Low Dose Aspirin for Preterm Preeclampsia Preventionmg/day Dose in High-risk Patients

This will be a randomized, open-label, controlled trial of patients at high risk of developing preeclampsia examining 81 mg/day vs 162mg/day daily ASA use. Currently, all patients that present to UVA Obstetric clinics are evaluated for development of preeclampsia per the current ACOG guidelines. If they screen positive per ACOG guidelines, then it is recommended they initiate 81mg/day ASA starting at 12 weeks of pregnancy and continuing until delivery. For this study, patients that present for early first trimester ultrasound (US) (for dating and/or genetic testing + ultrasound) will be offered enrollment in the study, and consenting patients will undergo double screening tests with ACOG and the FMF-based preeclampsia screen. This test will include first trimester uterine artery PI, assessment of maternal blood pressure, a maternal history and maternal serum markers including PAPP-A, PLGF, S-FLT, AFP. The first trimester preeclampsia screen will be performed between 10 weeks, 0 days and 13 weeks, 6 days of pregnancy. For the patients within the intervention group, repeat uterine artery PI measurements will be performed during the patient's 20-week anatomic survey ultrasound. Repeat maternal serum biomarkers will be collected with routine 28-week labs and at time of delivery (standard times for blood draws in pregnancy) for all enrolled patients. Patients will be followed longitudinally through their pregnancy and delivery and neonatal outcomes will be recorded. Delivery and timing of delivery will be based solely on obstetric indications regardless of status in the trial. All uterine artery Doppler measurements will be obtained by P.J. Kumar.