Effectiveness of Two Aspirin Doses for Prevention of Hypertensive Disorders of Pregnancy: ASPIRIN TRIAL

Eligibility Criteria

• 1. Live intrauterine gestation \<16 6/7 weeks gestational age based on best obstetric estimate by the American College of Obstetricians and Gynecologists (ACOG) criteria,
• 2. Age 14 years or older and able to provide informed consent,
• 3. At least one of the following high-risk criteria:
• 4. Or two or more moderate-risk criteria for HDP (per The U.S. Preventive Services Task Force (USPSTF)), i) nulliparity (no prior delivery at or after 20 weeks 0 days of gestation) ii) obesity (body mass index ≥30 kg/m2 at time of enrollment) iii) age ≥35 years (at time of expected estimated due date) iv) sociodemographic characteristics (Black race, government-assisted insurance) v) Personal risk factors (previous pregnancy with low birth weight or SGA infant, previous adverse pregnancy outcome \[unexplained stillbirth\], placental abruption, interval \>10 years between pregnancies).
• 1. Known allergy or hypersensitivity to aspirin or any medical condition where aspirin is contraindicated (e.g., active peptic ulcer disease, nasal polyps, NSAID-induced asthma, active gastrointestinal bleeding, known G6PD deficiency, severe hepatic dysfunction, bleeding disorders),
• 2. Planned aspirin use in pregnancy for non-obstetrical indication (e.g., prior stroke/prior myocardial infraction),
• 3. Current aspirin use for obstetrical indications (e.g., related to IVF, or HDP) with inability to enroll and randomize in this trial before 13 0/7 weeks gestation (e.g., aspirin use started at 3 weeks gestation with continued use and approached for participation in this trial at 15 weeks' gestation), or more than 2 weeks of using aspirin if it was started \>13 0/7 weeks (e.g., aspirin started for HDP prevention at 13 0/7 weeks but patient approached for participation at 15 2/7 weeks),
• 4. Age \< 14 years,
• 5. Involuntarily confined or detained,
• 6. Considered as having a diminished decision-making capacity,
• 7. Obstetrical ultrasound suspicious for major congenital abnormality, known or suspected fetal aneuploidy, fetal demise, or planned pregnancy termination,
• 8. Participation in another trial that affects the primary outcome, without prior approval of the PI,
• 9. Plan to delivery outside participating site with inability to obtain medical records,
• 10. Monoamniotic twin gestation because of the risk of fetal demise and preterm delivery,
• 11. Participation in this trial in prior pregnancy,
• 12. Triplet or higher order pregnancy.