Cervical pessary in singleton gestations with arrested preterm labor: a randomized clinical trial

Background: Cervical pessary has been proven to be effective in reducing the rate of preterm birth in asymptomatic women with singleton gestations and short cervical length in the midtrimester of pregnancy; however, the efficacy of this device in women with arrested preterm labor is still a subject of debate.

Objective: This study aimed to test the hypothesis that the use of a cervical pessary in women with singleton pregnancy and arrested preterm labor would reduce the risk of preterm birth at <37 weeks of gestation.

Study design: This study is a parallel group, nonblinded, randomized trial. Participants included in the study were women with a diagnosis of arrested preterm labor between 24 0/7 and 33 6/7 weeks of gestations. The participants were randomized to either the cervical pessary group or no pessary group in a 1:1 ratio. The primary endpoint was preterm birth at <37 weeks of gestation. A sample size of 120 participants was determined, but the trial was concluded before the completion of enrollment.

Results: A total of 61 women with singleton pregnancies and arrested preterm labor at 24 0/7 to 33 6/7 weeks of gestation were enrolled in the trial. Of the 61 women, 32 were randomized to the cervical pessary group and 29 to the control group. Preterm birth at <37 weeks of gestation occurred in 14 women (43.8%) in the pessary group and 6 women (20.7%) in the control group (relative risk, 2.98; 95% confidence interval, 0.96-9.30).

Conclusion: In this underpowered trial, among women with singleton pregnancies and arrested preterm labor, compared with no pessary use, the use of a cervical pessary does not result in a lower rate of preterm birth at <37 weeks of gestation.