RELIABILITIES OF THE SONOGRAPHIC EVALUATION FOR CERVICAL LENGTH AND ELASTOGRAPHY WITH PELVIC PARAMETERS IN TERM PREGNANCY BY VARIOUS LEVELS OF EXPERIENCED OPERATORS

Problem statement: To assess the reliability of sonographic measurements of six cervical and pelvic parameters among three sonographers with varying levels of experience.

Methods: A cross-sectional study was conducted on pregnant women with gestational age of 39 weeks or more. Each pregnant women was examined by two sonographers with different levels of experience. The six parameters were measured, including cervical length (CL), cervical strain elastography (extrinsic type), posterior cervical angle (PCA), fetal head to perineum distance (FHPD), fetal head to pubis symphysis distance (FHSD), and angle of progression (AOP). Intraobserver and interobserver reliability were assessed using intraclass correlation coefficient (ICC) with a 95% confidence interval. The correlation between the values of parameters were analyzed by Pearson pairwise correlation coefficients.

Results: A total of 66 pregnant women were enrolled. We found excellent intraobserver reliability for measurements of CL, PCA, FHPD, FHSD, and AOP and good to excellent intraobserver reliability for cervical strain values at regions endocervical canal (CEC) and entire cervix (CEX). Interobserver reliability was excellent for all pelvic parameters except FHPD. Strain values were moderate to excellent at the area of internal os. A significant negative correlation between CL and strain values at internal os region was observed.

Conclusions: The pelvic parameters have excellent intra- and interobserver reliabilities excepted for FHPD. A high reproducibility of CL and cervical strain elastography at internal os level with negative correlation between these two parameters might play an important role to predict successful induction of labor.