ObjectiveTo analyze the influencing factors for occurrence of perinatal deep vein thrombosis (DVT) in pregnant women, and to establish a risk prediction model of occurrence of perinatal DVT in pregnant women based on serological markers. MethodsThe clinical data of 194 pregnant women were retrospectively analyzed, and they were randomly divided into training set (143 cases) or test set (51 cases). According to the presence of DVT occurred during perinatal period, pregnant women in the training set were divided into occurrence group (n=45) or non-occurrence group (n=98). The clinical data and laboratory indicators were compared between pregnant women of the two groups. The influencing factors for occurrence of perinatal DVT were analyzed by employing the Logistic regression model. Based on the influencing factors, a nomogram prediction model was established. The test set was used for external validation, the consistency index was calculated, the calibration curve was drawn to evaluate predictive efficiency of the nomogram prediction model, and the decision curve was drawn to evaluate the clinical application effect of the nomogram prediction model. ResultsThe occurrence group exhibited an older age, a higher incidence rate of pregnancy-accompanied diseases, and higher levels of D-dimer and homocysteine (Hcy), while a lower level of 25-hydroxyvitamin D (25-[OH]D) as compared with the non-occurrence group (P<0.05). The results of multivariate Logistic regression model revealed that age, D-dimer level, Hcy level, and pregnancy-accompanied diseases were the risk factors for occurrence of perinatal DVT in pregnant women, and 25-(OH)D level was its protective factor (P<0.05). The nomogram prediction model established based on the aforementioned influencing factors exerted favorable consistency and discrimination. The results of decision curve analysis indicated that when the prediction probability was 0-0.59, more clinical benefits could be obtained by using this model for predicting occurence of perinatal DVT in pregnant women. ConclusionAge, D-dimer level, Hcy level, and pregnancy-accompanied diseases are the risk factors for occurrence of perinatal DVT in pregnant women, and 25-(OH)D level is its protective factor. The nomogram prediction model established based on the aforesaid influencing factors exerts favorable predictive efficiency and clinical application value to a certain extent.