Cervical pessaries for the prevention of preterm birth: a systematic review and meta-analysis

The objective of this study is to evaluate the effectiveness and safety of cervical pessaries for the prevention of preterm birth.

We searched PubMed, Embase, Web of Science, and other sources from inception to July 2016. This analysis referred to pregnant women with singleton/multiple viable fetus/fetuses, with or without cervical pessary placement.

Six randomized control trials and five cohort studies involving 3911 participants were included. Overall, cervical pessary placement was slightly associated with the decrease of spontaneous delivery less than 34 weeks (relative risk 0.65 [95% CI: 0.44-0.96]) and increased gestational age at delivery (weighted mean difference 1.03 weeks [95% CI: 0.37-1.70]) in multiple pregnancies, but not with poor perinatal outcomes. Pessary placement in singleton pregnancies did not show any difference. A planned subgroup analysis showed multiple pregnancies with shorter cervical length (≤25 mm) had a longer prolongation of pregnancy (weighted mean difference 2.08 weeks [95% CI: 1.35-2.82]).

This meta-analysis suggested pessary placement could slightly reduce the rate of spontaneous preterm delivery before 34 weeks, and increase gestational age at delivery in multiple pregnancies, but not in singleton pregnancies. More studies of high quality with detailed records are urgent to confirm the efficacy of this procedure.