Introduction
Pre-eclampsia (PEC) is a morbid and potentially lethal complication of pregnancy and is more common in women with risk factors such as hypertension, diabetes, autoimmune disease, kidney disease or multifetal pregnancies. Low dose aspirin (ASA) is currently the only prophylactic therapy known to decrease PEC in this patient population. However, currently, there is no prospective literature comparing various low-dose ASA formulations in the risk reduction of PEC. In the USA, the currently available low-dose ASA is over-the-counter and found in 81 mg tablets. Therefore, when clinicians initiate low-dose ASA therapy, they may prescribe one or two tablets of 81 mg per day without comparative evidence to guide their decision. Our objective is to prospectively compare pregnant patients on 81 mg vs 162 mg of ASA and determine a possible dose response in the prevention of PEC.
Methods and analysis
We designed a pragmatic phase 3 prospective randomised open label blinded-end point clinical trial with parallel assignment between two groups of pregnant people at high risk for PEC, as defined by the US Preventive Services Task Force and American College of Obstetricians and Gynecologists (ACOG). The primary outcome is the incidence of preterm (