Cervical insufficiency (CI), responsible for 8% of preterm births (PB), is used to describe painless cervical dilation leading to recurrent second-trimester pregnancy losses/births of otherwise normal pregnancies. Structural weakness of cervical tissue was thought to cause or contribute to these adverse outcomes. The term has also been applied to women with one or two such losses/births or at risk for second-trimester pregnancy loss/birth. Cervical pessary and cervical cerclage are both considered as preventive treatments in women at risk for PB. This study aims to demonstrate that the cervical pessary could reduce the preterm birth rate before 37 weeks of gestation in women with prior PB due to cervical insufficiency or in women with prior PB and a short cervix in the current pregnancy.

Methods/Design: This is an open-label, pilot, multicentre, prospective, randomised controlled trial (RCT). Enrolees are women with singleton pregnancies and previous PB based on CI (primary intervention, <16 weeks) or in case of previous PB and a short cervical length in current pregnancy ≤ 25 mm (secondary intervention, <24 weeks). Women are randomised (1:1) either to cervical cerclage or pessary treatment. The primary outcome is the spontaneous preterm birth rate before 34 weeks of gestation. The sample size was calculated, as a pilot study, based on the estimated population that we will be able to recruit during the duration of the trial: 60 women, 30 for each group (cervical cerclage and cervical pessary group) to observe, at least a reduction in the PB rate < 34 weeks from 34% to 27% in the pessary group, as does cerclage.

Discussion: The outcome of this study will show the effectiveness of a cervical cerclage and of a cervical pessary in this group of patients.

Inclusion Criteria:

• Singleton pregnancy
• Minimum age: 18 years
• Previous PB based on CI (primary intervention, <16 weeks) or in case of previous PB and a short cervical length in current pregnancy ≤ 25 mm (secondary intervention, <24 weeks). Women are randomised (1:1) either to cervical cerclage or pessary treatment.

Exclusion Criteria:

• Major fetal abnormalities (requiring surgery or leading to infant death or severe handicap)
• Threatened preterm labour at time of randomization
• Spontaneous rupture of membranes at time of randomization
• Chorioamnionitis at time of randomization
• Active vaginal bleeding
• Placenta previa