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

This study has been completed.
Information provided by (Responsible Party):
Centre Hospitalier Universitaire de Québec, CHU de Québec Identifier:
First received: April 1, 2011
Last updated: December 13, 2016
Last verified: July 2014

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
Premature Birth
Placental Insufficiency
Drug: Acetylsalicylic Acid
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
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 ]
    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 ]
    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.

Enrollment: 104
Study Start Date: September 2011
Study Completion Date: March 2015
Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Group A
Acetylsalicylic Acid 160mg administered at bedtime
Drug: Acetylsalicylic Acid
Capsule containing Acetylsalicylic Acid 160mg pill with lactose
Other Names:
  • Asaphen
  • Aspirin
  • ASA
Active Comparator: Group B
Acetylsalicylic Acid 80mg administered at bedtime
Drug: Acetylsalicylic Acid
Capsule containing Acetylsalicylic Acid 80mg pill with lactose
Other Names:
  • Asaphen
  • Aspirin
  • ASA

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   (Adult, Senior)
Sexes 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) 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
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Please refer to this study by its identifier: NCT01352234

Canada, Quebec
Centre Hospitalier Universitaire de Québec (CHUQ)/Pavillon CHUL
Québec, Quebec, Canada, G1V 4G2
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

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: December 13, 2016
Individual Participant Data  
Plan to Share IPD: Undecided

Additional relevant MeSH terms:
Premature Birth
Placental Insufficiency
Fetal Growth Retardation
Hypertension, Pregnancy-Induced
Pregnancy Complications
Obstetric Labor, Premature
Obstetric Labor Complications
Placenta Diseases
Fetal Diseases
Growth Disorders
Pathologic Processes
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Antipyretics processed this record on April 24, 2017