RecruitingPhase 4Drug trialEffectiveness of Two Aspirin Doses for Prevention of Hypertensive Disorders of Pregnancy: ASPIRIN TRIALThe overall goal of this large, pragmatic, comparative effectiveness trial is to test the hypothesis that among at-risk individuals, 162 mg/day aspirin is superior to 81 mg/day in preventing Hypertensive disorders of pregnancy (HDP), and that there are multiple factors associated with adherence with aspirin therapy that will be important to identify to enable optimal implementation of study findings and population-level benefits.