D‐dimer to rule out venous thromboembolism during pregnancy: A systematic review and meta‐analysis

BACKGROUND: The usefulness of D‐dimer measurement to rule out venous thromboembolism (VTE) during pregnancy is debated. OBJECTIVES: We performed a systematic review and meta‐analysis to investigate the safety of D‐dimer to rule out acute VTE in pregnant women with suspected pulmonary embolism and/or deep vein thrombosis. METHODS: Two reviewers independently identified studies through PubMed and Embase until June 2021, week 1. We supplemented our search by manually reviewing reference lists of all retrieved articles, clinicalTrials.gov, and reference literature. Prospective or retrospective studies in which a formal diagnostic algorithm was used to evaluate the ability of D‐dimer to rule out VTE during pregnancy were eligible. RESULTS: We identified 665 references through systematic database and additional search strategies; 45 studies were retrieved in full, of which four were included, after applying exclusion criteria. Three studies were prospective, and one had a retrospective design. The 3‐month thromboembolic rate in pregnant women left untreated after a negative D‐dimer was 1/312 (0.32%; 95% CI, 0.06–1.83). The pooled estimate values were 99.5% for sensitivity (95% CI, 95.0–100.0; I², 0%) and 100% for negative predictive value (95% CI, 99.19–100.0; I², 0%). The prevalence of VTE and the yield of D‐dimer were 7.4% (95% CI, 3.8–12; I², 83%) and 34.2% (95% CI, 15.9–55.23; I², 89%) respectively. CONCLUSION: Our results suggest that D‐dimer allows to safely rule out VTE in pregnant women with suspected VTE and a disease prevalence consistent with a low/intermediate or unlikely pretest probability.