Cervical pessary in the prevention of preterm births in multiple pregnancies with a short cervix: PRISMA compliant systematic review and meta-analysis

<b>Background:</b> Preterm births occur frequently in multiple pregnancies with a short cervix. The cervical pessary is a potential intervention for prevention of preterm births. <b>Objective:</b> To assess the effectiveness of cervical pessary in the prevention of preterm births in multiple pregnancies with a short cervix (&lt;25 mm). <b>Search strategy:</b> Major databases from 2006 to 20th November 2016 were searched for relevant terms. <b>Selection criteria:</b> We included randomized controlled trials that assessed the effectiveness of cervical pessary on pregnancy outcomes in multiple pregnancies with a short cervix. <b>Data collection and analysis:</b> Risk ratio was used as the summary measure with random effects model. We assessed heterogeneity between studies using the I² index. Quality assessment was done based on Cochrane Handbook Method. <b>Main results:</b> Pooled data showed no benefit of using cervical pessary in the prevention of preterm births, birth weights less than 1500 g, less than 2500 g, adverse neonatal events and fetal/neonatal deaths in twin pregnancies with a short cervix. <b>Conclusion:</b> We are unable to show benefit of using cervical pessary in preventing preterm births in twin pregnancies with a short cervix. However, as cervical pessary is a reasonable intervention, there is a need for more randomized controlled trials in this area.