Can transabdominal ultrasound identify women at high risk for short cervical length?. (17th April 2013) - Friedman, Alexander M.
Abstract Objective To determine whether transabdominal cervical length screening could identify women at high risk for having a short cervix on transvaginal ultrasound. Design Retrospective cohort study. Setting Tertiary referral center. Population A total of 703 patients with a singleton pregnancy at 18 to 23+6 weeks of gestation who underwent transabdominal and transvaginal cervical length assessment during anatomy ultrasound at a single institution between January 2007 and October 2011. Methods Electronic medical records were reviewed to identify women who met the study criteria. Main outcome measures The primary outcome was the number of women with a short transabdominal cervical length (defined as ≤30 mm) who needed to undergo transvaginal ultrasound to detect one woman with a short transvaginal cervical length of ≤20 mm. Results In all, 703 patients were included in the primary analysis; 3.42 women with transabdominal cervical length ≤30 mm needed to undergo transvaginal ultrasound to detect one woman with transvaginal ultrasound cervical length ≤20 mm. Of women with short transvaginal cervical length ≤20 mm, 89.8% had a transabdominal measurement ≤30 mm and 96.7% had a transabdominal measurement ≤33 mm. Conclusions Screening of transabdominal cervical length may represent a useful strategy for detecting women with short cervix on transvaginal ultrasound.