Correlation of Cervical Length Obtained from Transperineal Ultrasonography, Transvaginal Ultrasonography and Digital Examination

Abstract

Objectives To evaluate the correlation of cervical length measurements obtained from digital examination, transperineal, and transvaginal ultrasonography techniques and to determine discomfort arising from each technique.

Design                Cross-sectional study.

Setting                Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology,

Faculty of Medicine Siriraj Hospital, Mahidol University.

Subjects Fifty pregnant women at 37 weeks’ gestation or more who agreed to participate were enrolled.

Methods Cervical length was measured in each woman by both transperineal and transvaginal ultrasonography by experienced staff using standard technique and criteria. Digital examination was performed to evaluate cervical length without knowledge of sonographic results. Discomfort arising from each technique was assessed using visual analog scale.

Main outcome measures Correlation between cervical length measurements from each technique.

Results               Cervical length measurement from digital examination was the lowest among the 3

techniques and measurements from transperineal and transvaginal ultrasonography were comparable. There were significant correlations of cervical length measured in each technique. Results from transperineal and transvaginal ultrasonography demonstrated the strongest correlation (r 0.73, p < 0.001). Significant higher discomfort score was demonstrated in digital examination while there was no significant difference between transperineal and transvaginal techniques.

Conclusion There were significant correlations between cervical length measurements from digital examination, transperineal and transvaginal sonographic assessments. Transperineal ultrasonography showed low discomfort. Such technique can be considered an alternative method when potential complications from digital examination or transvaginal ultrasonography of the cervix are anticipated and where resources are limited.