title: Can transabdominal ultrasound identify women at high risk for short cervical length?
abstract: OBJECTIVE
  To determine whether transabdominal cervical length screening could identify women at high risk for having a short cervix on transvaginal ultrasound.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
authors.affiliation: Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Hospital of University of Pennsylvania, Philadelphia, PA 19104, USA. alexander.friedman@gmail.com
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Friedman
authors.forename: Nadav
authors.initials: N
authors.lastname: Schwartz
authors.forename: Jack
authors.initials: J
authors.lastname: Ludmir
authors.forename: Samuel
authors.initials: S
authors.lastname: Parry
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Bastek
authors.forename: Harish M
authors.initials: HM
authors.lastname: Sehdev
mesh_terms: D000328:Adult; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods*