Aspirin Dose Escalation for the Prevention of Recurrent Preterm Delivery Trial
A Dose Escalation Study of Low Dose Aspirin for the Prevention of Recurrent Preterm Birth
The George Washington University Biostatistics Center
1,800 participants
Jul 1, 2025
INTERVENTIONAL
Conditions
Summary
This is a phase-III multi-center double-blind randomized clinical trial of 1,800 individuals with a history of prior preterm birth at less than 35 weeks gestation who are randomized to either 162 mg aspirin or 81 mg aspirin daily. The study drug will be initiated between 10 and 15 weeks gestation and continued through 36 weeks, 6 days gestation. The primary endpoint is recurrent preterm delivery or fetal death prior to 35 weeks, 0 days gestation.
Eligibility
Inclusion Criteria7
- years or older
- Singleton gestation. Twin gestation reduced to a singleton, either spontaneously or therapeutically, is not eligible unless the reduction occurred before 13 weeks 6 days project gestational age. Higher-order multifetal gestations reduced to singletons are not eligible.
- Gestational age at randomization between 10 weeks 0 days and 15 weeks 6 days based on clinical information and evaluation of the earliest ultrasound.
- Prior preterm birth between 20 weeks 0 days and 34 weeks 6 days with one of the following in the proximal birth reaching 20 weeks or greater:
- Spontaneous preterm birth is defined as spontaneous preterm labor or premature rupture of membranes
- Ischemic placental disease is defined as preeclampsia, small for gestational age, fetal growth restriction, or placental abruption, as defined clinically.
- Stillbirth excluding those with known genetic disorders or major congenital anomalies.
Exclusion Criteria19
- Known allergy or hypersensitivity to aspirin or any medical condition where aspirin is contraindicated (e.g., history of peptic ulcer disease, nasal polyps, NSAID-induced asthma, history of gastrointestinal bleeding, known G6PD deficiency, severe hepatic dysfunction, bleeding disorders, and consumption of 3 or more alcoholic drinks per day)
- Taking other anticoagulants such as Heparin or Low-Molecular weight Heparin
- Thrombocytopenia defined as a platelet count defined as a platelet count <100,000 microliters
- Gastric bypass surgery, regardless of type
- Aspirin use >81 mg daily during the current pregnancy who are not willing or able to go through a 2-week washout before randomization.
- Known major Mullerian anomaly of the uterus (specifically bicornuate, unicornuate, or uterine septum not resected) due to increased risk of preterm delivery.
- Known fetal genetic disease or major malformations
- Fetal demise or planned termination of pregnancy. Selective reduction by 13 weeks 6 days gestation, from twins to singleton, is not an exclusion.
- Any fetal/maternal condition requiring invasive in-utero assessment or treatment, for example, significant red cell antigen sensitization or neonatal alloimmune thrombocytopenia.
- Patients with any of the following medical conditions because of increased risk for adverse pregnancy outcome or indicated preterm birth:
- Treated hypertension requiring more than one agent
- Chronic renal disease with baseline serum creatinine ≥1.5 mg/dL
- Conditions treated with chronic oral glucocorticoid therapy (e.g., systemic lupus erythematosus)
- Uncontrolled hyper- and hypothyroid disease
- New York Heart Association (NYHA) stage II or greater cardiac disease
- Planned indicated delivery prior to 37 weeks.
- Participation in another interventional study that influences the primary outcome in this study (gestational age at delivery).
- Participation in this trial in a previous pregnancy.
- Delivery planned at a non-participating site
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Interventions
Two 81mg aspirin tablets in an over-encapsulated capsule filled with microcrystalline cellulose. Study intervention will be packaged into bottles (35 capsules per bottle).
One 81mg aspirin tablet in an over-encapsulated capsule filled with microcrystalline cellulose. Study intervention will be packaged into bottles (35 capsules per bottle).
Locations(14)
View Full Details on ClinicalTrials.gov
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NCT06980025