Preterm BirthPhase 1/2DASHNCT06826859
Daily Aspirin vs Split Dosing in High-risk Pregnancies (DASH)
A Phase 1/2 study testing Daily aspirin (ASA) and Split dose aspirin (ASA) in people with Preterm Birth and Preeclampsia, run by Thomas Jefferson University at 1 site in United States.
Trial summary
Aspirin is recommended in high risk patients to reduce the risk of preeclampsia and preterm birth, which are leading causes of both maternal and neonatal morbidity and mortality, but up to 20% will have these adverse outcomes despite therapy. Read more about this study
- Who is it for?
- Ages 16 to 55 years, women only
- Conditions the study is for
- Preterm Birth, Preeclampsia
- What is being tested?
- Daily aspirin (ASA) and Split dose aspirin (ASA)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 400 participants
- Where
- 1 siteUnited States
- Study dates
- 26 Jun 2025to 31 Dec 2029
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
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 16 to 55 years
- Women only
- No healthy volunteers
- Child, Adult
Who may be able to join
- Singleton gestation gestational age <16 0/7 weeks, dating confirmed with ultrasound
- ≥1 high risk factor for preeclampsia or ≥2 moderate risk factors as per United States Preventative Services Task Force (2021)
- Recommendation for 162mg aspirin daily in pregnancy
- Age 16-55 years old
Who cannot join
- Contraindication to aspirin
- Current or planned use of any other anticoagulation
- Thrombocytopenia, other known platelet or bleeding disorder
- Abnormally elevated baseline PFA-100 epinephrine closure time prior to aspirin initiation
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Thomas Jefferson University
Philadelphia, Pennsylvania, 19060
Rupsa C Boelig, MD, 215-955-5000, rupsa.boelig@jefferson.edu
Brandy Firman, brandy.firman@jeffereson.edu
About this study
Official title: Dose Based Aspirin Pharmacokinetics and Pharmacodynamics in Pregnancy and Association With Pregnancy Outcomes
Aspirin is recommended in high risk patients to reduce the risk of preeclampsia and preterm birth, which are leading causes of both maternal and neonatal morbidity and mortality, but up to 20% will have these adverse outcomes despite therapy. Gaps in knowledge regarding pregnancy specific aspirin pharmacology and the relationship of aspirin response and pregnancy outcome, along with a lack of consensus on aspirin dosing has limited the effective use of this intervention. The investigators aim to apply principles of clinical pharmacology to determine how to optimally utilize this low cost medication to improve maternal/child health outcomes. This is a Phase I/II randomized controlled trial of high risk pregnancies recommended aspirin; participants will be randomized to take aspirin either 162mg once daily, or 81mg twice a day. Outcomes evaluated will include the difference in aspirin response between these two dosing regimens, the individual factors that impact aspirin pharmacology in pregnancy, and evaluate markers or aspirin response that may be associated with pregnancy outcome.
Read the detailed description
This is an unblinded randomized controlled Phase I/II trial comparing high risk singleton pregnancies randomized to 162mg daily (daily dose) vs 81mg q12hours (split dose). Participants will be enrolled prior to 16 weeks gestation. The primary outcome is platelet inhibition as assessed by PFA-100 epinephrine closure time, assessed 2-4 weeks after initiation and again at 28-32 weeks gestation. A subset of participants will be enrolled in a pharmacokinetic study to evaluate pharmacokinetics of aspirin in pregnancy at the two dosing intervals. Secondary outcomes include urine thromboxane at each visit, platelet associated microRNAs. Individual factors associated with aspirin pharmacokinetics and pharmacodynamics in pregnancy will be assessed. Finally, the relationship between these pharmacodynamic markers and pregnancy outcome will be evaluated.
- Conditions
- Preterm Birth, Preeclampsia
- Being tested
- Daily aspirin (ASA), Split dose aspirin (ASA)
- Keywords
- Aspirin, Preeclampsia, Preterm birth, Pregnancy, Pharmacokinetics, Pharmacodynamics, Phase I/II, Randomized clinical trial
- Medical subject headings
- Premature Birth, Pre-Eclampsia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Daily aspirin (ASA)Drug
162mg aspirin taken daily
Split dose aspirin (ASA)Drug
81mg aspirin q12hours
| Study group | Role | What they receive |
|---|---|---|
| Daily aspirin | Active comparator | 162mg aspirin daily Receives: Drug: Daily aspirin (ASA) |
| Split dose aspirin | Experimental | 81mg aspirin q12 hours Receives: Drug: Split dose aspirin (ASA) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Aspirin Response PFA-100 epinephrine closure time (seconds)
Difference in PFA-100 epinephrine closure time (seconds)
Measured: 2-4 weeks after aspirin initiation
Secondary outcomes (25)
Aspirin response (PFA-100 epinephrine closure time)
Difference in PFA-100 epinephrine closure time (seconds)
Measured: 28-32 weeks gestation
Urinary thromboxane concentration
Difference in Urine thromboxane (AspirinWorks)
Measured: 2-4 weeks after aspirin initiation
Urinary Thromboxane concentration
Difference in Urinary thromboxane (AspirinWorks)
Measured: 28-32 weeks gestation
Inadequate aspirin response
Number of participants with PFA-100 epinephrine closure time<150 seconds
Measured: 2-4 weeks after aspirin initiation
Inadequate aspirin response
Number of participants with PFA-100 epinephrine closure time<150seconds
Measured: 28-32 weeks gestation
Preterm birth
Number of participants with Preterm birth<37 weeks
Measured: Delivery
Indicated preterm birth
Number of participants with Preterm birth<37 weeks due to preeclampsia or fetal growth restriction
Measured: delivery
Spontaneous preterm birth
Number of participants with spontaneous preterm birth <37 weeks
Measured: delivery
MicroRNAs
Fold-change from baseline for concentration of circulating microRNAs
Measured: 2-4 weeks after aspirin initiation
MicroRNAs
Fold-change from baseline for concentration of circulating microRNAs
Measured: 28-32 weeks gestation
Placental histopathology
Placental pathology per Amsterdam criteria. Number of participants with maternal vascular malperfusion, intervillous thrombosis
Measured: Delivery
Birthweight
Infant birthweight (grams)
Measured: Delivery
Fetal growth restriction
Number of participants diagnosed with Fetal growth restriction
Measured: delivery
Hypertensive disorder of pregnancy
Number of participants diagnosed with Preeclampsia or gestational hypertension
Measured: delivery
Gestational age at delivery
Gestational age at delivery (weeks)
Measured: Delivery
Pregnancy loss<20 weeks
Number of participants with Pregnancy loss (delivery, demise, miscarriage)<20 weeks gestation
Measured: delivery
Fetal demise
Number of participants with Fetal demise diagnosed >=20 weeks gestation
Measured: delivery
Antepartum bleeding
Number of participants with any admission for antepartum bleeding
Measured: Delivery
Abruption
Number of participants with Abruption diagnosed prior to or at delivery
Measured: delivery
Placental hematoma
Number of participants with Placental hematoma suspected on ultrasound
Measured: delivery
Postpartum hemorrhage
Number of participants with Postpartum hemorrhage >1000ml
Measured: Delivery
Adherence
Number of participants with Adherence>75%
Measured: 2-4 weeks after aspirin
Adherence
Number of participants with Adherence>75%
Measured: 28-32 weeks
Neonatal intraventricular hemorrhage Grade II or higher
Number of participants with infants found to have Neonatal IVH grade II or higher diagnosed on ultrasound post natally
Measured: Neonatal discharge
Cordblood serum thromboxane
cordblood serum thromboxane concentration
Measured: Delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Feb 2025
- Study start26 Jun 2025
- Primary completion1 Jul 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Preterm BirthStudies of the same condition, open and under way.
- More trials run by Thomas Jefferson UniversityThe 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
- Phase 1/2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Thomas Jefferson University
- Sponsor type
- University, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06826859
- Sponsor's protocol ID
- IRISID-2024-1554
- Other IDs
- 1R01HD112076
- Acronym
- DASH
- Status last verified
- Jul 2025
- First submitted
- 28 Jan 2025
- Last updated
- 17 Jul 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data will be submitted to NICHD DASH and can be requested through NICHD DASH
Study at a glance
From the registry record, last updated by the sponsor on 17 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dose Based Aspirin Pharmacokinetics and Pharmacodynamics in Pregnancy and Association With Pregnancy Outcomes
- ClinicalTrials.gov ID
- NCT06826859
- Acronym / sponsor ID
- DASH / IRISID-2024-1554
- Conditions
- Preterm Birth, Preeclampsia
- Keywords
- Aspirin, Preeclampsia, Preterm birth, Pregnancy, Pharmacokinetics, Pharmacodynamics, Phase I/II, Randomized clinical trial
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Thomas Jefferson UniversityUniversity, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Study start
- 26 Jun 2025 (actual)
- Primary completion
- 1 Jul 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 14 Feb 2025 (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.
Aspirin is recommended in high risk patients to reduce the risk of preeclampsia and preterm birth, which are leading causes of both maternal and neonatal morbidity and mortality, but up to 20% will have these adverse outcomes despite therapy. Gaps in knowledge regarding pregnancy specific aspirin pharmacology and the relationship of aspirin response and pregnancy outcome, along with a lack of consensus on aspirin dosing has limited the effective use of this intervention. The investigators aim to apply principles of clinical pharmacology to determine how to optimally utilize this low cost medication to improve maternal/child health outcomes. This is a Phase I/II randomized controlled trial of high risk pregnancies recommended aspirin; participants will be randomized to take aspirin either 162mg once daily, or 81mg twice a day. Outcomes evaluated will include the difference in aspirin response between these two dosing regimens, the individual factors that impact aspirin pharmacology in pregnancy, and evaluate markers or aspirin response that may be associated with pregnancy outcome.
Detailed description
This is an unblinded randomized controlled Phase I/II trial comparing high risk singleton pregnancies randomized to 162mg daily (daily dose) vs 81mg q12hours (split dose). Participants will be enrolled prior to 16 weeks gestation. The primary outcome is platelet inhibition as assessed by PFA-100 epinephrine closure time, assessed 2-4 weeks after initiation and again at 28-32 weeks gestation. A subset of participants will be enrolled in a pharmacokinetic study to evaluate pharmacokinetics of aspirin in pregnancy at the two dosing intervals. Secondary outcomes include urine thromboxane at each visit, platelet associated microRNAs. Individual factors associated with aspirin pharmacokinetics and pharmacodynamics in pregnancy will be assessed. Finally, the relationship between these pharmacodynamic markers and pregnancy outcome will be evaluated.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Daily aspirin | Active comparator | Drug: Daily aspirin (ASA)162mg aspirin daily |
| Split dose aspirin | Experimental | Drug: Split dose aspirin (ASA)81mg aspirin q12 hours |
Who may qualify
- Ages
- 16 to 55 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- Singleton gestation gestational age <16 0/7 weeks, dating confirmed with ultrasound
- ≥1 high risk factor for preeclampsia or ≥2 moderate risk factors as per United States Preventative Services Task Force (2021)
- Recommendation for 162mg aspirin daily in pregnancy
- Age 16-55 years old
Key exclusion criteria (4 listed)
- Contraindication to aspirin
- Current or planned use of any other anticoagulation
- Thrombocytopenia, other known platelet or bleeding disorder
- Abnormally elevated baseline PFA-100 epinephrine closure time prior to aspirin initiation
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 |
|---|---|---|
| Daily aspirin (ASA)162mg aspirin taken daily | Drug | Daily aspirin |
| Split dose aspirin (ASA)81mg aspirin q12hours | Drug | Split dose aspirin |
Primary outcome
Aspirin Response PFA-100 epinephrine closure time (seconds)
Time frame: 2-4 weeks after aspirin initiation
Difference in PFA-100 epinephrine closure time (seconds)
25 secondary outcomes
Aspirin response (PFA-100 epinephrine closure time)
Time frame: 28-32 weeks gestation
Urinary thromboxane concentration
Time frame: 2-4 weeks after aspirin initiation
Urinary Thromboxane concentration
Time frame: 28-32 weeks gestation
Inadequate aspirin response
Time frame: 2-4 weeks after aspirin initiation
Inadequate aspirin response
Time frame: 28-32 weeks gestation
Preterm birth
Time frame: Delivery
Indicated preterm birth
Time frame: delivery
Spontaneous preterm birth
Time frame: delivery
MicroRNAs
Time frame: 2-4 weeks after aspirin initiation
MicroRNAs
Time frame: 28-32 weeks gestation
Placental histopathology
Time frame: Delivery
Birthweight
Time frame: Delivery
Fetal growth restriction
Time frame: delivery
Hypertensive disorder of pregnancy
Time frame: delivery
Gestational age at delivery
Time frame: Delivery
Pregnancy loss<20 weeks
Time frame: delivery
Fetal demise
Time frame: delivery
Antepartum bleeding
Time frame: Delivery
Abruption
Time frame: delivery
Placental hematoma
Time frame: delivery
Postpartum hemorrhage
Time frame: Delivery
Adherence
Time frame: 2-4 weeks after aspirin
Adherence
Time frame: 28-32 weeks
Neonatal intraventricular hemorrhage Grade II or higher
Time frame: Neonatal discharge
Cordblood serum thromboxane
Time frame: Delivery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jul 2025.
- Individual participant dataSharing planned: Yes. Data will be submitted to NICHD DASH and can be requested through NICHD DASH
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Daily aspirin (ASA) and Split dose aspirin (ASA) in people with Preterm Birth and Preeclampsia, run by Thomas Jefferson University at 1 site in United States.
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 4 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 17 Jul 2025. 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 States. 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.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rupsa C Boelig, MD (215-955-5000, rupsa.boelig@jefferson.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Aspirin Response PFA-100 epinephrine closure time (seconds) (time frame: 2-4 weeks after aspirin initiation). 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 17 Jul 2025; AzTrials last refreshed its copy on 4 Nov 2026.