Aspirin for the Prevention of Preeclampsia in Women With Stage 1 Hypertension

In 2017, the American College of Cardiology and the American Heart Association changed the diagnostic criteria for hypertension in non-pregnant adults. The parameters for the diagnosis of stage 1 hypertension were revised from a systolic blood pressure (BP) of 140 to 130 mm Hg and a diastolic BP of 90 to 80 mm Hg. Based on new criteria, stage 1 hypertension is associated with a 2-3 fold increased risk of preeclampsia. There are no data regarding prevention of preeclampsia in women with stage 1 hypertension. Low-dose aspirin has been used during pregnancy to prevent preeclampsia for women at high-risk for preeclampsia. Although the precise mechanism remains uncertain, it is possible that low-dose aspirin improves placental perfusion, which results in a decreased rate of preeclampsia. A study that examines the effect of low-dose aspirin on placenta vasculature and tissue elastography by using novel ultrasound tools would be useful. The 2017 Aspirin for Evidence-Based Preeclampsia Prevention trial compared 150 mg aspirin with placebo in women at high-risk of preeclampsia based on a first-trimester screening. They found a significant decrease in the rate of preterm preeclampsia (4.3% vs. 1.6%; P \<0.01). Since this study used the screening algorithm including first-trimester serum markers and uterine artery Doppler, the generalizability in the U.S. women with stage 1 hypertension is limited. Our pilot study will examine 1) the effect of low-dose aspirin 81 mg in women with stage 1 hypertension on placental vasculature and shear-wave elastography; 2) the rate of preterm preeclampsia in women with stage 1 hypertension in a control group and in pregnancies treated with low-dose aspirin 81 mg; 3) feasibility of conducting a larger multicenter randomized controlled trial on this subject.