목적: To compare the efficacy of progesterone versus cervical cerclage in preventing preterm birth in twin pregnancies with a history of preterm birth or presentation of a short cervix 방법: This was a retrospective study of twin pregnancies managed at Obstetrics and Gynecology, CHA Bundang Medical center from December 2007 to April 2016 using medical records. We included 432 patients with 28weeks of gestation or less who were diagnosed with a cervical length less than 25 mm or who had history of preterm birth. The study population were devided 4 groups including progesterone group (n=138), cervical cerclage group (n=21), progesterone with cerclage group (n=78) and conservative treatment group (n=195) and outcomes were compared among 4 groups. The primary outcome measures were spontaneous birth at <28, 32, 34, or 36 weeks of gestation. The secondary outcome measures included hospitalization for tocolytics, antenatal corticosteroids and small for gestational age. 결과: Incidence of spontaneous delivery at <34 weeks of gestation was 26.9% (21/78) and 13.8% (27/195) in the progesterone with cerclage group and conservative treatment group, respectively (OR 36.9, 95% CI 5.45-250.24, p<0.001). There was statistically significant differences received antenatal corticosteroid between two groups. (OR 4.39, 95% CI 1.29-14.98, p=0.018) 결론: In twin pregnancies where patients are diagnosed with short cervical length or with a prior preterm birth history, treatment of cervical cerclage with progesterone showed significantly greater occurrence of delivery before 34 weeks compared to conservative management.