Development and Temporal Validation of a Thromboelastography-Based Nomogram for Queensland-Defined High Thrombotic Risk in Postpartum Women

This study developed and temporally validated a nomogram that integrates thromboelastography (TEG) and maternal clinical factors to identify women classified as having high thrombotic risk according to the 2020 Queensland Clinical Guideline at postpartum reassessment after 24 h. The derivation cohort included 447 women who delivered at Foshan Women and Children Hospital between January 1, 2021, and December 27, 2022; 346 had Queensland scores of 0-2 and 101 had scores of ≥3. A same-center temporal validation cohort included 207 women who delivered between December 28, 2022, and February 14, 2025. Candidate clinical and TEG variables were evaluated using multivariable logistic regression, and model performance was assessed using receiver operating characteristic analysis, calibration, and decision curve analysis. The final model retained hypertensive disorders of pregnancy, maternal age, current body mass index, native-cup TEG reaction time (R), and 24-h postpartum blood loss. Discrimination was acceptable in the derivation cohort (area under the curve [AUC], 0.791; 95% confidence interval [CI], 0.737-0.845; sensitivity, 70.3%; specificity, 77.2%) and good in the temporal validation cohort (AUC, 0.847; 95% CI, 0.771-0.923; sensitivity, 75.8%; specificity, 85.6%). The model estimates Queensland-defined high thrombotic risk rather than objectively confirmed venous thromboembolism. It may support simplified postpartum reassessment after the first 24 h, but multicenter validation against objectively confirmed thrombotic outcomes is required before claims regarding event prediction or clinical implementation can be made.