Answering the Question on Aspirin Dosage

Since 2014, US professional societies emphasized low-dose aspirin in their preeclampsia prevention guidelines. All prenatal patients should be screened, and those with certain risk factors should be placed on aspirin.

Aspirin typically comes in 81-mg tablets in the US, but data from Europe suggests that higher doses may provide more protection. So, could 162-mg of aspirin be more effective at preventing preeclampsia than 81-mg for Americans?

A new five-year randomized control trial(1) launched in late 2024 to fully answer that question. The study will also look at outcomes for the mother and baby. Results from the study can guide providers on how much aspirin to prescribe to prevent preeclampsia.

Hypertensive disorders of pregnancy (HDP), which include conditions like preeclampsia, eclampsia, HELLP syndrome and gestational hypertension, affect 5-8% of all pregnancies in the US. More alarmingly, HDPs are on the rise: recent numbers from the National Center for Health Statistics found a 74% increase in the prevalence of HDPs from 2015 to 2022.

What is a randomized controlled trial?

A randomized controlled trial (RCT) is a clinical study that places participants in different groups. One group may receive the treatment. The other group does not. While some studies control outside variables, this study will test aspirin usage in real-world settings. This is called a pragmatic comparative effectiveness study. The goal is to give key decision makers a clear idea of benefits and risks of a health intervention.

In this study, each patient is taking two pills each day. Patients assigned to the 162-mg dose take two 81-mg aspirin pills. Patients assigned to the 81-mg dose take one 81-mg aspirin and one placebo. A placebo is a pill with no active ingredients. Researchers will meet with study participants during their pregnancies to also study any side effects. The benefits of this study is that it will include lots of patients from all across the US. They will be made up of pregnant patients of all demographics. And the study design will be replicated in multiple test sites for consistent results.

What will this aspirin study do?

The study will include over 10,000 prenatal patients at eleven different research sites across the United States, led by The Ohio State University Wexner Medical Center (OSUWMC) and Northwestern University Feinberg School of Medicine.

The study is funded by the Patient-Centered Outcomes Research Institute (PCORI), which emphasizes including patient voices in all parts of the research process. This trial will include patients through:

• Preeclampsia Foundation representation on the study's steering committee
• Reviewing materials with patient advisory boards and councils
• Hosting community advisory boards at each research site
• Conducting post-study interviews with participants
• Reviewing study results and next steps alongside patient representatives

The goal of this study is to provide a definitive recommendation on how much aspirin may help patients at risk for HDPs.

Why are patient perspectives important in research?

Understanding patient perspectives is really important inresearch. They help make sure that the questions we ask, the way we design studies, and the outcomes we look for are all relevant to what patients actually need and experience. By focusing on patient voices, we can get results that matter and can be easily used in real-life medical practice. This ultimately leads to better patient care because we’re tackling the issues that truly concern them. Plus, it allows us to target the most important areas for research and create treatments that resonate with what patients go through in everyday life.

The patient voice and experience are integral to the mission of the Preeclampsia Foundation so we take every opportunity to include the patient perspective in our work.

More about the study:

The clinical coordinating center team at OSUWMC includes Principal Investigator Maged Constantine, MD, MBA, Investigators Kara Rood, MD, and Bill Grobman, MD, MBA, Project Manager Taryn Summerfield, MS, Senior Study Coordinator, Melanie Paglione, RN, BSN, Engagement Project Manager, Anne Trinh, BS, MPH, Regulatory Compliance Officer, Huban Kutay, PhD, Qualitative Researcher Ann McLearney, ScD, MS, and Social Epidemiologist, Kiarri Kershaw, PhD.

The study is conducted by the ASPIRIN Study Consortium consisting of eleven clinical centers: The Ohio State University, Northwestern University, Columbia University, Eastern Virginia Medical School, University of California San Francisco, Cedars Sinai Medical Center, University of New Mexico, University of North Carolina, University of Pittsburgh, University of Texas Health Science Center, and University of Mississippi.

Information will be entered into a central database maintained at Northwestern University Feinberg School of Medicine, Northwestern University Data Analysis and Coordinating Center (NUDACC) in Chicago, IL. The research team at Northwestern University will analyze all information from this trial and will not have access to any direct identifiable information. The data coordinating center team includes Principal Investigator Denise Scholtens, PhD, and researchers Abigail Smith, PhD and Nathan Pruneau Gill, PhD.