Venous ThromboembolismEarly Phase 1PARTUMNCT04153760
Pilot PARTUM Trial: Postpartum Aspirin to Reduce Thromboembolism Undue Morbidity
A Early Phase 1 study testing Aspirin 81 mg in people with Venous Thromboembolism and Postpartum Period, run by University of Calgary at 7 sites in 4 countries.
Trial summary
The pilot PARTUM trial is a randomized, multicenter, placebo-controlled trial. Women who are at modest risk of VTE (as defined by the inclusion criteria) will be identified during pregnancy, labor and delivery and up to 48 hours postpartum. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Venous Thromboembolism, Postpartum Period, Aspirin
- What is being tested?
- Aspirin 81 mg
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 257 participants
- Where
- 7 sitesin 4 countries
- Study dates
- 7 Oct 2020to 5 Sep 2023
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
None listed.
Who cannot join
- More than 48 hours since delivery
- Received more than 2 doses of low-molecular-weight heparin (LMWH) since delivery
- Need for postpartum LMWH prophylaxis or systemic anticoagulation as judged by the local investigator. May include but is not limited to:
- Documented history of provoked or unprovoked VTE
- Mechanical heart valve(s)
- Known antiphospholipid syndrome
Show all 19Show fewer
- Known high-risk inherited thrombophilia i) Antithrombin deficiency; ii) Homozygous factor V Leiden; iii) Homozygous prothrombin gene mutation; iv) Compound heterozygosity factor V Leiden and prothrombin gene mutation; v) More than one inherited thrombophilia
- Need for postpartum aspirin as judged by the local investigator. May include but is not limited to:
- Documented history of myocardial infarction
- Documented history of ischemic stroke or transient ischemic attack (TIA)
- Contraindication to aspirin including:
- History of known aspirin allergy
- Documented history of a gastrointestinal ulcer
- Known platelet count <50 x 109/L at any time during the current pregnancy or postpartum
- Active bleeding at any site, excluding normal vaginal bleeding, at the time of randomization
- Most recent known hemoglobin ≤70 g/L documented during the current pregnancy or postpartum
- Known severe hypertension (SBP >200mm/hg and/or DBP >120mm/hg) during the current pregnancy or postpartum
- <18 years of age
- Unable or refused consent
Trial locations and contacts
7 sites in 4 countries.
7 sites in 4 countries
Canada4 sites
Foothills Medical Centre
Calgary, Alberta, T2N 2T9
The Ottawa Hospital - General Campus
Ottawa, Ontario, K1H 8L6
Mount Sinai Hospital
Toronto, Ontario, M5G 1Z5
British Columbia Women's Hospital & Health Centre
Vancouver, British Columbia, V6H 3N1
France1 site
Centre Hospitalier Universitaire de Saint-Etienne
Saint-Étienne-de-Montluc, Pays de la Loire Region, 42270
Netherlands1 site
The Amsterdam Medical Centre
Amsterdam, North Holland, 1105
About this study
Official title: A Pilot Study Assessing the Feasibility of a Randomized Controlled Trial Evaluating Aspirin in Postpartum Women at Risk of Developing Venous Thromboembolism
The pilot PARTUM trial is a randomized, multicenter, placebo-controlled trial. Women who are at modest risk of VTE (as defined by the inclusion criteria) will be identified during pregnancy, labor and delivery and up to 48 hours postpartum. Eligible and consenting participants will be randomly assigned to one of two study arms: aspirin 81 mg daily or placebo daily for 6 weeks.
Read the detailed description
The purpose of the pilot PARTUM trial is to determine whether it is feasible to conduct a larger randomized controlled trial to determine whether low-dose aspirin is efficacious and safe at preventing postpartum venous thromboembolism (VTE) in women at increased risk of VTE, compared to placebo.
Given the large sample size needed to adequately power a large multicenter trial that assesses the efficacy of aspirin 81 mg versus placebo, the investigators first need to determine if it is possible to recruit enough women. If the pilot trial is successful and there are no major changes to the study design, then the secondary clinical outcomes collected in the pilot trial will be used in the analysis of the full multicenter trial.
- Conditions
- Venous Thromboembolism, Postpartum Period, Aspirin
- Being tested
- Aspirin 81 mg, Placebo
- Keywords
- deep vein thrombosis, pulmonary embolism, postpartum, pregnancy, thrombophilia, cesarean delivery, pre-eclampsia, postpartum hemorrhage
- Medical subject headings
- Venous Thromboembolism, Venous Thrombosis, Pulmonary Embolism, Thrombophilia, Pre-Eclampsia, Postpartum Hemorrhage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Aspirin 81 mgDrug
Also called acetylsalicylic acid, ASA
Aspirin 81 mg p.o. daily
PlaceboDrug
Placebo p.o. daily
| Study group | Role | What they receive |
|---|---|---|
| Aspirin | Active comparator | Aspirin 81 mg daily for six weeks post-randomization (postpartum) Receives: Drug: Aspirin 81 mg |
| Placebo | Placebo comparator | Placebo daily for six weeks post-randomization (postpartum) Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Recruitment Rate
Mean recruitment rate per center per month
Measured: 6 months
Secondary outcomes (6)
Consent Rate
Proportion of eligible subjects who provide consent
Measured: 6 months
Withdrawals/Loss to Follow-up
Proportion of withdrawals/loss to follow-up among participants
Measured: 9 months
Study Drug Compliance
Level of compliance with study drug through participant recall and medication diary
Measured: 6 months
Time Required to Obtain Site Institutional Approvals
Proportion of sites requiring >18 months to obtain all required approvals/contracts from time of delivery of all study documents.
Measured: 24 months
VTE Event Rate
A more precise estimate of the VTE event rate
Measured: 6 months
Bleeding Event Rate
A more precise estimate of the major and clinically relevant non-major bleeding event rate
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2019
- Study start7 Oct 2020
- Primary completion5 Sep 2023
- Study completion5 Sep 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Venous ThromboembolismStudies of the same condition, open and under way.
- More trials run by University of CalgaryThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 257 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Calgary
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR), Canadian Venous Thromboembolism Clinical Trials and Outcomes Research (CanVECTOR) Network
- Responsible party
- Sponsor
- Investigators
- Leslie Skeith, MD, Principal investigator, University of CalgaryMarc Rodger, MD, Principal investigator, McGill University Health Centre/Research Institute of the McGill University Health Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04153760
- Sponsor's protocol ID
- REB19-1237
- Acronym
- PARTUM
- Status last verified
- Sep 2023
- First submitted
- 4 Nov 2019
- Last updated
- 13 Sep 2023
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Skeith L, Malinowski AK, El-Chaar D, Chan WS, Donnelly J, Chauleur C, Ganzevoort W, Wood S, Dubois S, McCarthy C, Buchmuller A, Wiegers H, Gibson PS, Ni Ainle F, Middeldorp S, Duffett L, Bates SM, Garven A, Baxter J, Lethebe BC, Rodger MA; Pilot PARTUM Group. Low-dose aspirin versus placebo in postpartum venous thromboembolism: a multi-national, pilot, randomised, placebo-controlled trial. Lancet Haematol. 2025 Feb;12(2):e109-e119. doi: 10.1016/S2352-3026(24)00338-7. Epub 2025 Jan 16.
PubMed 39827892Blondon M, Claver M, Celetta E, Righini M, de Tejada BM. Preventing Postpartum Venous Thromboembolism With Low-Molecular-Weight Heparin: The PP-HEP Pilot Randomised Controlled Trial. BJOG. 2025 Jan;132(1):35-43. doi: 10.1111/1471-0528.17943. Epub 2024 Sep 5.
PubMed 39238110Middleton P, Shepherd E, Gomersall JC. Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period. Cochrane Database Syst Rev. 2021 Mar 29;3(3):CD001689. doi: 10.1002/14651858.CD001689.pub4.
PubMed 33779986
Study at a glance
From the registry record, last updated by the sponsor on 13 Sep 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study Assessing the Feasibility of a Randomized Controlled Trial Evaluating Aspirin in Postpartum Women at Risk of Developing Venous Thromboembolism
- ClinicalTrials.gov ID
- NCT04153760
- Acronym / sponsor ID
- PARTUM / REB19-1237
- Conditions
- Venous Thromboembolism, Postpartum Period, Aspirin
- Keywords
- deep vein thrombosis, pulmonary embolism, postpartum, pregnancy, thrombophilia, cesarean delivery, pre-eclampsia, postpartum hemorrhage
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 257 participants (actual)
- Lead sponsor
- University of CalgaryUniversity, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR), Canadian Venous Thromboembolism Clinical Trials and Outcomes Research (CanVECTOR) Network
- Study start
- 7 Oct 2020 (actual)
- Primary completion
- 5 Sep 2023 (actual)
- Study completion
- 5 Sep 2023 (actual)
- First posted
- 6 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The pilot PARTUM trial is a randomized, multicenter, placebo-controlled trial. Women who are at modest risk of VTE (as defined by the inclusion criteria) will be identified during pregnancy, labor and delivery and up to 48 hours postpartum. Eligible and consenting participants will be randomly assigned to one of two study arms: aspirin 81 mg daily or placebo daily for 6 weeks.
Detailed description
The purpose of the pilot PARTUM trial is to determine whether it is feasible to conduct a larger randomized controlled trial to determine whether low-dose aspirin is efficacious and safe at preventing postpartum venous thromboembolism (VTE) in women at increased risk of VTE, compared to placebo.
Given the large sample size needed to adequately power a large multicenter trial that assesses the efficacy of aspirin 81 mg versus placebo, the investigators first need to determine if it is possible to recruit enough women. If the pilot trial is successful and there are no major changes to the study design, then the secondary clinical outcomes collected in the pilot trial will be used in the analysis of the full multicenter trial.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Aspirin | Active comparator | Drug: Aspirin 81 mgAspirin 81 mg daily for six weeks post-randomization (postpartum) |
| Placebo | Placebo comparator | Drug: PlaceboPlacebo daily for six weeks post-randomization (postpartum) |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (0 listed)
Key exclusion criteria (19 listed)
- More than 48 hours since delivery
- Received more than 2 doses of low-molecular-weight heparin (LMWH) since delivery
- Need for postpartum LMWH prophylaxis or systemic anticoagulation as judged by the local investigator. May include but is not limited to:
- Need for postpartum aspirin as judged by the local investigator. May include but is not limited to:
- Contraindication to aspirin including:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Aspirin 81 mgAlso: acetylsalicylic acid, ASAAspirin 81 mg p.o. daily | Drug | Aspirin |
| PlaceboPlacebo p.o. daily | Drug | Placebo |
Primary outcome
Recruitment Rate
Time frame: 6 months
Mean recruitment rate per center per month
6 secondary outcomes
Consent Rate
Time frame: 6 months
Withdrawals/Loss to Follow-up
Time frame: 9 months
Study Drug Compliance
Time frame: 6 months
Time Required to Obtain Site Institutional Approvals
Time frame: 24 months
VTE Event Rate
Time frame: 6 months
Bleeding Event Rate
Time frame: 6 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Sep 2023.
- Derived from this study: PubMed 39827892Skeith L, Malinowski AK, El-Chaar D, Chan WS, Donnelly J, Chauleur C, Ganzevoort W, Wood S, Dubois S, McCarthy C, Buchmuller A, Wiegers H, Gibson PS, Ni Ainle F, Middeldorp S, Duffett L, Bates SM, Garven A, Baxter J, Lethebe BC, Rodger MA; Pilot PARTUM Group. Low-dose aspirin versus placebo in postpartum venous thromboembolism: a multi-national, pilot, randomised, placebo-controlled trial. Lancet Haematol. 2025 Feb;12(2):e109-e119. doi: 10.1016/S2352-3026(24)00338-7. Epub 2025 Jan 16.
- Derived from this study: PubMed 39238110Blondon M, Claver M, Celetta E, Righini M, de Tejada BM. Preventing Postpartum Venous Thromboembolism With Low-Molecular-Weight Heparin: The PP-HEP Pilot Randomised Controlled Trial. BJOG. 2025 Jan;132(1):35-43. doi: 10.1111/1471-0528.17943. Epub 2024 Sep 5.
- Derived from this study: PubMed 33779986Middleton P, Shepherd E, Gomersall JC. Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period. Cochrane Database Syst Rev. 2021 Mar 29;3(3):CD001689. doi: 10.1002/14651858.CD001689.pub4.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Leslie Skeith, MD principal investigator
University of Calgary
Marc Rodger, MD principal investigator
McGill University Health Centre/Research Institute of the McGill University Health Centre
7 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Aspirin 81 mg in people with Venous Thromboembolism and Postpartum Period, run by University of Calgary at 7 sites in 4 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 0 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Sep 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Canada, France, Ireland, Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Recruitment Rate (time frame: 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04153760, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Sep 2023.