Effectiveness of a cervical pessary in prolongation of pregnancy after an arrested episode of preterm labor: a systematic review and individual patient data meta-analysis.

Background: Randomized controlled Trials (RCTs) show conflicting results on the effectiveness of a cervical pessary after an arrested episode of preterm labor (PTL) aiming to prolong pregnancy.

Objective: To assess the effectiveness of a cervical pessary in prolongation of pregnancy after an arrested episode of PTL by utilizing individual participant data (IPD) meta-analysis.

Data Sources: Databases Central, Embase, Medline, and clinical trial databases (ClinicalTrials.gov, ISRCTN, EU-CTR) were searched from inception until January 2024.

Study Eligibility Criteria: Randomized controlled trials investigating individuals between 24 and 34 weeks of gestation with an arrested episode of PTL and who were subsequently randomized to cervical pessary or no intervention.

Study Appraisal And Synthesis Methods: Studies were assessed for data integrity and risk of bias. Main outcomes were prolongation of pregnancy >7 days, interval between randomization and delivery, and a composite of adverse neonatal outcome. A one-step meta-analysis approach was employed, and the intention-to-treat principle was applied.

Results: Four RCTs had IPD available. In singleton pregnancies (total N=546; 275 individuals in the pessary group, 271 individuals in the control group), pessary placement did not decrease delivery risk within 7 days (relative risks [RR] 0.87; 95% confidence intervals [CI] 0.40-1.9), prolong pregnancy (mean differences 4.5 days; 95% CI -0.08 to 9.0), nor reduce the risk of adverse neonatal outcomes (RR 0.95; 95% CI 0.53-1.7). The incidence of readmissions for a new episode of PTL was significantly less frequent in the cervical pessary group (RR 0.66, 95% CI 0.50-0.85). Two studies investigating multiple pregnancies (N=167, 84 individuals in the pessary group, 83 individuals in the control group) were identified, showing contradictory results that could not be explained by study differences. Therefore, merging IPD and pooling of was uninformative.

Conclusion: In individuals with a singleton pregnancy with an episode of PTL between 24 and 34 weeks of gestational age, pessary placement does not prevent delivery within 7 days, preterm birth, or neonatal outcomes. A pessary might reduce the probability of readmissions for PTL. El resumen está disponible en Español al final del artículo.