Facteurs de réussite d’une version par manœuvre externe : étude rétrospective de 439 cas

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.

[Impact of the external cephalic version on the obstetrical prognosis in a team with a high success rate of vaginal delivery in breech presentation]

OBJECTIVES

To analyse the impact of external cephalic version (ECV) on caesarean section rate in a team with a high success rate of vaginal delivery in breech presentation.

MATERIALS AND METHODS

Retrospective monocentric study including 298 patients with a breech presentations between 33 and 35weeks of amenorrhea followed at our university hospital and delivered after 35weeks, between 1st January 2011 and 31st December 2013. Patients were divided into 2 groups: planned ECV (n=216 patients) versus no planned ECV (n=57 patients).

RESULTS

Our rate of successful vaginal breech delivery over the period of the study was 61.1%. We performed 165 ECV, with a 21.8% success rate. The average term of the attempt of ECV was 36.7weeks of amenorrhea. The caesarean section rate was not significantly different in the planned ECV group, even after adjustment on age, parity and previous caesarean delivery (adjusted OR=1.67 [0.77-3.61]). Attempt of ECV did not reduce the number of breech presentation at delivery (61.1% versus 61.4% [P=0.55]).

CONCLUSION

Planned ECV in our center with a high level of breech vaginal delivery did not significantly impact our cesarean section rate.

Atosiban vs. ritodrine as a tocolytic in external cephalic version at term: a prospective cohort study

OBJECTIVE

To compare the success rate of external cephalic version (ECV) at term using ritodrine or atosiban as a tocolytic agent.

STUDY DESIGN

Prospective cohort study with a sample of 236 pregnant women with a breech presentation at term, from November 2006 to March 2008. Data have been analyzed from the moment the cephalic version is performed until the time of delivery.

RESULTS

ECV success rate using ritodrine as a tocolytic agent was 56.8% compared to 31.4% with atosiban. Ritodrine increases the version success potential more significantly than atosiban (P<0.05). In both cases, the use of ECV reduced the rate of cesarean sections, although a higher number of versions are required with atosiban [numbers needed to treat (NNT)=9.08] to avoid a cesarean section compared to ritodrine (NNT=3.41).

CONCLUSIONS

Ritodrine seems better than atosiban as tocolytic agent for ECVs.