A randomized controlled trial of cervical scanning vs history to determine cerclage in women at high risk of preterm birth (CIRCLE trial)

Am J Obstet Gynecol. 2009 Jun;200(6):623.e1-6. doi: 10.1016/j.ajog.2009.03.010. Epub 2009 Apr 19.


Objective: We sought to compare history-indicated placement of cervical cerclage based on history- vs ultrasound-indicated placement in women at risk of preterm birth.

Study design: We conducted a randomized controlled trial of history-indicated cervical cerclage suture based on history (clinician preference) vs ultrasound (< 20 mm cervical length) indicated in women at increased risk.

Results: The incidence of the primary outcome, preterm delivery between 24(+0) and 33(+6) weeks, was similar: 19/125 (15%) in the history-indicated group vs 18/122 (15%) in the ultrasound-indicated group (relative risk [RR], 0.97; 95% confidence interval [CI], 0.54-1.76). Those women randomized to the ultrasound-indicated arm were significantly more likely to receive a cerclage (32% vs 19%; RR, 1.66; 95% CI, 1.07-2.47) and progesterone (39% vs 25%; RR, 1.55; 95% CI, 1.06-2.25).

Conclusion: Screening women at high risk with cervical ultrasound to determine cerclage placement results in more intervention but similar outcome compared with history-indicated placement.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Habitual
  • Adult
  • Cerclage, Cervical*
  • Cervix Uteri / diagnostic imaging*
  • Female
  • Humans
  • Pregnancy
  • Premature Birth / prevention & control*
  • Risk Factors
  • Ultrasonography