The correlation between transperineal sonography and digital examination in the evaluation of the third-trimester cervix

Abstract

To determine the correlation between transperineal or translabial ultrasound and digital examination of the cervix in the third trimester in women presenting to the obstetrical triage area complaining of uterine contractions and/or rupture of membranes. One hundred women were evaluated initially with an ultrasound unit using a 5-MHz glove-covered curvilinear transducer applied to the perineum in the sagittal plane. Immediately after the ultrasound evaluation, another examiner assessed the cervix digitally, blinded to the sonographic results. Cervical dilatation, length, and station were assessed. Transperineal ultrasound correlated (P < .001) with digital cervical examination in the assessment of dilatation (Pearson correlation coefficient 0.87), length (Pearson correlation coefficient 0.80), and corrected station (Pearson correlation coefficient 0.69). There is a statistically significant correlation between the digital cervical examination and the sonographic assessment of cervical dilatation, length, and station by the transperineal approach.