Effect of Low Dose Aspirin on Birthweight in Twins: The GAP Trial.

Study Overview
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Brief Summary
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Low-dose aspirin started in the first-trimester has been associated with a decrease of preeclampsia, fetal growth restriction and preterm birth in high-risk pregnancies. Multiple pregnancies are considered a risk factor for all those adverse outcomes. The main objective of the current trial is to evaluate whether a dose of 80 mg of aspirin is associated with an improvement of birthweight compared to placebo in twin pregnancies.

Detailed Description
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Twin pregnancies represent approximately 3% of births and are associated with increased risks of complications such as preeclampsia, fetal growth restriction and preterm birth. All of these complications are commonly associated impaired placental function and low birth weight. Most prophylactic measures tested over the years have failed to prevent these adverse outcomes in twin pregnancies. Since administration of low-dose of aspirin can improve placental function and all these adverse outcomes in high-risk pregnancies, mainly in women with prior adverse outcomes, we suggest that similar benefits could be seen in twins. We are expecting that the administration of low-dose of aspirin starting in the first-trimester in twin pregnancies could lead to an improvement of placental function, a reduction or these adverse perinatal outcomes and therefore to an improvement of birthweight.

Official Title
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Effect of Low Dose Aspirin on Birthweight in Twins: The GAP Trial

Conditions
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Small for Gestational Age, Infant, Very Low Birth Weight, Fetal Growth Retardation, Preeclampsia, Premature Birth

Intervention / Treatment
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* Drug: Acetylsalicylic Acid
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Gestational age between 8 0/7 and 13 6/7 weeks Twin pregnancy confirmed by ultrasound Exclusion Criteria: One or two negative heart beat Previous hypertensive disorder of pregnancy Pre-existing hypertension or diastolic blood pressure >90 mmHg at randomization Pre-existing nephropathy Pre-existing diabetes (type 1 or 2) Anaphylactic allergy to lactose Known 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. Contre-indications to aspirin Discordance of crown-rump length greater than 20%. Fetal anomalies (cystic hygroma, nuchal translucency > 95th percentile, anencephaly, omphalocele, etc.) Previous or current gastric ulcer

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Experimental<br>Acetylsalicylic Acid 80mg administered daily at bedtime | Drug: Acetylsalicylic Acid<br>* Capsule containing Acetylsalicylic Acid 80mg pill with lactose<br>* Other names: Asaphen;|
| Placebo Comparator: Control<br>Identical placebo administered daily at bedtime | Drug: Placebo<br>* Capsule containing placebo pill with lactose<br>* Other names: Control;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Birth weight |  | At delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Low birth weight | (birthweight below 2,500 grams) | At delivery | 
| Very low birth weight | (birthweight below 1,500 grams) | At birth | 
| Fetal growth restriction | (birthweight below the 10th or 3rd percentile for gestational age) | 16-18 and 22-24 weeks | 
| Preterm birth | (delivery before 37 weeks) | At delivery | 
| Very preterm birth | (delivery before 34 weeks) | At delivery | 
| Preeclampsia | (according to American College of Obstetricians and Gynecologists 2014 guidelines definition) | At delivery | 
| Early-onset preeclampsia | (onset of preeclampsia before 34 weeks) | At delivery | 
| UtA_PI | Mean uterine artery pulsatility index | 22-24 weeks | 
| Aspirin resistance | (PFA-100 below 150) | 16-18 and 22-24 weeks | 
| Cervical length |  | 22-24 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Twin Pregnancy, Pregnancy Complications