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

Hypertensive disorders of pregnancy (HDP), such as preeclampsia (PE) and gestational hypertension (gHTN), occur in \~15% of pregnant individuals, disproportionately affect self-identified non-Hispanic Black individuals (with the understanding that race is a socially defined construct and the inequity is related to social determinants of health), are increasing in frequency, and are associated with short- and long-term maternal and neonatal morbidities and mortality. There are currently no available therapeutics to treat individuals with HDP; thus, developing interventions for the prevention of HDP is of substantial public health significance. The U.S. Preventive Services Task Force (USPSTF) and other professional societies recommend or endorse the use of aspirin for prevention of HDP in individuals at high or moderate risk. However, there is great uncertainty regarding optimal dosing, whether there is heterogeneity of effectiveness of aspirin in reducing the risk of HDP among different populations, and what factors are associated with adherence. The 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 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. The trial will achieve the following specific aims: Specific Aim 1: To compare the frequency of HDP (primary outcome), as well as other important secondary outcomes (gHTN, PE, preterm PE, PE-related adverse outcomes, aspirin-related safety outcomes, and patient-reported outcomes related to maternal health, pregnancy, and childbirth experiences) between the two aspirin treatment arms. Specific Aim 2: To compare the gestational age at birth and the frequency of adverse perinatal outcomes (preterm birth, perinatal death, small-for-gestational-age birth, neonatal intensive care unit admission, and complications of prematurity), as well as patient-reported outcomes related to maternal-infant bonding between the two aspirin treatment arms. Specific Aim 3: To use quantitative and qualitative analyses to elucidate facilitators and barriers associated with adherence to aspirin therapy in at-risk individuals during pregnancy in order to facilitate future implementation.