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PreeclampsiaPhase 3ASAPPNCT04070573

Low Doses of Aspirin in the Prevention of Preeclampsia

A Phase 3 study testing acetylsalicylic acid in people with Preeclampsia, run by Weill Medical College of Cornell University at 2 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Preeclampsia (PE) is a morbid and potentially lethal complication of pregnancy and is more common in women with specific risk factors. Aspirin (ASA) is currently the only prophylactic therapy for preeclampsia in high-risk women to be recognized by the US Preventive Task Force and should be initiated early in the… Read more about this study

Who is it for?
Ages 18 to 60 years, women only
Conditions the study is for
Preeclampsia
What is being tested?
acetylsalicylic acid
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
400 participants
Where
2 sitesUnited States
Study dates
21 Oct 2019to 23 Jan 2025
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 to 60 years
  • Women only
  • No healthy volunteers
  • Adult

Who may be able to join

  • Pregnant patients, ≥18 years old, at less than 16 weeks' gestation (as documented by ultrasound) with at least one of the following risk factors for developing PE:
  • PE in a prior pregnancy
  • Chronic hypertension (prior to pregnancy or before 20 weeks' gestation)
  • Type 1 or 2 diabetes
  • Renal disease (proteinuria ≥300mg/day or estimated GFR<90mL/min/1.73 m2)
  • Multifetal gestation
  • Autoimmune disease (e.g. systemic lupus erythematous, antiphospholipid syndrome)

Who cannot join

  • Patient with known intention to terminate pregnancy
  • Major fetal malformation seen on ultrasound
  • Contraindication to ASA therapy (including but not limited to allergy and high bleeding risk)

Trial locations and contacts

2 sites in 1 country.

United States2 sites
  • New York Presbyterian - Weill Cornell

    New York, New York, 10065

  • New York Presbyterian Queens

    New York, New York, 11355

Other trials in United States

About this study

Official title: A Randomized Controlled Trial Comparing Low Doses Of Aspirin In The Prevention Of Preeclampsia (ASAPP)

Preeclampsia (PE) is a morbid and potentially lethal complication of pregnancy and is more common in women with specific risk factors. Aspirin (ASA) is currently the only prophylactic therapy for preeclampsia in high-risk women to be recognized by the US Preventive Task Force and should be initiated early in the second trimester of pregnancy, before 16 weeks of gestation. However, currently there is no literature comparing various low-dose ASA formulations in the risk reduction of PE. In the United States, the currently available low-dose ASA is over the counter and is found in 81mg tablets. Therefore, when clinicians initiate therapy with low dose ASA, they may prescribe 1 or 2 tablets of 81mg aspirin per day depending on personal preference and cannot be assisted by evidence to guide their decision.This study aims to determine the incidence of preterm PE or PE with severe features in women taking either 81mg or 162mg in a randomized setting, from a single center. The investigators hypothesize that the information gained from this trial will permit a more accurate sample size calculation for a larger clinical trial powered to accept or reject our testing hypothesis. If our hypothesis is rejected and 162mg of daily ASA is not associated with a lower incidence of severe or preterm PE compared to 81mg, this may be due to lack of power to detect a smaller effect. The investigators would then evaluate the feasibility and results and determine whether a larger trial is reasonable.

Read the detailed description

Preeclampsia (PE) is a serious and potentially fatal complication of pregnancy. It is a placental disease characterized by an elevated blood pressure in the 3rd trimester with multisystem involvement (proteinuria, elevated liver enzymes, low platelet count and/or neurologic symptoms). PE can cause pulmonary edema, seizures, or stroke and is a leading cause of maternal mortality. The pregnancy outcomes are further worsened if PE develops before term. Women who have a history of PE in a prior pregnancy, diabetes, preexisting hypertension, kidney disease, multifetal gestation or autoimmune diseases are at an increased risk to develop PE in a subsequent pregnancy.

Clinical trials evaluating the benefits of low-dose aspirin (ASA) have used a wide range of doses from 60mg to 150mg orally daily with low-dose being defined as less than 325mg per day. Taking ASA (as opposed to placebo) is thought to reduce the risk of preeclampsia by 17%, without increasing the risk of major obstetric bleeding. The number needed to treat is only 19 women. ASA is currently the only prophylactic therapy for PE in high-risk women to be recognized by the US Preventive Task Force and should be initiated early in the second trimester of pregnancy, before 16 weeks of gestation.

There has also been more awareness that the efficacy of ASA in preventing preeclampsia is limited by the poor adherence of patients to this therapy. Indeed, a cross-sectional study has estimated that up to 46% of women (n=42) on ASA therapy may not be compliant to it, as determined by a validated Simplified Medication Adherence Questionnaire (SMAQ). Adherence is essential to the efficacy of ASA in preventing preterm preeclampsia. It would therefore be of interest to obtain more information about adherence to ASA in women who need this therapy.

Assessing molecular pathways in the development of PE may allow opportunity for earlier diagnosis, specific triaging of patients to closer monitoring and further development of preventative or curative treatment strategies. Samples will be biobanked for biomarker discovery in the future.

The current literature is lacking in evidence to recommend a specific daily dose of ASA. Recent meta-analyses have suggested that there may be a dose response in the protective effect of ASA for PE. As compared to 60mg per day, an ASA dose of 100mg per day was associated with a lower relative risk of PE (0.44 vs 0.57, p=0.36). A large study of 1776 women has compared a slightly higher dose of ASA (150mg per day) to placebo and found a decrease in preterm delivery (before 37 weeks) due to PE (OR 0.38, p=0.004). Meta-analyses have shown that any dose of ASA above 60mg per day is protective and should be used to prevent PE in high risk pregnancies.

To date, there has not been any studies comparing lower doses of ASA (such as 81mg, the traditional "baby aspirin" dose sold in the US) to higher "low-dose" ASA regimens (such as 162mg) in their ability to prevent preterm or severe PE in women who are at a high risk for this devastating disease.

Conditions
Preeclampsia
Being tested
acetylsalicylic acid
Keywords
Preterm preeclampsia, Preeclampsia with severe features, High risk pregnancy, Low dose aspirin, Cell free RNA, Compliance
Medical subject headings
Pre-Eclampsia, Patient Compliance

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • acetylsalicylic acidDrug

    Also called aspirin, ASA

    High risk pregnant women will be treated with daily aspirin during pregnancy.

Study groups in NCT04070573
Study groupRoleWhat they receive
81mg ASAActive comparatorPatients in Arm 1, will be instructed to take one tablet of 81mg aspirin per day.
Receives: Drug: acetylsalicylic acid
162mg ASAActive comparatorPatients in Arm 2, will be instructed to take two tablets simultaneously orally once per day.
Receives: Drug: acetylsalicylic acid

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of Preterm (<37 Weeks) Preeclampsia

    The incidence of preterm (<37 weeks) preeclampsia in high risk pregnant women treated with either 81 mg or 162 mg of daily aspirin during pregnancy.

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

  2. Incidence of Preeclampsia With Severe Features

    The incidence of preeclampsia with severe features (American College of Obstetricians and Gynecologists 2019 definition) in high-risk pregnant women treated with either 81 mg or 162 mg of daily aspirin during pregnancy.

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

  3. Composite Primary Outcome

    Composite of preterm preeclampsia and/or preeclampsia with severe features

    Measured: 9 months for each participant

Secondary outcomes (4)
  1. Aspirin Adherence

    Evaluate and compare the adherence of pregnant women to 81mg and 162mg of daily low-dose aspirin using a validated, Simplified Medication Adherence Questionnaire (SMAQ).

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

  2. Maternal and Fetal Outcomes

    Compare maternal and fetal outcomes in pregnant women at a high risk for preeclampsia who are treated with either 81mg or 162mg of daily aspirin during pregnancy, including gestational hypertension, postpartum hypertension, preterm delivery <37 weeks, fetal growth restriction (IUGR) or low birthweight (<2000g), placental abruption, ICU admission (maternal and neonatal), and maternal/fetal mortality.

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

  3. Time-to-event for Preeclampsia: Gestational Age at Onset of Preeclampsia

    Compare the time-to-event for developing preeclampsia for women treated with 81mg vs 162mg of aspirin per day. The time to event analysis will be made using the gestational age at the onset of preeclampsia as a variable

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

  4. Aspirin Adherence- All Time Points Together

    To assess the adherence to low dose aspirin in pregnant women that are at high risk for preeclampsia and compare compliance rates for women on 81mg vs 162mg of aspirin per day using urine studies for salicylates and serum analysis. All time points together

    Measured: 9 months for each patient (from recruitment until 6 weeks postpartum)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Aug 2019
  2. Study start21 Oct 2019
  3. Primary completion4 Mar 2024
  4. Study completion23 Jan 2025

Resources

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 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Arm 1: 81mg oral ASA daily. Arm 2: 162mg oral ASA daily. Patients will obtain their prescriptions from their respective pharmacies. Women in Arm 1, will be instructed to take one table of 81mg aspirin per day; those in Arm 2, will be asked to take two tablets simultaneously orally once per day. Therapy will be initiated at the baseline visit and continued until 1 week before planned delivery or upon admission for unplanned/imminent delivery as per clinical routine.
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
400 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04070573
Sponsor's protocol ID
19-05020160
Acronym
ASAPP
Status last verified
Feb 2025
First submitted
23 Aug 2019
Last updated
13 Mar 2025
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • ACOG Practice Bulletin No. 202: Gestational Hypertension and Preeclampsia. Obstet Gynecol. 2019 Jan;133(1):1. doi: 10.1097/AOG.0000000000003018.

    PubMed 30575675
  • Lisonkova S, Joseph KS. Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease. Am J Obstet Gynecol. 2013 Dec;209(6):544.e1-544.e12. doi: 10.1016/j.ajog.2013.08.019. Epub 2013 Aug 22.

    PubMed 23973398
  • Duley L, Henderson-Smart DJ, Meher S, King JF. Antiplatelet agents for preventing pre-eclampsia and its complications. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD004659. doi: 10.1002/14651858.CD004659.pub2.

    PubMed 17443552
  • Henderson JT, Whitlock EP, O'Conner E, Senger CA, Thompson JH, Rowland MG. Low-Dose Aspirin for the Prevention of Morbidity and Mortality From Preeclampsia: A Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2014 Apr. Report No.: 14-05207-EF-1. Available from http://www.ncbi.nlm.nih.gov/books/NBK196392/

    PubMed 24783270
  • Abheiden CN, van Reuler AV, Fuijkschot WW, de Vries JI, Thijs A, de Boer MA. Aspirin adherence during high-risk pregnancies, a questionnaire study. Pregnancy Hypertens. 2016 Oct;6(4):350-355. doi: 10.1016/j.preghy.2016.08.232. Epub 2016 Aug 6.

    PubMed 27939481
  • Wright D, Poon LC, Rolnik DL, Syngelaki A, Delgado JL, Vojtassakova D, de Alvarado M, Kapeti E, Rehal A, Pazos A, Carbone IF, Dutemeyer V, Plasencia W, Papantoniou N, Nicolaides KH. Aspirin for Evidence-Based Preeclampsia Prevention trial: influence of compliance on beneficial effect of aspirin in prevention of preterm preeclampsia. Am J Obstet Gynecol. 2017 Dec;217(6):685.e1-685.e5. doi: 10.1016/j.ajog.2017.08.110. Epub 2017 Sep 6.

    PubMed 28888591
  • Shanmugalingam R, Hennessy A, Makris A. Aspirin in the prevention of preeclampsia: the conundrum of how, who and when. J Hum Hypertens. 2019 Jan;33(1):1-9. doi: 10.1038/s41371-018-0113-7. Epub 2018 Sep 19.

    PubMed 30232399
  • Ngo TTM, Moufarrej MN, Rasmussen MH, Camunas-Soler J, Pan W, Okamoto J, Neff NF, Liu K, Wong RJ, Downes K, Tibshirani R, Shaw GM, Skotte L, Stevenson DK, Biggio JR, Elovitz MA, Melbye M, Quake SR. Noninvasive blood tests for fetal development predict gestational age and preterm delivery. Science. 2018 Jun 8;360(6393):1133-1136. doi: 10.1126/science.aar3819.

    PubMed 29880692
  • Koh W, Pan W, Gawad C, Fan HC, Kerchner GA, Wyss-Coray T, Blumenfeld YJ, El-Sayed YY, Quake SR. Noninvasive in vivo monitoring of tissue-specific global gene expression in humans. Proc Natl Acad Sci U S A. 2014 May 20;111(20):7361-6. doi: 10.1073/pnas.1405528111. Epub 2014 May 5.

    PubMed 24799715
  • Roberge S, Nicolaides K, Demers S, Hyett J, Chaillet N, Bujold E. The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction: systematic review and meta-analysis. Am J Obstet Gynecol. 2017 Feb;216(2):110-120.e6. doi: 10.1016/j.ajog.2016.09.076. Epub 2016 Sep 15.

    PubMed 27640943
  • Seidler AL, Askie L, Ray JG. Optimal aspirin dosing for preeclampsia prevention. Am J Obstet Gynecol. 2018 Jul;219(1):117-118. doi: 10.1016/j.ajog.2018.03.018. Epub 2018 Mar 26. No abstract available.

    PubMed 29588190
  • Rolnik DL, Wright D, Poon LC, O'Gorman N, Syngelaki A, de Paco Matallana C, Akolekar R, Cicero S, Janga D, Singh M, Molina FS, Persico N, Jani JC, Plasencia W, Papaioannou G, Tenenbaum-Gavish K, Meiri H, Gizurarson S, Maclagan K, Nicolaides KH. Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia. N Engl J Med. 2017 Aug 17;377(7):613-622. doi: 10.1056/NEJMoa1704559. Epub 2017 Jun 28.

    PubMed 28657417
  • Perneby C, Vahter M, Akesson A, Bremme K, Hjemdahl P. Thromboxane metabolite excretion during pregnancy--influence of preeclampsia and aspirin treatment. Thromb Res. 2011 Jun;127(6):605-6. doi: 10.1016/j.thromres.2011.01.005. Epub 2011 Feb 12. No abstract available.

    PubMed 21316743
  • Vainio M, Riutta A, Koivisto AM, Maenpaa J. Prostacyclin, thromboxane A and the effect of low-dose ASA in pregnancies at high risk for hypertensive disorders. Acta Obstet Gynecol Scand. 2004 Dec;83(12):1119-23. doi: 10.1111/j.0001-6349.2004.00396.x.

    PubMed 15548142
  • American College of Obstetricians and Gynecologists' Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 203: Chronic Hypertension in Pregnancy. Obstet Gynecol. 2019 Jan;133(1):e26-e50. doi: 10.1097/AOG.0000000000003020.

    PubMed 30575676

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing acetylsalicylic acid in people with Preeclampsia, run by Weill Medical College of Cornell University at 2 sites 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 7 inclusion and 3 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 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites 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 phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 13 Mar 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Incidence of Preterm (<37 Weeks) Preeclampsia (time frame: 9 months for each patient (from recruitment until 6 weeks postpartum)). The study lists 3 primary outcomes in all. 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 NCT04070573, which also lists 18 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 Mar 2025.

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