The PARTUM Trial: Postpartum Aspirin to Reduce Thromboembolism Undue Morbidity

Inclusion criteria

• ONE (or more) First Order Criterion:
• 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
• 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:
• Pre-pregnancy BMI ≥30 kg/m²
• Smoking in the current pregnancy or within 3 months prior to pregnancy
• Previous clinical history of superficial vein thrombosis
• Preeclampsia
• Current pregnancy ending in stillbirth (pregnancy loss \>20 weeks gestation)
• Unplanned cesarean delivery (unplanned = not a scheduled cesarean delivery)
• Small-for-gestational-age infant at time of delivery (\<3rd percentile adjusted for gestational age and sex)
• Peripartum or postpartum infection (symptoms/signs of infection and documented fever and laboratory evidence of infection with positive blood cultures or an elevated white blood cell count based on local laboratory cutoffs)
• Postpartum hemorrhage (≥1000 mL of blood loss, regardless of delivery mode)

Exclusion criteria

• More than 48 hours since delivery at the time of randomization
• Received more than 1 dose of LMWH since delivery
• Need for postpartum LMWH prophylaxis or systemic anticoagulation as judged by their physician and/or local investigator. May include but is not limited to:
• Documented history of provoked or unprovoked VTE
• Mechanical heart valve(s)
• Known antiphospholipid syndrome (APS)
• Known high-risk inherited thrombophilia i) Antithrombin deficiency, or ii) Homozygous factor V Leiden, or iii) Homozygous prothrombin gene mutation, or iv) More than 1 thrombophilia: any combination of 2 or more: factor V Leiden, prothrombin gene mutation, protein C deficiency, protein S deficiency
• Need for postpartum ASA as judged by their physician and/or local investigator. May include but is not limited to:
• Documented history of myocardial infarction
• Documented history of ischemic stroke or transient ischemic attack (TIA)
• Active bleeding, excluding normal vaginal bleeding, at the time of randomization
• Known medical condition as judged by their physician and/or local investigator to be a contraindication to ASA or LMWH including known ASA or LMWH allergy
• \<18 years of age
• Unable or declined consent