Double versus single cervical cerclage for the prevention of preterm births

To evaluate the effectiveness double cervical cerclage in reducing antenatal complications and improve perinatal outcomes.

We searched Medline, Scopus, Clinicaltrials.org, The Cochrane Central Register of Controlled Trials and Google Scholar search engines.

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).

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.