Randomized trial of ultrasound-indicated cerclage in singleton women without lower genital tract inflammation

This is the first report of a randomized trial of cerclage on pure cervical shortening without vaginosis or cervicitis. The objective of our multicenter randomized controlled trial was to assess the benefits of ultrasound-indicated cervical cerclage in the mid-trimester to prevent preterm birth in women who have no signs of infection or inflammation of the lower genital tract.

Women with a short cervical length < 25 mm between 16 and 26 weeks of gestation were randomly assigned to receive a Shirodkar cerclage, McDonald cerclage, or bedrest (no cerclage). Before being randomly assigned to one of the three groups, all women were screened for infection/inflammation of the lower genital tract; those with positive results were excluded from the study. The ratio of preterm delivery as a primary end-point was evaluated in the groups.

A total of 106 singleton patients with a short cervical length were assessed for study eligibility; 106 patients were randomized to the three treatment options. Ultimately, 98 patients (in the Shirodkar [n = 34], McDonald [n = 34] and bedrest [n = 30] groups) were analyzed. No differences in preterm delivery or perinatal outcomes were found between the three groups. Significantly fewer patients in the Shirodkar group required hospitalization for treatment of threatened preterm labor when compared to patients in the bedrest group.

For women with a short cervical length < 25 mm between 16 and 26 weeks of gestation, Shirodkar cerclage might be considered to reduce the occurrence of threatened preterm labor.