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

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)623.e1-6
Number of pages6
JournalAmerican Journal of Obstetrics and Gynecology
Issue number6
Publication statusPublished - Jun 2009

King's Authors


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.

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).

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

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