Development and validation of a clinical score to predict the probability of successful procedure in women undergoing external cephalic version

Abstract

Introduction

External Cephalic Version (ECV) reduces breech presentation at term and thus contribute to the reduction of cesarean section. This study was done to determine the factors associated with the successful ECV in women with breech presentation after 36 weeks’ gestation and also to develop and validate a clinical score which could be utilized for individual patient counseling in future.

Methods

This was a retrospective cohort study conducted in a tertiary care center and teaching hospital in south India. Prospectively collected data from the register maintained for all ECVs performed on pregnant women with breech presentation at or more than 36 weeks’ gestation. Clinical and ultrasound parameters at the time of performing the procedure were used in the analysis. Multiple logistic regression with a stepwise backward selection procedure was used selecting potential variable to construct the model and internal validation was done with bootstrapping. Primary outcome was successful ECV defined as cephalic presentation at the end of the procedure

Results

Among 611 women who underwent ECV, it was successful in 70.4%. In the multiple logistic regression model, multiparity (OR4.48), AFI ≥ 7 (OR = 3.06), type of breech, posterior placental location (OR = 1.57), sacro-anterior position of breech (OR = 2.83), normal uterine tone (OR = 1.82) and fetal pole not engaged (OR = 2.82) were found to be predictive of successful ECV with good discrimination (AUC = 0.782) and acceptable calibration. Combining these factors from the model a predictive score (score 0–13) is proposed for clinical utility.

Conclusions

Combining clinical and ultrasound parameters into a predictive score, which is simple and effective, could be utilized in the clinical practice, once validated externally.

Keywords:

• Breech presentation
• cesarean section
• cohort study
• external cephalic version
• predictive score

Ethical approval

All procedures performed in this study were done with the ethical standards set by the Institute Scientific Advisory and Ethical Committee (Human Studies), in accordance with the 1964 Helsinki declaration and its later amendments. Since this we collected the data of the patients identified, from the registers, a waiver of consent and the protocol for this study was approved by the Institute Ethics Committee (Human Studies (Approval number: JIP/IEC/2016/24/809 dated 31 March 2016)).

Disclosure statement

No potential conflict of interest was reported by the authors.

Contribution to authorship

AK, KS and SN conceived the study. All authors contributed to the design. AK and KA carried out the data collection and guarantees data integrity. AK and RA performed statistical analyses. KA, SN and RA reviewed the analysis and AK & KA wrote the first draft. All authors contributed to revising and finalization of the manuscript. AK (corresponding author) guarantees all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.