Cervical pessary for preventing preterm birth in singletons and twin pregnancies: an update systematic review and meta-analysis

To evaluate the effectiveness of cervical pessary in preventing preterm birth (PTB) and improving perinatal outcomes among singleton and twin pregnancies. Electronic databases were systematically searched from their inception until 14 March 2019. Randomized clinical trials comparing the effectiveness of cervical pessary placement with expectant management were included. The primary outcome was the incidence of PTB Thirteen studies were included, involving eight studies about singleton and six studies about twin pregnancies. For singleton pregnancies with short cervical length, cervical pessary, comparing with expectant treatment, seemed have no effectiveness in preventing PTB Comparing with the expectant treatment, the effectiveness of cervical pessary for reducing the risk of PTB remains uncertain. Additional trials are warranted to further evaluate the effectiveness of cervical pessary.