Double versus single cervical cerclage for the prevention of preterm births

Objective: To evaluate the effectiveness double cervical cerclage in reducing antenatal complications and improve perinatal outcomes. Methods: We searched Medline, Scopus, Clinicaltrials.org, The Cochrane Central Register of Controlled Trials and Google Scholar search engines. Results: Six studies were included that involved 880 women. Double cerclage was significantly superior to single cerclage in reducing preterm births <34 weeks (734 cases, OR 0.59, 95% CI 0.40, 0.86) and preterm births <28 weeks (645 cases, OR 0.43, 95% CI 0.26-0.73). It also significantly increased the gestational age (380 cases, MD 2.63, 95% CI 0.87, 4.39). However, as a technique, it failed to improve the rates of preterm births <37 weeks (740 cases, OR 0.98, 95% CI 0.72, 1.34) the incidence of chorioamnionitis (740 cases, OR 0.83, 95% CI 0.51, 1.36) and the occurrence of preterm premature rupture of the membranes (796 cases, OR 1.32, 95% CI 0.95, 1.82). Conclusions: It seems that double cerclage effectively increases the gestational age at delivery and decreases the rates of extremely premature births. However, as a procedure, it does not reduce the incidence of antenatal morbidity or the neonatal death rates. Further research is needed in the field as our meta-analysis is limited by the small number of enrolled studies.