There are some complications during pregnancy, such as preeclampsia and gestational hypertension, that increase the risk of developing dangerously high blood pressure and injury of the brain, lungs, kidneys and liver. These blood pressure complications impact nearly one in seven pregnant individuals, are increasing by about 10 percent every year, and disproportionately affect minoritized communities and other groups with historical disadvantage. Currently, the only treatment for these conditions is delivery, which often leads to babies being born too early and having increased risks for complications such as bleeding in the brain and infections.
Given the high frequency, related complications and inequities, it is important to improve treatment methods. Many professional societies, such as the Society for Maternal-Fetal Medicine, say that pregnant people should take aspirin every day to prevent these blood pressure complications. While 81 mg of aspirin is often used, because it is the dose available in the United States, a higher dose may work better for patients, but this is uncertain. It is also important to show that aspirin will work well in all people and to understand what factors make it difficult or easier for people to take aspirin after it has been recommended.
In the United States no clinical trials have compared how well different doses of aspirin work to prevent blood pressure complications in pregnant people. The overall goals of this large study are to determine whether:
- A higher dose of aspirin leads to better outcomes for the mother and child
- Aspirin can lessen health disparities (such as in the frequency of blood pressure problems in pregnancy)
- Strategies can be identified to help pregnant people use aspirin as it has been prescribed
This study will randomize 10,742 pregnant people at higher risk for blood pressure problems in pregnancy and who are represent diversity in multiple ways (such as their race, pregnancy risk factors and geography) to receive one of two available doses of aspirin: 81 mg or 162 mg per day. People will then be followed from when they start the study until six weeks after delivery in order to compare those on the two different doses according to:
- Their blood pressure complications, overall health and birth experience
- Whether they have a baby that is too small, born too early, receives special care after delivery, has issues with bonding or does not survive
- Factors that make it easier or harder for patients to take aspirin daily
This study will help answer an important question that will improve the health of all pregnant people and their babies and may also lessen health disparities. When completed, this will be the largest and most up-to-date study focused on the ideal dose of aspirin to prevent blood pressure problems in pregnancy. Given that aspirin is widely used, cheap, accessible and safe in pregnancy, the researchers believe that findings from this study will quickly be utilized to guide care for people at increased risk for blood pressure problems in pregnancy. The study team has built a diverse research team that is supported by key stakeholders—including people who pay for, advocate for and receive health care—to develop a plan to make sure the study findings are shared broadly and can be used to help protect the populations most at risk for blood pressure problems in pregnancy.
*All proposed projects, including requested budgets and project periods, are approved subject to a programmatic and budget review by PCORI staff and the negotiation of a formal award contract.