The Effect of Cervical Pessary on Increasing Gestational Age at Delivery in Twin Pregnancies with Asymptomatic Short Cervix: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background The incidence of preterm delivery is much higher in twin pregnancies compared to singletons, and even higher if a short cervical length is detected in the second trimester. Studies are contradictory regarding the efficacy of a cervical pessary to decrease preterm birth in twin pregnancies and short cervical length. Objectives To conduct a systematic review and meta-analysis investigating the efficacy of cervical pessary in prolonging gestation, preventing preterm birth, and reducing adverse neonatal outcomes in twin pregnancies with an asymptomatic short cervix. Data sources PubMed, Scopus, Web of Science, and ClinicalTrials.org were searched for randomized controlled trials (RCTs) from inception to June 2023. Study eligibility criteria In this study, RCTs comparing the cervical pessary to expectant management in the pregnant population with twin gestations, and asymptomatic short cervix, were included. Study appraisal and synthesis methods The Cochrane risk-of-bias-2 tool for RCTs (ROB-2) was used for evaluation of the risk of bias in included studies. A meta-analysis was performed by calculating risk ratio (RR) and mean difference (MD) with their 95% confidence interval (95% CI) using the random effects model or fixed effect model based on heterogeneity and accounting for potential covariates among the included RCTs. Results A total of six RCTs were included in the analysis. Cervical pessary did not significantly increase the gestational age at delivery in twin pregnancies with asymptomatic patients (MD: 0.36 weeks [-0.27, 0.99]; P-value: 0.270, I2: 72). Moreover, the cervical pessary use did not result in a reduction of spontaneous or all preterm birth before to 37 weeks of gestation (RR: 0.88 [0.77, 1.00], P-value: 0.061, I2: 0.0%). There was no statistically significant difference in the composite neonatal adverse outcomes (RR: 1.001 [0.86, 1.16], P-value: 0.981, I2: 20.9%), including early respiratory morbidity, intraventricular hemorrhage, necrotizing enterocolitis, and confirmed sepsis. Conclusion The use of cervical pessary in twin pregnancies with asymptomatic short cervix does not appear to be effective in increasing the gestational age at delivery, preventing preterm birth, or reducing adverse neonatal outcomes. This indicates that alternative interventions should be sought for the management of this patient population.