Purpose: The aim of this study was to analyze how obstetricians use risk factors for high-risk pregnancies to predict complicated pregnancies.Methods: Twenty-four obstetricians were surveyed using a questionnaire that included 75 high-risk pregnancy factors identified by the Korean Society of Obstetrics and Gynecology. These factors are used to predict 11 types of complicated pregnancies: preterm labor, preterm premature rupture of membranes, incompetent internal os of the cervix, placenta previa, placenta abruptio, postpartum hemorrhage, preeclampsia/eclampsia, oligohydramnios, polyhydramnios, gestational diabetes mellitus, and intrauterine growth restriction.Results: Obstetricians utilized 65 of the 75 identified high-risk factors to predict 11 types of pregnancy complications. They identified twin pregnancy as the most significant risk factor, followed by chronic hypertension, a history of preterm birth, pregestational diabetes mellitus, advanced maternal age over 40, and a history of preeclampsia and eclampsia. Twin pregnancies were associated with all 11 complicated pregnancies. Ten of the 75 risk factors were not used for predicting complications.Conclusion: This study demonstrated that obstetricians recognized twin pregnancy as a strong risk factor associated with complications of pregnancy. Based on the results of this paper, we expect prediction models for complicated pregnancies to be developed in the future.