Objective:This study aims to investigate the risk factors of preterm twin pregnancy and establishment of predictive model. Methods:Twin pregnant women delivered in the Affiliated Obstetrics and Gynaecology Hospital of Nanjing Medical University from January 2017 to December 2019 were analyzed retrospectively,who were divided into preterm group(<37 weeks)and term group(≥37 weeks)according to the gestational week of delivery. Univariate analysis was used to analyze the general conditions,pregnancy complications of the two groups. Multivariate logistic regression analysis was used to analyze the independent risk factors of preterm in twin pregnancy. ROC curve was used to evaluate the predictive value. Results:A total of 1 783 pregnant women with twin pregnancy,856 in the preterm group,and 927 in the term group were collected,the incidence of preterm birth was 48%. Causes of preterm labor in the twin pregnancy were listed at below:iatrogenic preterm labor accounted for 43%,premature rupture of membranes accounted for 29%,and spontaneous preterm labor accounted for 28%. Irregular prenatal examination,monochorionic twins,discordant twins,cicatrical ulerus,premature rupture of membranes,hypertension in pregnancy,abnormal amniotic fluid,intrahepatic cholestasis,intrauterine distress,and chorioamnionitis in the preterm group were higher than those in the control group,and the differences were statistically significant(P < 0.05). Multivariate logistic regression analysis showed that discordant twins,irregular prenatal examination,monochorionic twins,intrahepatic cholestasis,abnormal amniotic fluid,hypertensive disorder complicating pregnancy, premature rupture of membranes,intrauterine distress,chorioamnionitis and cicatrical ulerus were the independent risk factors of preterm twin pregnancy. The ROC curve verified the high predictive efficiency of the model. Conclusion:The occurrence of preterm birth in twin pregnancy is related to a variety of maternal and fetal risk factors. The incidence of preterm twin pregnancy is fairly high and could be predicted from the risk factors.