Optimizing the Use of Aspirin for the Prevention of Preeclampsia
Optim-PRE
5 other identifiers
interventional
15,160
7 countries
38
Brief 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_3
Started Jul 2026
38 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
June 18, 2026
CompletedFirst Posted
Study publicly available on registry
June 24, 2026
CompletedStudy Start
First participant enrolled
July 1, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
May 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
May 1, 2028
June 24, 2026
June 1, 2026
1.8 years
June 18, 2026
June 18, 2026
Conditions
Keywords
Outcome Measures
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).
From 20 weeks of gestation onwards
Study Arms (2)
ASA withdrawn group
EXPERIMENTALASA is discontinued at 24-28 weeks of gestation
Continue ASA Group
NO INTERVENTIONASA is continued until 36 weeks of gestation
Interventions
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.
Eligibility Criteria
You may qualify if:
- 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.
You may not qualify if:
- 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).
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (38)
Medical University of Vienna
Vienna, Austria
St Josef Hospital
Vienna, Austria
Dr Shterev Hospital
Sofia, Bulgaria
Saint Patrick Hospital
Ofinso, Ghana
Holy Family Hospital
Techiman, Ghana
Hopital Phillipe Senghor
Dakar, Senegal
Centre Hospitalier Régional de Saint-Louis
Saint-Louis, Senegal
Hospital San Cecilio
Granada, Andalusia, Spain
Hospital Universitari Dexeus
Barcelona, BARCELONA, 08024, Spain
Hospital Dr.Josep Trueta
Girona, Girona, 17007, Spain
Hospital Joan XXIII
Tarragona, Tarragona, 43007, Spain
Hospital de Cruces
Barakaldo, Vizcaya, 48903, Spain
Complejo Hospitalario Universitario de A Coruña
A Coruña, Spain
Hospital General de Alicante
Alicante, Spain
Hospital Universitari Vall d'Hebron
Barcelona, 08035, Spain
Hospital de la Santa Creu i Sant Pau
Barcelona, Spain
Hospital Universitari Vall d'Hebrón
Barcelona, Spain
Hospital Universitario de Burgos
Burgos, Spain
Hospital Universitario Puerta del Mar
Cadiz, Spain
Hospital Universitario Virgen de las Nieve
Granada, Spain
Hospital Universitario de Jerez
Jerez de la Frontera, Spain
Hospital Materno Infantil de Gran Canaria
Las Palmas de Gran Canaria, Spain
Hospital Universitario Severo Ochoa
Leganés, Spain
Hospital de León
León, Spain
Hospital Arnau de Vilanova de Lleida
Lleida, Spain
Fundación Jiménez Díaz
Madrid, Spain
Hospital Universitario Rey Juan Carlos
Móstoles, Spain
Hospital Clínico Universitario Virgen de la Arrixaca
Murcia, Spain
Clínica Universidad de Navarra
Pamplona, Spain
Hospital Universitario de Canarias
San Cristóbal de La Laguna, Spain
Hospital Universitario Nuestra Señora de Candelaria
Santa Cruz de Tenerife, Spain
Consorci Sanitari de Terrassa
Terrassa, Spain
Hospital Universitari Mútua Terrassa
Terrassa, Spain
Hospital Universitario de Torrejón
Torrejón de Ardoz, Spain
Bundung Maternal and Child Health Hospital
Banjul, The Gambia
Brikama District Hospital
Brikama, The Gambia
King's College Hospital
London, United Kingdom
Medway Maritime Hospital
London, United Kingdom
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Manel Mendoza Cobaleda, Professor
Hospital Universitari Vall Hebron - Vall Hebrón Institut de Recerca
- PRINCIPAL INVESTIGATOR
Kypros Nicolaides, Professor
Fetal Medicine Foundation
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
June 18, 2026
First Posted
June 24, 2026
Study Start
July 1, 2026
Primary Completion (Estimated)
May 1, 2028
Study Completion (Estimated)
May 1, 2028
Last Updated
June 24, 2026
Record last verified: 2026-06
Data Sharing
- IPD Sharing
- Will share
Upon publication, anonymized data will be deposited in the VHIR's institutional open research data repository.