Cervical pessaries have been used for 50 years to prevent preterm birth. All previous studies showing the effectiveness of this device as a preventive strategy for patients at risk of preterm birth were nonrandomized (mostly retrospective or case-control).
This prospective, open-label, randomized trial was designed to determine whether the use of a cervical pessary in women with a short cervix previously identified during routine midgestational transvaginal scanning reduced the early preterm delivery rate. The Pesario Cervical para Evitar Prematuridad (PECEP) trial was conducted between 2007 and 2010 at 5 hospitals in Spain. All participants were pregnant women (aged 18–43 years) undergoing routine second trimester ultrasonography at 18 to 22 weeks of gestation who had a cervical length of 25 mm or less. Blinding was not possible because of the nature of the intervention. Multivariate analysis was performed with logistic regression. Analysis was according to the intention-to-treat principle.
Among 385 pregnant women with a short cervix, 192 were randomized to the pessary group and 193 to the expectant management group; 190 in each group were included in the final analysis. The primary study outcome—spontaneous delivery before 34 weeks of gestation—occurred significantly less frequently in the pessary group compared with the expectant management group: 12 (6%) versus 51 (27%); the odds ratio was 0.18, with a 95% confidence interval of 0.08 to 0.37 (P < 0.0001). There were no serious adverse events in the pessary group.
These findings demonstrate that a cervical pessary is safe and effective for prevention of preterm birth in a population of appropriately selected at-risk pregnant women with a short cervix that had been identified at the midtrimester scan.