primarily framed as PICOTS (population, index, comparator, outcomes, timing, and setting): Population: men or women in procreative management, pregnant women, and fetuses or newborns; Index: multivariable prognostic prediction models using non-LR algorithms for risk classification to inform clinicians’ decision making; Comparator: the models applying an LR; Outcomes: pregnancy-related outcomes of procreation or pregnancy outcomes for pregnant women and fetuses or newborns; Timing: pre-, inter-, and peripregnancy periods (predictors), at the pregnancy, delivery, and either puerperal or neonatal period (outcome), and either short- or long-term prognoses (time interval); and Setting: primary care or hospital. The results were synthesized by reporting study characteristics and ROBs and by random effects modeling of the difference of the logit area under the receiver operating characteristic curve of each non-LR model compared with the LR model for the same pregnancy outcomes. We also reported between-study heterogeneity by using τ² and I².

Results

Of the 2093 records, we included 142 studies for the systematic review and 62 studies for a meta-analysis. Most prediction models used LR (92/142, 64.8%) and artificial neural networks (20/142, 14.1%) among non-LR algorithms. Only 16.9% (24/142) of studies had a low ROB. A total of 2 non-LR algorithms from low ROB studies significantly outperformed LR. The first algorithm was a random forest for preterm delivery (logit AUROC 2.51, 95% CI 1.49-3.53; I²=86%; τ²=0.77) and pre-eclampsia (logit AUROC 1.2, 95% CI 0.72-1.67; I²=75%; τ²=0.09). The second algorithm was gradient boosting for cesarean section (logit AUROC 2.26, 95% CI 1.39-3.13; I²=75%; τ²=0.43) and gestational diabetes (logit AUROC 1.03, 95% CI 0.69-1.37; I²=83%; τ²=0.07).

Conclusions

Prediction models with the best performances across studies were not necessarily those that used LR but also used random forest and gradient boosting that also performed well. We recommend a reanalysis of existing LR models for several pregnancy outcomes by comparing them with those algorithms that apply standard guidelines.

Trial Registration

PROSPERO (International Prospective Register of Systematic Reviews) CRD42019136106; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=136106

External cephalic version: Predictors of success and influence on caesarean rates

OBJECTIVE

To evaluate the success rate of external cephalic version, predictive factors for success of this maneuver and to examine how it affects mode of delivery, pregnancy and neonatal outcome rates.

STUDY DESIGN

Retrospective cross-sectional study performed in a tertiary care university hospital between January 2002 and June 2018. A total of 324 ECVs were performed in 321 pregnancies. Maternal and ultrasound data, procedure-related factors, birth characteristics and neonatal data were collected. Absolute and relative frequencies were used for descriptive analysis and the chi-square test for comparative analysis. Odds ratios with 95 % confidence intervals were calculated.

RESULTS

The overall success rate of the procedure was 33,3%. Multiparity, transverse lie, unengaged breech presentation, low body mass index, soft uterus and palpable fetal head were independent risk factors for success. No statistically significant association was found with other variables. Routine use of ECV allowed a reduction in cesarean delivery rates for breech presentation, with no increase in maternal or neonatal morbidity. Operative delivery rates after successful ECV were similar to those of the general population.

DISCUSSION AND CONCLUSION

Despite a relatively low overall success rate, routine use of ECV can result in reduced cesarean delivery rates with similar perinatal outcomes. Conveyed information on the success rate of ECV can be adapted to individual patient characteristics.

Current Approach for External Cephalic Version in Germany

Introduction Fetal breech presentation at terms occurs in 3 - 6% of pregnancies. External cephalic version can reduce the number of cesarean sections and vaginal breech deliveries. Different approaches are used to carry out external cephalic version. This study looked at the different approaches used in Germany and compared the approach used with the recommendations given in German and international guidelines. Material and Methods An anonymized online survey of 234 hospitals in Germany was carried out in 2018. In addition to asking about hospital structures, questions also focused on how external version was carried out in practice (preparations, tocolysis, anesthetics, etc.), on relative and absolute contraindications and on the success rate. Results 37.2% of the hospitals approached for the survey participated in the study. Of these, 98.8% performed external version procedures. The majority of participating hospitals were university hospitals (26.4%) and maximum care hospitals (35.6%) with an average number of more than 2000 births per year (60.9%). External cephalic version is the preferred (61.7%) obstetrical procedure to deal with breech presentation, rather than vaginal breech birth or primary cesarean section. 45.8% of respondents carry out external version procedures on an outpatient basis, and 42.1% of hospitals perform the procedure as an inpatient intervention, especially from the 37th week of gestation. Prior to performing an external version procedure, 21.6% of surveyed institutions carry out a vaginal examination to evaluate possible fixation of the fetal rump. 95.5% of institutions used fenoterol for tocolytic therapy; the majority using it for continuous tocolysis (70.2%). 1 - 3 attempts at external version (8.4%) were usually carried out by a specific senior physician. In most cases, no analgesics were administered. The reported rate of emergency cesarean sections was very low. The most common indication for emergency C-section was pathological CTG (56,7%). The assessment of relative and absolute contraindications varied, depending on the surveyed hospital. 67.5% asked patients to empty their bladders before carrying out external version, while 10.8% carried out external version when the bladder was filled. The reported success rate was more than 45%. After successful version, only 14.8% of hospitals arranged for patients to wear an abdominal binder. For 32.4%, the decision to apply an abdominal binder was taken on a case-by-case basis. Conclusion The approach used in Germany to carry out external cephalic version is based on the (expired) German guideline on breech presentation. Based on the evidence obtained, a number of individual recommendations should be re-evaluated. More recent international guidelines could be useful to update the standard procedure.

Prediction model of success for external cephalic version. Complications and perinatal outcomes after a successful version

AIM

External cephalic version (ECV) is an effective and safe technique for avoiding breech presentation at birth. However, it continues rejected by many women. The aim of this study is to develop a predictive model of success of external cephalic version, determine the safety of the technique and perinatal outcomes after successful version.

METHODS

Data from 317 versions performed over a 6-year period were collected. Different clinical and ultrasound variables, complications, vaginal delivery after successful version and perinatal outcomes were analyzed.

RESULTS

The overall success rate was 72% (229 of 317 versions). The variables most related to success were parity, placental location, amniotic fluid volume, fetal sex, fetal head palpation and descent of the presenting part. A model for calculating the probability of success was developed in which to input parity, placentation and amniotic fluid data. The model correctly classified 98.8% of successful technique and 74% of all women. Complications were very few and mostly mild. Of women who had success, 77% (163 of 212) had a vaginal birth. No differences between neonatal outcomes were found.

CONCLUSION

External cephalic version is a successful, safe technique with a high rate of subsequent vaginal delivery. A success prediction model based on some very easily obtained variables can personalize the probability of success.