ACR Appropriateness Criteria® Assessment of Gravid Cervix.

Preterm birth remains the leading cause of perinatal morbidity and mortality. Although the greatest risk factor for preterm birth is a history of prior preterm birth, a short cervical length (≤25 mm) before 24 weeks' gestational age is also associated with increased risk of spontaneous preterm delivery. As such, cervical length assessment has become of particular interest in predicting those patients at risk for preterm birth. Other clinical scenarios (eg, preterm labor, induction of labor, and active labor) may arise, in which assessment of the cervix may be of interest. Ultrasound is the mainstay imaging modality for assessing the gravid cervix, with transvaginal ultrasound recommended in patients at high risk for preterm birth or suspected preterm labor. Transperineal ultrasound is an alternate approach in those cases where transvaginal ultrasound in contraindicated. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.