Cervical pessary for preventing preterm birth: a meta-analysis

To evaluate the efficacy of cervical pessary in the prevention of preterm birth and its influence on pregnancy and maternal outcomes, so as to provide a clinical basis for cervical pessary to prevent premature delivery.

The databases of PubMed, Web of Science, CNKI, WanFang Data, etc, were used to search for the eligible articles. The relevant data were abstracted by two independent reviewers and performed with Stata 12.0.

Pregnancy Result: the PTB rates of pessary and control group before 28, 32, 34, and 37 weeks were analyzed and the combined RR (95%CI) values were 0.78 (0.46, 1.31), 0.92 (0.67, 1.28), 0.74 (0.49, 1.13), and 0.79 (0.54, 1.15). Compared with the control group, the utilization rate of tocolytic and corticosteroids was decreased 21% (RR = 0.79, 95%CI = 0.66-0.94) and 18% (RR = 0.82, 95%CI = 0.70-0.96). The risk of PROM and the difference was not statistically significant (p > .05). Subgroup analysis showed that there was no significant difference on the PTB rate subgroup and twins subgroup during 28 and 34 weeks (p > .05). The results showed that there was no significant difference on neonatal weight <1500 g and <2500 g (p > .05). Three articles on the average gestational age were included in the cervical length <25 mm. The deepen analysis on the relationship between gestational weeks and neonatal showed that: the risk of neonatal sepsis was reduced by 55% (RR = 0.45, 95% = 0.22 - 0.93); RDS and intraventricular hemorrhage are no significant difference on pessary and control group. The neonatal results were analyzed by subgroup analysis of singletons and twins, and there was no significant difference between two groups (p > .05).

Compared with expectant management, pessary could prolong pregnancy and reduce the rate of tocolysis and corticosteroids. More registered trials are ongoing which may substantially change our results.