Cerclage is associated with the increased risk of preterm birth in women who had cervical conization

Background: The aim of this study was to determine the effect of cerclage in women who underwent cervical conization. Methods: Study data were collected from the Korea National Health Insurance Claims Database of the Health Insurance Review and Assessment Service for 2009-2013. Women who had a conization in 2009 and a subsequent first delivery between 2009 and 2013 in Korea were enrolled. Results: Among the women who had conization in 2009, 1075 women had their first delivery between 2009 and 2013. A cerclage was placed in 161 of the women who were treated by conization. The rate of preterm birth was higher in the women who were treated with cerclage following a conization compared with those without cerclage (10.56 vs 4.27, p<0.01, respectively). The multivariate regression analysis revealed that the women who were treated cerclage following a conization had an increased risk of preterm delivery compared with women without cerclage (odds ratio (OR), 2.6, 95% confidence interval (CI), 1.4-4.9). Conclusion: Our study showed that cerclage associated with an increased risk of preterm birth and preterm premature rupture of membranes in women who underwent conization. Further studies are required to clarify the mechanism by which cerclage affects the risk of preterm birth.