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

Open to females ages 14-35

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:

   i) any prior pregnancy complicated by preeclampsia ii) current pregnancy complicated by chronic hypertension diagnosed before randomization (ACOG) iii) pre-gestational diabetes (on medication for diabetes prior to pregnancy, or diabetes is diagnosed prior to randomization with hemoglobin A1C of 6.5% or greater or elevated 3-hour glucose tolerance test) iv) twin gestation (including higher order pregnancy reduced to twins prior to 14 weeks) v) chronic kidney disease vi) autoimmune disease (e.g., antiphospholipid syndrome, lupus)

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.