目的 探讨臀位外倒转术成功的相关影响因素，并构建列线图模型并验证预测效能。方法 分析2018年4月至2022年10月于厦门市妇幼保健院行臀位外倒转术230例孕妇临床资料，其中165例成功，65例失败。按照7∶3比例分为训练集与验证集。收集研究对象的临床资料及术前超声指标，logistic回归分析臀位外倒转术成功的影响因素，进一步经R 4.2.3软件建立列线图模型。运用C-指数、标准校准曲线评估模型效能，决策曲线评估模型的临床实用性。结果 logistic回归分析结果显示，单臀先露、前壁胎盘、羊水指数<14.10cm、初产妇是影响臀位外倒转术成功的危险因素[比值比（OR）值分别为0.173、0.170、1.335和1.975，P<0.05]。基于上述影响因素构建列线图模型。训练集C-指数为0.838（95%CI 0.775~0.900），受试者工作特征曲线（ROC）曲线下面积为0.815；验证集C-指数为0.822（95%CI 0.759~0.884），ROC曲线下面积为0.780。模型曲线与理想曲线较为接近，与极端曲线分离。结论 基于胎盘位置、臀先露类型、羊水指数、产次等因素构建列线图预测模型，其效能较高，有良好的临床实用性，可作为臀位外倒转术适用人群的筛选及评估工具。

Objective To analyse the influencing factors related to the success of external cephalic version，and to construct a line chart model and verify the predictive efficacy. Methods A retrospective cohort study was conducted which included 230 pregnant women who underwent external cephalic version at Women and Children's Hospital Affiliated to Xiamen University from April 2018 to October 2022，of which 165 cases were successful and 65 failed. The cases were divided into training set and validation set according to the ratio of 7∶3. The clinical data and preoperative ultrasound indexes of the study subjects were collected，and the influencing factors of the success of external cephalic version were analysed by logistic regression. The line chart model was then established by R 4.2.3 software. The C-index and standard calibration curve were used to assess the efficacy of the model，and the decision curve was used to assess the clinical practicality of the model. Results Logistic regression analysis showed that frank breech，anterior placenta，amniotic fluid index <14.10 cm，and primiparity were the risk factors for the success of external cephalic version [odds ratio （OR） values being 0.173，0.170，1.335，and 1.975，P<0.05]. A line chart model was constructed based on the above influencing factors. The C-index of the training set was 0.838（95%CI 0.775-0.900），and the area under the ROC curve was 0.815；the C-index of the validation set was 0.822（95%CI 0.759-0.884） and the area under the ROC curve was 0.780. The model curves were closer to the ideal curves，and separated from the extreme curves. Conclusion The line chart prediction model based on placental position，breech presentation type，amniotic fluid index，and the number of deliveries has high efficacy and good clinical practicality，and it can be used as a tool for screening and assessing the population fit for external cephalic version.