Preeclampsia is a serious hypertensive disorder of pregnancy that can put both mothers and babies at risk. Low-dose aspirin can help prevent it in some high-risk pregnancies, but identifying who should receive it can be challenging.

Current guidelines recommend that women with one or more high-risk factors take low-dose aspirin, and women with several moderate-risk factors may also benefit from low-dose aspirin to prevent or delay the onset of preeclampsia. Low-dose aspirin ranges from 60-150 mg daily, but in the United States, the usual dose is an 81 mg tablet. Research studies are examining whether 81- or 162-mg doses are more effective.

This observational cohort study looked at what happened when Parkland Health, a high-volume community health system with obstetric services, began offering 162 mg of aspirin daily to all pregnant patients who started prenatal care by 16 weeks. They directly dispensed the medication during prenatal visits.

The results were encouraging. Severe preeclampsia decreased from 6.9% to 5.1% after universal aspirin prophylaxis was introduced. This benefit was seen in patients with and without chronic high blood pressure. There was also no increase in placental abruption (when the placenta separates too early) or heavy bleeding after birth.

“Universal dispensation of 162 mg aspirin daily at the first prenatal visit in a population with a high rate of hypertensive disorders was associated with a population-level reduction in the development of preeclampsia with severe features in patients with and without chronic hypertension, without an increase in abruption or postpartum hemorrhage. This study demonstrates the possible benefit of a universal approach to aspirin prescribing in high-risk populations, especially if direct dispensation is performed.”

Take-Home Message: The study supports that 162 mg aspirin daily started before 16 weeks reduces preeclampsia. Making low-dose aspirin easy to access for all patients in a high-risk population may help prevent severe preeclampsia without increasing certain pregnancy and birth complications. Further research is needed to continue exploring if 81- or 162-mg doses are more effective and how direct dispensation improves outcomes.

To learn more about preeclampsia risk factors and aspirin use, visit our webpage: Ask About Aspirin.

Citation:

Elaine Duryea, Anne Ambia, Jessica Pruszynski, Joyce Miller, Sharon Hubbard, Carrie Berge, David Nelson, Catherine Spong,

Universal aspirin dispensation for prevention of preeclampsia in a high-risk population, American Journal of Obstetrics and Gynecology, 2026,ISSN 0002-9378, https://doi.org/10.1016/j.ajog.2026.08.036. (https://www.sciencedirect.com/science/article/pii/S0002937826004618).