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

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.