Cervical length < or = 25 mm in low-risk women: a case control study of cerclage with rest vs rest alone.

Abstract

The purpose of this study was to evaluate the clinical utility of cerclage in low risk women with cervical length (CL) < or = 25 mm at transvaginal ultrasound (TVU). This was a retrospective cohort study of women with CL < or = 25 mm identified incidentally at TVU examinations between 16(0/7) to 24(6/7) weeks, with no history of previous preterm birth or midtrimester losses. The primary study outcome was rate of preterm delivery < 35 weeks' gestation. Women undergoing cerclage placement (n = 31) had shorter CL (P < .001) and lower gestational age at presentation (P < .001) than those managed with rest alone (n = 36). Gestational age at delivery was 37.6 +/- 3.6 vs 38.5 +/- 2.1 weeks (P = .17), and delivery at < 35 weeks occurred in 5/31 versus 2/36 cases, respectively (P = .23). The lack of a significant association between cerclage and rate of delivery < 35 weeks persisted after controlling for gestational age at TVU and initial CL (P = .81). Cerclage placement does not improve pregnancy outcome in low-risk women with incidental detection of CL < or = 25 mm in the early second trimester.