PreeclampsiaNCT04974892
Aspirin and Neutrophils in Preeclampsia
An observational study of Preeclampsia and Neutrophil, run by Queen Mary University of London at 1 site in United Kingdom.
Trial summary
The exact mechanisms by which aspirin prevents the development of preeclampsia in high-risk patients are currently not fully known. Furthermore, a small proportion of high-risk patients who are on low-dose aspirin (LDA) still go on to develop preeclampsia (PE). Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Preeclampsia, Neutrophil, Immunology
- What is being tested?
- Blood test
- How many people
- 35 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 27 Apr 2022to 31 Dec 2025
- How long will I take part?
- 24 Weeks
- Phase
- Observational
- 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
Study population: Patients at high risk of developing preeclampsia in pregnancy who are started on low dose aspirin at ≤16 weeks.
Who may be able to join
- Age 18-60 years
- Singleton pregnancy
- Live fetus at 11-13 weeks of gestation
- Informed, written consent
- Upper age of 60 years
- Patient taking low dose aspirin as standard of care
Who cannot join
- Unwilling or unable to give consent
- Participants who are unable to understand written English
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Barts Health NHS Trust, The Royal London Hospital
London, E1 1BB
About this study
Official title: Investigating the Role of Neutrophils in Aspirin Treatment for Women at High Risk of Preeclampsia
The exact mechanisms by which aspirin prevents the development of preeclampsia in high-risk patients are currently not fully known. Furthermore, a small proportion of high-risk patients who are on low-dose aspirin (LDA) still go on to develop preeclampsia (PE).
This longitudinal observational study will assess the immune profile in participants who are taking low dose aspirin (LDA) in pregnancy. As part of routine care, patients at high risk of developing preeclampsia are treated with LDA from 16 weeks gestation.
Read more
The study will be conducted at Barts Health National Health Service (NHS) Trust. The study population will comprise of 2 groups of participants:
- Those who respond to LDA and do not develop preeclampsia (responders)
- Participants who do not respond to LDA and develop preeclampsia (non responders)
Participants will be consented at their booking appointment. Participants will be eligible if they have a singleton pregnancy and are aged over 18 years. They will have an additional blood sample taken at 12, 20, 28 and 36 weeks gestation.
The blood samples will be tested to assess immune cell function, metabolism and genetics. This will identify cumulative changes in immunobiology at key time points in pregnancy.
Read the detailed description
The exact mechanisms by which aspirin prevents the development of PE in high-risk patients are currently not fully known. Furthermore, a small proportion of high-risk patients who are on low-dose aspirin still go on to develop PE. This is a big unmet need because although it is known that this treatment is working for some patients, it is not known how it's working in these patients and also why a proportion of patients don't respond to this treatment. If the key mechanisms by which aspirin treatment is beneficial in patients at high risk of PE can be identifies, this will lead to better information for clinicians of why this treatment works and this could then be conveyed to the patient. Moreover, if key differences can be identified between aspirin responders and non-responders, novel therapeutic targets could be developed that could work for all patients at high risk of PE.
One of the main anti-inflammatory actions of aspirin is the release of aspirin-triggered lipoxin (ATL). The receptor for ATL (FPR2/ALX) is highly expressed on neutrophils, suggesting that the anti-inflammatory action of this drug is mediated via neutrophils. The investigators have previously shown that neutrophils are important in mediating anti-inflammatory responses in PE. Thus, taken together, the hypothesis is that neutrophils are key to understanding the mechanisms involved in the use of low-dose aspirin (LDA) treatment in patients at high risk of developing PE and key to understanding why this treatment does not work in some high-risk patients. This hypothesis will be addressed by two objectives both of which will entail in-depth profiling of neutrophils.
- Conditions
- Preeclampsia, Neutrophil, Immunology, Pregnancy
- Being tested
- Blood test
- Medical subject headings
- Pre-Eclampsia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood testDiagnostic test
Blood tests will be taken at 12, 20, 28 and 36 weeks gestation to assess the immune profile and omic profile.
| Study group | Role | What they receive |
|---|---|---|
| low dose aspirin | high-risk women given LDA at ≤16 weeks. Receives: Diagnostic Test: Blood test | |
| Non responders to low dose aspirin | high-risk women who have not responded to LDA and have gone on to develop PE. Receives: Diagnostic Test: Blood test |
What is being measured
The primary outcome is the main question the study is designed to answer.
To longitudinally define the neutrophil profile in high-risk patients given low dose aspirin (LDA) at ≤16 weeks.
To address the first objective, to assess the neutrophil profile in high-risk patients given LDA at ≤16 weeks, a longitudinal analyses will be undertaken of neutrophils taken from participants at high-risk of PE (as identified at their pregnancy booking appointment). The first blood test will occur prior to aspirin commencement and be repeated at 3 other time points in pregnancy. These longitudinal analyses will identify cumulative changes in neutrophils following the commencement of aspirin treatment and pinpoint key timepoints of aspirin on neutrophil biology.
Measured: 2 years
To define the neutrophil profile in a cohort of high-risk patients who have not responded to low dose aspirin (LDA) and have gone on to develop PE.
To address the second objective (to assess the neutrophil profile in a cohort of high-risk patients who have not responded to LDA and have gone on to develop PE), 20 LDA non-responders subsequently develop PE will be identified.
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jul 2021
- Study start27 Apr 2022
- Primary completion31 Dec 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PreeclampsiaStudies of the same condition, open and under way.
- More trials run by Queen Mary University of LondonThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 35 participants (actual)
- Target duration
- 24 Weeks
Sponsor and investigators
- Lead sponsor
- Queen Mary University of London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04974892
- Sponsor's protocol ID
- IRAS 294761
- Status last verified
- Apr 2026
- First submitted
- 21 May 2021
- Last updated
- 23 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Role of Neutrophils in Aspirin Treatment for Women at High Risk of Preeclampsia
- ClinicalTrials.gov ID
- NCT04974892
- Acronym / sponsor ID
- IRAS 294761
- Conditions
- Preeclampsia, Neutrophil, Immunology, Pregnancy
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 35 participants (actual)
- Lead sponsor
- Queen Mary University of LondonUniversity, hospital or other
- Study start
- 27 Apr 2022 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 23 Jul 2021 (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 exact mechanisms by which aspirin prevents the development of preeclampsia in high-risk patients are currently not fully known. Furthermore, a small proportion of high-risk patients who are on low-dose aspirin (LDA) still go on to develop preeclampsia (PE).
This longitudinal observational study will assess the immune profile in participants who are taking low dose aspirin (LDA) in pregnancy. As part of routine care, patients at high risk of developing preeclampsia are treated with LDA from 16 weeks gestation.
The study will be conducted at Barts Health National Health Service (NHS) Trust. The study population will comprise of 2 groups of participants:
- Those who respond to LDA and do not develop preeclampsia (responders)
- Participants who do not respond to LDA and develop preeclampsia (non responders)
Participants will be consented at their booking appointment. Participants will be eligible if they have a singleton pregnancy and are aged over 18 years. They will have an additional blood sample taken at 12, 20, 28 and 36 weeks gestation.
The blood samples will be tested to assess immune cell function, metabolism and genetics. This will identify cumulative changes in immunobiology at key time points in pregnancy.
Detailed description
The exact mechanisms by which aspirin prevents the development of PE in high-risk patients are currently not fully known. Furthermore, a small proportion of high-risk patients who are on low-dose aspirin still go on to develop PE. This is a big unmet need because although it is known that this treatment is working for some patients, it is not known how it's working in these patients and also why a proportion of patients don't respond to this treatment. If the key mechanisms by which aspirin treatment is beneficial in patients at high risk of PE can be identifies, this will lead to better information for clinicians of why this treatment works and this could then be conveyed to the patient. Moreover, if key differences can be identified between aspirin responders and non-responders, novel therapeutic targets could be developed that could work for all patients at high risk of PE.
One of the main anti-inflammatory actions of aspirin is the release of aspirin-triggered lipoxin (ATL). The receptor for ATL (FPR2/ALX) is highly expressed on neutrophils, suggesting that the anti-inflammatory action of this drug is mediated via neutrophils. The investigators have previously shown that neutrophils are important in mediating anti-inflammatory responses in PE. Thus, taken together, the hypothesis is that neutrophils are key to understanding the mechanisms involved in the use of low-dose aspirin (LDA) treatment in patients at high risk of developing PE and key to understanding why this treatment does not work in some high-risk patients. This hypothesis will be addressed by two objectives both of which will entail in-depth profiling of neutrophils.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 24 Weeks
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| low dose aspirin | – | Diagnostic Test: Blood testhigh-risk women given LDA at ≤16 weeks. |
| Non responders to low dose aspirin | – | Diagnostic Test: Blood testhigh-risk women who have not responded to LDA and have gone on to develop PE. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients at high risk of developing preeclampsia in pregnancy who are started on low dose aspirin at ≤16 weeks.
Key inclusion criteria (6 listed)
- Age 18-60 years
- Singleton pregnancy
- Live fetus at 11-13 weeks of gestation
- Informed, written consent
- Upper age of 60 years
Key exclusion criteria (2 listed)
- Unwilling or unable to give consent
- Participants who are unable to understand written English
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 |
|---|---|---|
| Blood testBlood tests will be taken at 12, 20, 28 and 36 weeks gestation to assess the immune profile and omic profile. | Diagnostic test | Non responders to low dose aspirin, low dose aspirin |
Primary outcome
To longitudinally define the neutrophil profile in high-risk patients given low dose aspirin (LDA) at ≤16 weeks.
Time frame: 2 years
To address the first objective, to assess the neutrophil profile in high-risk patients given LDA at ≤16 weeks, a longitudinal analyses will be undertaken of neutrophils taken from participants at high-risk of PE (as identified at their pregnancy booking appointment). The first blood test will occur prior to aspirin commencement and be repeated at 3 other time points in pregnancy. These longitudinal analyses will identify cumulative changes in neutrophils following the commencement of aspirin treatment and pinpoint key timepoints of aspirin on neutrophil biology.
To define the neutrophil profile in a cohort of high-risk patients who have not responded to low dose aspirin (LDA) and have gone on to develop PE.
Time frame: 2 years
To address the second objective (to assess the neutrophil profile in a cohort of high-risk patients who have not responded to LDA and have gone on to develop PE), 20 LDA non-responders subsequently develop PE will be identified.
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 23 Apr 2026.
- 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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Preeclampsia and Neutrophil, run by Queen Mary University of London at 1 site in United Kingdom.
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 6 inclusion and 2 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 23 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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?
To longitudinally define the neutrophil profile in high-risk patients given low dose aspirin (LDA) at ≤16 weeks. (time frame: 2 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Apr 2026.