Comparison of Doses of Acetylsalicylic Acid in Women With Previous History of Preeclampsia

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2013 by Centre Hospitalier Universitaire de Québec, CHU de Québec
Information provided by (Responsible Party):
Centre Hospitalier Universitaire de Québec, CHU de Québec Identifier:
First received: April 1, 2011
Last updated: May 21, 2013
Last verified: May 2013

Placental insufficiency is the source of preeclampsia (PE) and intrauterine growth retardation (IUGR). Current data demonstrate a significant beneficial effect of prophylactic use of aspirin on the recurrence of placental insufficiency and its complications, mainly preeclampsia, when started early in pregnancy. However, there is a significant heterogeneity in medical practice in Canada and around the world in terms of the dose of aspirin used.

The objectives of this study are: 1) Evaluate whether a dose of 160 mg of aspirin is associated with greater improvement in placental function assessed by biochemistry (sFlt-1 and endoglin) and ultrasound (uterine artery Doppler) than a dose of 80 mg in women with a history of PE, 2) Assess whether the change is dependent on platelet aggregation measured by a test used in several Canadian centers (PFA-100).

Condition Intervention Phase
Fetal Growth Retardation
Prematurity of Fetus
Placental Insufficiency
Drug: Acetylsalicylic acid (ASA) 160 mg
Drug: Acetylsalicylic acid (ASA) 80 mg
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: Evaluation of Dose-response Effect of Acetylsalicylic Acid on Placental Development, Preterm Birth, Fetal Growth and Hypertension in Pregnancy in Women With Previous History of Preeclampsia

Resource links provided by NLM:

Further study details as provided by Centre Hospitalier Universitaire de Québec, CHU de Québec:

Primary Outcome Measures:
  • Placental function [ Time Frame: 22nd week of gestation ] [ Designated as safety issue: No ]
    We chose a continuous intermediate variable focused on the aetiology, the placental function, assessed by Doppler ultrasound: the average pulsatility index of uterine arteries (UTAP - primary outcome) at 22 weeks of gestation

Secondary Outcome Measures:
  • Rates of pregnancy complications related to placental insufficiency (preeclampsia, IUGR, premature birth) [ Time Frame: At delivery ] [ Designated as safety issue: No ]
    The effectiveness of treatment on the rate of preterm delivery, hypertensive disorders of pregnancy and IUGR will also be measured by reviewing medical records. All cases with a diagnosis of preterm labor, gestational hypertension or IUGR <10th percentile will be reviewed by a specialist in maternal fetal medicine at blindness for allocation.

Estimated Enrollment: 104
Study Start Date: September 2011
Estimated Study Completion Date: June 2014
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Group A-160
Pregnant women with previous PE taking 160 mg of acetylsalicylic acid once a day at bedtime
Drug: Acetylsalicylic acid (ASA) 160 mg
Other Names:
  • Asaphen
  • Aspirin
Active Comparator: Group B-80
Pregnant women with previous PE taking 80 mg of acetylsalicylic acid once a day at bedtime
Drug: Acetylsalicylic acid (ASA) 80 mg
Other Names:
  • Asaphen
  • Aspirin

Detailed Description:

Many studies suggest that aspirin (acetylsalicylic acid) at low dose significantly reduces the incidence of preeclampsia. More recent data have shown that, when administered before 16 weeks of pregnancy, aspirin can prevent over 50% of preeclampsia, severe preeclampsia, and IUGR but also a significant proportion of the rate of preterm births. Current data also demonstrate a beneficial effect of prophylactic use of aspirin when started early in pregnancy in populations composed of high-risk patients with a history of preeclampsia and / or other pregnancy complications related to poor placental function.

Beside, many clinicians are already using aspirin in the context of a proven benefit. However, the usual dose prescribed in Canada today is 80 mg while the most favorable studies have used a slightly higher dose of aspirin (100 mg).

Moreover, it has been demonstrated that the time of day during which aspirin was administered was also a very important factor regarding the effect on blood pressure and adverse outcomes of the majority of pregnancy. Yet the majority of studies in this context have not specified the time of day at which aspirin was or had been taken, possibly underestimating the effect thereof.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Gestational age between 10 0 / 7 and 13 6 / 7 weeks
  • History of preeclampsia (as defined by The Society of Obstetricians and Gynaecologists of Canada [SOGC]) confirmed by medical records

Exclusion Criteria:

  • Negative Fetal Heart
  • Multiple pregnancy
  • Anaphylactic allergy to lactose
  • Kown coagulopathy (antithrombin III deficiency, factor V Leiden, antiphospholipid syndrome, the prothrombin mutation, deficiency of protein S or protein C)
  • Use of heparin or other anticoagulants.
  • Contraindications to aspirin
  • Severe fetal abnormality (cystic hygroma, nuchal translucency> 95th percentile, anencephaly, etc.)
  • History or active peptic ulcer
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01352234

Contact: Sylvie Tapp, BSc 418 525 4444 ext 46039

Canada, Quebec
Centre Hospitalier Universitaire de Québec (CHUQ)/Pavillon CHUL Recruiting
Québec, Quebec, Canada, G1V 4G2
Principal Investigator: Emmanuel Bujold, MD, MSc         
Sub-Investigator: Sylvie Tapp, MSc         
Sub-Investigator: Yves Giguère, MD PhD         
Sub-Investigator: Emma Feirrera, BPharm MSc         
Sub-Investigator: Grégoire Leclerc, BPharm PhD         
Sub-Investigator: Nils Chaillet, PhD         
Sub-Investigator: Katy Gouin, MD         
Sponsors and Collaborators
Centre Hospitalier Universitaire de Québec, CHU de Québec
Principal Investigator: Emmanuel Bujold, MD, MSc Centre Hospitalier Universitaire de Québec, CHU de Québec
  More Information

No publications provided

Responsible Party: Centre Hospitalier Universitaire de Québec, CHU de Québec Identifier: NCT01352234     History of Changes
Other Study ID Numbers: C10-11-108
Study First Received: April 1, 2011
Last Updated: May 21, 2013
Health Authority: Canada: Health Canada

Additional relevant MeSH terms:
Fetal Diseases
Fetal Growth Retardation
Placental Insufficiency
Hypertension, Pregnancy-Induced
Pregnancy Complications
Growth Disorders
Pathologic Processes
Placenta Diseases
Vascular Diseases
Cardiovascular Diseases
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Pharmacologic Actions
Anti-Inflammatory Agents
Therapeutic Uses
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Cardiovascular Agents
Hematologic Agents
Platelet Aggregation Inhibitors processed this record on July 09, 2014