Diagnostic accuracy of D-dimer for predicting postpartum venous thromboembolism: a systematic review and meta-analysis

BACKGROUND: Postpartum women are at increased risk of venous thromboembolism (VTE). Existing risk scores, such as RCOG and Caprini, rely on clinical factors alone and may lack accuracy. D-dimer, a widely used biomarker for VTE in non-pregnant populations, may improve postpartum risk prediction, but evidence remains inconsistent. METHODS: A systematic search of PubMed, Embase, Web of Science, Cochrane Library, and CBM was performed through July 31, 2025. Studies assessing D-dimer alone for postpartum VTE were included. Data were extracted to construct 2 × 2 tables, and pooled estimates were calculated using a bivariate random-effects model. RESULTS: Six studies (14,024 women; 193 VTE cases), all from mainland China, were included. D-dimer cut-offs varied widely (0.56–5.55 mg/L). The pooled sensitivity was 0.82 (95% CI: 0.63–0.93) and specificity was 0.69 (95% CI: 0.42–0.87). The pooled PLR was 2.61, NLR 0.26, and DOR 10.00. The SROC curve yielded an AUC of 0.84, indicating moderate diagnostic accuracy. Leave-one-out analysis confirmed robustness. CONCLUSION: D-dimer shows moderate accuracy for predicting postpartum VTE and may be useful as an adjunct to clinical models, especially in resource-limited settings. However, heterogeneous cut-offs and restriction to Chinese populations limit generalizability. Larger multicenter studies are needed.