Deep Vein Thrombosis, Pulmonary Embolism, Venous Thromboembolism
Conditions
Keywords
venous thromboembolism, thromboembolism, deep vein thrombosis, pulmonary embolism, thromboprophylaxis, thrombosis, embolism and thrombosis, cardiovascular diseases, venous thrombosis, vascular diseases, anticoagulants, hematologic agents, cardiovascular agents, enoxaparin, dalteparin, tinzaparin, pregnancy complications
Brief summary
Pregnant women with a prior history of venous thromboembolism (VTE) are at increased risk of recurrent VTE. Current guidelines assessing the role of prophylaxis in pregnant women with prior VTE are based primarily on expert opinion and the optimal clinical management strategy remains unclear. This multicentre, prospective cohort study aims to test the following hypotheses: 1. Antepartum prophylaxis with fixed-dose low molecular-weight heparin (LMWH) is safe, convenient and associated with an acceptably low risk of recurrent VTE in women with a single prior episode of VTE that was either unprovoked or associated with a minor transient risk factor. (Moderate risk cohort) 2. Withholding antepartum prophylaxis is safe (recurrence risk \<1%) in pregnant women with a single prior episode of VTE provoked by a major transient risk factor. (Low risk cohort) All study patients will receive 6 weeks of postpartum prophylaxis.
Interventions
None listed
Sponsors
St. Joseph's Healthcare Hamilton
Hamilton Health Sciences Corporation
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Confirmed pregnancy (positive serum or urine) * At least 18 years of age * History of one prior episode of VTE consisting of DVT (diagnosed by compression ultrasonography \[CUS\] or venography) and/or PE (diagnosed by ventilation-perfusion \[V/Q\] lung scintigraphy, computed tomographic pulmonary angiography \[CTPA\], or traditional pulmonary angiography)
Exclusion criteria
* Ongoing need for therapeutic anticoagulation for prevention or treatment of cardioembolic stroke * Known high-risk thrombophilia (specifically antithrombin deficiency, protein S deficiency, protein C deficiency, homozygosity for the factor V Leiden or prothrombin G20210A mutations, antiphospholipid antibody or compound abnormalities) * VTE within 3 months of the current pregnancy * Clinical risk factor for initial episode of VTE, if present, not resolved (excluding pregnancy) * Known contraindication to anticoagulation (including active, uncontrolled bleeding or major bleed within the previous 4 weeks) * For patients with prior unprovoked VTE, contraindication to LMWH (including allergy, HIT, impaired renal function, osteoporosis) * Geographic or social factors precluding follow-up * Inability or unwillingness to provide informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Symptomatic venous thromboembolism | antepartum period (expected average 7 months) | Symptomatic objectively confirmed recurrent VTE, including proximal DVT, non-fatal PE, and fatal PE during antepartum period |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Symptomatic recurrent pulmonary embolism | antepartum period (expected average 7 months) and first 3 months postpartum | Symptomatic objectively confirmed recurrent PE antepartum and within first 3 months postpartum |
| Thrombocytopenia or heparin-induced thrombocytopenia (HIT) | antepartum period (expected average 7 months) | Thrombocytopenia or HIT during antepartum period |
| Symptomatic osteoporosis | antepartum period (expected average 7 months) and first 3 months postpartum | Symptomatic osteoporosis antepartum and within first 3 months postpartum |
| Symptomatic recurrent venous thromboembolism | antepartum period (expected average 7 months) and first 3 months postpartum | Symptomatic recurrent VTE antepartum and within first 3 months postpartum |
| Pregnancy complications and outcomes | antepartum period (expected average 7 months) | Pregnancy complications and outcomes including fetal death, pre-eclampsia, toxemia, intrauterine growth restriction, prematurity during antepartum period |
| Fetal anomalies | antepartum (expected average 7 months) and during first 3 months postpartum | Fetal anomalies |
| Major and minor bleeding | antepartum (expected average 7 months) | Major and minor bleeding |
| Other complications | antepartum (expected average 7 months) and within first 3 months postpartum | Other complications sufficient to stop treatment (e.g., local and systemic reactions) antepartum and within first 3 months postpartum |
Countries
Canada
Contacts
Primary ContactShannon M Bates, MD
Backup ContactNancy Lloyd, MSc
Outcome results
None listed