Postthrombotic Syndrome and Chronic Pulmonary Embolism after Obstetric Venous Thromboembolism

Objective  While the majority of venous thromboembolism (VTE) during pregnancy events resolve with anticoagulation, long-term complications may occur including (1) postthrombotic syndrome and (2) chronic pulmonary embolism. The objective of this study was to determine risk of these two complications. Study Design  A retrospective cohort study using the MarketScan databases was performed on deliveries from 2008 to 2014. We identified women aged 15 to 54 years diagnosed with acute VTE during pregnancy, the delivery hospitalization, or ≤60 days postpartum who received at least one prescription postpartum for anticoagulants. Risks of (1) chronic PE and (2) postthrombotic syndrome were evaluated for women at 6, 12, 24, and 60 months after delivery hospitalization through 2017 via the International Classification of Diseases, 9th/10th Revision, Clinical Modification codes. Results  Of 4,267 of 4,128,900 pregnancies complicated by VTE, the majority had DVT alone (61.8%, n = 2,637), while 25.8% had PE alone (n = 1,103) and 12.4% (n = 527) had both DVT and PE. Of the entire cohort, 3,328 retained insurance coverage at 6 months, 2,823 at 12 months, 2,161 at 24 months, and 831 at 60 months. Restricted to DVT, risk of postthrombotic syndrome was 0.7% at 6 months (n = 17), 1.1% at 12 months (n = 22), 1.7% at 24 months (n = 26), and 2.7% at 60 months (n = 16). Among women with PE diagnoses, the risk of chronic PE was 2.4% at 6 months (n = 30), 3.3% at 12 months (n = 36), 4.2% at 24 months (n = 36), and 7.2% at 60 months (n = 24). Conclusion  In comparison to the general population, the risk of postthrombotic syndrome was lower. In comparison, the risk of chronic PE was similar to the estimates in the general population at comparable time points after PE events. For women with obstetric PE, it may be appropriate to be vigilant for findings and symptoms associated with chronic PE. Key Points Risk of postthrombotic syndrome after obstetric deep vein thrombosis is low. Risk of chronic pulmonary embolism may approximate that in the general population. Overall risk of chronic complications after obstetric VTE was relatively low.