AspirinEV Based Platform for Monitoring Therapeutics Response During Pregnancy (ARISE)

Inclusion Criteria:

Participants will be eligible to participate if they meet the following study inclusion criteria:

1. pregnant individuals age ≥18 years
2. enrolled ≤16 6/7 weeks of gestation based on the best obstetric estimate as defined by ACOG criteria
3. singleton live intrauterine gestation
4. Any of the following:

1. At least one of the high-risk criteria for HDP (per US Preventive Services Task Force Recommendation Statement \[USPSTF\]); i) any prior pregnancy complicated by Preeclampsia ii) current pregnancy complicated by chronic hypertension iii) chronic kidney disease iv) autoimmune disease (e.g., antiphospholipid syndrome, lupus) or
2. Two or more moderate-risk criteria for HDP (per 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) Black race v) Low income vi) 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).

vii) Pregnancy after in vitro conception viii) family history of preeclampsia ( i.e., mother or sister)
3. or participating in another clinical RCT of 81mg vs. 162mg aspirin for prevention of hypertensive disorders of pregnancy

Exclusion Criteria:

1. age < 18 years,
2. involuntarily confined or detained
3. considered as having a diminished decision-making capacity
4. multifetal gestation
5. pregestational diabetes mellitus or gestational diabetes diagnosed < 20 weeks due to the impact on exosome response
6. known or suspected fetal aneuploidy or major congenital abnormality, fetal demise, or planned pregnancy termination
7. known allergy or hypersensitivity to aspirin or any medical condition where aspirin is contraindicated (e.g., peptic ulcer disease, nasal polyps, NSAID-induced asthma, gastrointestinal bleeding, G6PD deficiency, severe hepatic dysfunction, bleeding disorders)
8. plan to deliver at another center or participating in another intervention study that influences the primary outcome in this study, without prior approval