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Not yet recruitingNCT07665853Optim-PREUpdated Jun 24, 2026

Optimizing the Use of Aspirin for the Prevention of Preeclampsia

A Phase 3 interventional study of Discontinuation of Acetylsalicilic acid 150 mg/day at 24-28 weeks of gestation in Preeclampsia, sponsored by Hospital Universitari Vall d'Hebron Research Institute. Not yet recruiting at 38 sites in 7 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-24.

Sponsored by Hospital Universitari Vall d'Hebron Research Institute · Phase 3, Interventional, and Prevention

Phase
Phase 3
Study type
Interventional
Enrollment
15,160
Allocation
Randomized
Ages
18 Years and older
Sex
Female
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Study summary

Pregnant women at higher risk for preeclampsia (PE) are currently recommended to take low-dose aspirin (acetylsalicylic acid, ASA) daily from the first trimester until 36 weeks of gestation. High-risk women are identified through a multiparametric first-trimester screening that combines maternal history, blood pressure, uterine artery blood flow, and placental growth factor (PlGF). Although this screening effectively identifies women at risk, the majority of those classified as high risk will not develop PE. As a result, a large proportion of pregnant women receive prolonged aspirin treatment without benefit, while remaining exposed to its potential side effects, including increased bleeding risk.

Aspirin prevents PE primarily by improving placental development during the first half of pregnancy. Whether continuing ASA beyond 24-28 weeks provides additional protection remains unclear. A previous randomized trial demonstrated that stopping ASA at 24-28 weeks was non-inferior to continuing until 36 weeks in a predominantly European population. However, whether this finding applies to more diverse populations, including women of African origin who carry a substantially higher baseline risk of PE, has not been established.

This is a multicenter, randomized, open-label, parallel-group, phase III non-inferiority trial conducted across sites in Europe and Africa. A total of 15,160 pregnant women at high risk for PE from first-trimester screening, currently under ASA treatment, will be randomized in a 1:1 ratio before 28 weeks of gestation to either discontinue ASA at 24-28 weeks or continue ASA until 36 weeks of gestation.

Read the detailed description

The primary objective of the study is to demonstrate that in pregnant women at high risk for preeclampsia from first-trimester multiparametric screening, the incidence of preterm PE after discontinuation of ASA at 24-28 weeks of gestation is non-inferior to that of the control group, who continue ASA until 36 weeks.

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Conditions studied

  • Preeclampsia

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Keywords

  • Preeclampsia
  • First Trimester Screening
  • Placental Growth Factor
  • Ophthalmic Artery Doppler
  • Acetyl Salicylic Acid (ASA)
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Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  • Age 18 years or older at time of enrollment.
  • Singleton pregnancy.
  • Ability to read and understand the informed consent form.
  • Having undergone first-trimester preeclampsia screening between 11+0 and 13+6 weeks of gestation using a validated multiparametric algorithm (FMF algorithm at a risk cutoff of 1:100, or Gaussian algorithm at a cutoff of 1:170) and being classified as high risk for preterm preeclampsia.
  • Currently taking aspirin 150 mg/day initiated after first-trimester high-risk classification, in accordance with standard clinical practice.
  • Voluntary signing of the informed consent form and willingness to comply with the study requirements, including acceptance of the assigned aspirin treatment duration, additional blood tests, and additional ultrasound assessments.

Exclusion criteria

Exclusion Criteria:

  • Early pregnancy loss, intrauterine fetal death, or fetus with major structural malformations diagnosed at the time of enrollment.
  • Fetus affected by a known genetic or chromosomal disease.
  • Contraindication, allergy, or intolerance to aspirin (acetylsalicylic acid).
  • Any medical condition that makes aspirin discontinuation unsafe or impossible (e.g., antiphospholipid syndrome, mechanical heart valve, or other conditions requiring indefinite antiplatelet or anticoagulant therapy).
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Study design

Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
15,160 participants (estimated)

Study arms

  • Experimental
    ASA withdrawn group

    ASA is discontinued at 24-28 weeks of gestation

    Drug: Discontinuation of Acetylsalicilic acid 150 mg/day at 24-28 weeks of gestation

  • No intervention
    Continue ASA Group

    ASA is continued until 36 weeks of gestation

Interventions

  • DrugDiscontinuation of Acetylsalicilic acid 150 mg/day at 24-28 weeks of gestation

    Intervention group will discontinuate of Acetyl Salicylic acid at 24-28 weeks of gestation while Control Group will continue Acetyl Salicylic acid 150 mg/day until 36 weeks of gestation.

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What researchers measure

Primary outcomes

  1. Rate of preterm preeclampsia in both arms of the study (ASA vs no ASA).

    Rate of pre-eclampsia \<37 weeks in pregnant women at high-risk for early-onset PE from the first-trimester screening in both arms of the study (ASA vs no ASA).

    Time frame: From 20 weeks of gestation onwards

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Study locations

38 sites
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References and documents

Individual participant data

Plan to share: Yes — Upon publication, anonymized data will be deposited in the VHIR's institutional open research data repository.

No publications or documents are linked to this record.

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Registry details

Key details

Study ID
NCT07665853
Lead sponsor
Hospital Universitari Vall d'Hebron Research Institute
Collaborators
Fetal Medicine Foundation
Responsible party
Sponsor
First posted
Jun 24, 2026
Start date
Jul 1, 2026 (estimated)
Primary completion
May 2028 (estimated)
Completion
May 2028 (estimated)
Last update
Jun 24, 2026

Study contacts

Manel Mendoza Cobaleda, Professor
Contact
manel.mendoza@vallhebron.cat
+34 93 489 30 00 ext. 6548
Manel Mendoza Cobaleda, Professor
principal investigator · Hospital Universitari Vall Hebron - Vall Hebrón Institut de Recerca
Kypros Nicolaides, Professor
principal investigator · Fetal Medicine Foundation

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.

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