The PARTUM Trial: Postpartum Aspirin to Reduce Thromboembolism Undue Morbidity

The goal of the PARTUM trial is to determine if taking low-dose aspirin daily for 6 weeks after delivery is similar (non-inferior) to usual care low-molecular-weight heparin injections to prevent venous thromboembolism (VTE: blood clots in the legs or lungs) for postpartum individuals with VTE risk factors.

Inclusion Criteria: * ONE (or more) First Order Criterion: 1. Known inherited thrombophilia diagnosed prior to enrolment, regardless of family history of VTE: i. Heterozygous factor V Leiden, or ii. Heterozygous prothrombin gene variant, or iii. Protein C deficiency, or iv. Protein S deficiency, and/or 2. Antepartum immobilization for ≥7 days. Immobilization is defined as bed rest with 90% of waking hours spent in bed at any time during the antepartum period AND/OR TWO (or more) Second Order Criteria: 1. Pre-pregnancy BMI ≥30 kg/m² 2. Smoking in the current pregnancy or within 3 months prior to pregnancy 3. Previous clinical history of superficial vein thrombosis 4. Preeclampsia 5. Current pregnancy ending in stillbirth (pregnancy loss \>20 weeks gestation) 6. Unplanned cesarean delivery (unplanned = not a scheduled cesarean delivery) 7. Small-for-gestational-age infant at time of delivery (\