Predictors of Cephalic Vaginal Delivery Following External Cephalic Version: An Eight-Year Single-Centre Study of 447 Cases

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.

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.

Comparison of Nitroglycerin and Terbutaline for External Cephalic Version in Women Who Received Neuraxial Anesthesia: A Retrospective Analysis

External cephalic version is a technique that decreases the need for cesarean delivery in patients with breech presentation. Several techniques exist to increase the success of external cephalic version; however, there are no studies comparing different tocolytics in patients who also received neuraxial anesthesia. We, therefore, performed a review of 198 patients who presented for external cephalic version and compared their success rates based on the tocolytic medication utilized. The external cephalic version success rate for patients who received terbutaline was significantly higher than for those who received nitroglycerin (N [%]: 57 [65.6] terbutaline group versus 40 [36.0] nitroglycerin group; P < .001).

Revisiting the management of term breech presentation: a proposal for overcoming some of the controversies

Background

The debate surrounding the management of term breech presentation has excessively focused on the mode of delivery. Indeed, a steady decline in the rate of vaginal breech delivery has been observed over the last three decades, and the soundness of the vaginal route was seriously challenged at the beginning of the 2000s. However, associations between adverse perinatal outcomes and antenatal risk factors have been observed in foetuses that remain in the breech presentation in late gestation, confirming older data and raising the question of the role of these antenatal risk factors in adverse perinatal outcomes. Thus, aspects beyond the mode of delivery must be considered regarding the awareness and adequate management of such situations in term breech pregnancies.

Main body

In the context of the most recent meta-analysis and with the publication of large-scale epidemiologic studies from medical birth registries in countries that have not abruptly altered their criteria for individual decision-making regarding the breech delivery mode, the currently available data provide essential clues to understanding the underlying maternal-foetal conditions beyond the delivery mode that play a role in perinatal outcomes, such as foetal growth restriction and gestational diabetes mellitus. In view of such data, an accurate evaluation of these underlying conditions is necessary in cases of persistent term breech presentation. Timely breech detection, estimated foetal weight/growth curves and foetal/maternal well-being should be considered along with these possible antenatal risk factors; a thorough analysis of foetal presentation and an evaluation of the possible benefit of external cephalic version and pelvic adequacy in each specific situation of persistent breech presentation should be performed.

Conclusion

The adequate management of term breech pregnancies requires screening and the efficient identification of breech presentation at 36 weeks of gestation, followed by thorough evaluations of foetal weight, growth and mobility, while obstetric history, antenatal gestational disorders and pelvis size/conformation are considered. The management plan, including external cephalic version and follow-up based on the maternal/foetal condition and potentially associated disorders, should be organized on a case-by-case basis by a skilled team after the woman is informed and helped to make a reasoned decision regarding delivery route.

Introduction of a dedicated team increases the success rate of external cephalic version: A prospective cohort study

OBJECTIVE

To investigate the influence of a dedicated team on the success rate of external cephalic version and mode of delivery.

STUDY DESIGN

This prospective cohort study included 673 women with a singleton fetus in breech presentation who underwent external cephalic version between January 2013 and December 2017 at Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. In January 2014, a dedicated team consisting of six gynaecologists and six midwives was introduced at the study clinic. The success rate of external cephalic version and mode of delivery were analysed. In addition, predictors for success were examined by logistic regression analysis. Successful external cephalic version was defined as fetal cephalic presentation immediately following the procedure.

RESULTS

Following the introduction of a dedicated team in 2014, the success rate of external cephalic version increased from 39.8% in 2013 to 69.5% in 2017 (p < 0.001), with the greatest increase in nulliparous women (from 23.5% to 58.5%, p = 0.002). Over the 5-year study period, the vaginal delivery rate after external cephalic version increased from 43% in 2013 to 71% in 2017 (p < 0.05). The rate of caesarean section after external cephalic version decreased from 55% to 27% (p < 0.05). Anterior placenta [odds ratio (OR) 0.7, 95% confidence interval (CI) 0.48‒0.97] and complete breech (OR 0.2, 95% CI 0.07‒0.90) were significantly associated with a lower success rate.

CONCLUSIONS

This study showed that introduction of a dedicated team led to a significant increase in the success rate of external cephalic version, and a significant decrease in the rate of caesarean section for women presenting with breech in pregnancy.