Intrapartum measurement of cervical dilatation using translabial 3-dimensional ultrasonography: correlation with digital examination and interobserver and intraobserver agreement assessment.
OBJECTIVE
The purpose of this study was to determine the accuracy and reproducibility of intrapartum translabial 3-dimensional (3D) ultrasonographic measurements of cervical dilatation during labor.


METHODS
A prospective observational study was conducted. Three-dimensional ultrasonographic volume data sets from 52 patients were collected during labor and stored. Later, all volumes were randomly reviewed twice offline by 2 examiners blinded to previous clinical and ultrasonographic measurements. The correlation with delivery room personnel digital vaginal examinations and interobserver and intraobserver agreement were determined.


RESULTS
Twenty-four patients were examined during the latent phase (0- to 4-cm cervical dilatation), and 28 patients were examined during the active phase (5- to 10-cm cervical dilatation). Translabial 3D ultrasonographic measurements of the cervical mean and maximal diameters and inner cervical area showed a positive correlation with digital vaginal examinations (r(2) = 0.609, 0.587, and 0.469, respectively; all P < .001). The interobserver mean differences +/- SD between paired measurements for the mean and maximal cervical dilatation and inner cervical area were 0.11 +/- 0.49 cm, 0.12 +/- 0.48 cm, and -0.22 +/- 5.69 cm(2), and the intraclass correlation coefficients (ICCs) were 0.82, 0.85, and 0.87. The intraobserver mean differences between paired measurements of the mean and maximal cervical dilatation and inner cervical area were 0.002 +/- 1.15 cm, 0.02 +/- 1.4 cm, and -0.41 +/- 1.15 cm(2), and the ICCs were 0.85, 0.79, and 0.75.


CONCLUSIONS
Assessment of cervical dilatation using 3D ultrasonography during labor is feasible and reproducible.
Zimerman
Ariel L
AL
Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, affiliated with the Sackler School of Medicine, Tel-Aviv University, Zerifin, Israel. zimermanariel@hotmail.com
Smolin
Ana
A
Maymon
Ron
R
Weinraub
Zvi
Z
Herman
Arie
A
Tobvin
Yosef
Y
D000328:Adult; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007747:Labor Stage, First; D015588:Observer Variation; D010808:Physical Examination / Q000379:methods*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013223:Statistics as Topic; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult