Vaginal ultrasound as an adjunct to cervical digital examination in women at risk of early delivery

Abstract

Aim: To study the utility of transvaginal ultrasound (TVU) in women at high risk of preterm delivery.

Methods: Women who were scheduled for frequent digital examinations of the cervix from 16 to 26 weeks of gestation had TVU determinations of cervical length before their clinical examinations. Clinicians were blinded to the TVU results. Therefore, clinical decision-making was independent of the unreported TVU data. The plan was to relate the ultrasound characterization of the cervix to the study's primary endpoint, the need for hospitalization prior to 26 weeks of gestation for: preterm premature rupture of membranes, preterm labor, cerclage placement, or delivery.

Results: Seventeen subjects completed the study. All 3 who met the primary endpoint had ultrasound cervical lengths <20 mm on earlier prenatal visits, when digital examinations of the cervix did not detect problems. A 4th woman had ultrasound lengths <20 mm (she delivered at 27(6)/(7) weeks).

Conclusion: TVU determination of cervical length provides an earlier warning of cervical shortening than does digital examination.