Daily aspirin in pregnancy reduces risk of preeclampsia

Researchers report that prescribing daily aspirin to all pregnant patients at their first prenatal clinical visit is associated with an overall reduction in the onset of severe preeclampsia

The new findings were presented on Feb. 11, 2026 at the Society for Maternal-Fetal Medicine (SMFM)2026 Pregnancy Meeting.

“Implementation of universal aspirin dispensation at the first prenatal visit was associated with a population-level reduction in the development of SPE [severe preeclampsia ] in patients with and without chronic hypertension, without an increase in hemorrhage or abruption,” the authors said.

As background, they noted that preeclampsia is a potentially life-threatening complication of pregnancy which can cause dangerously high blood pressure and damage to liver, kidneys, or brain.

The data for the study includes all deliveries at a public hospital in Dallas Texas between April 2020 to July 2025.  On August 3, 2022 the researchers began direct dispensation of aspirin 162mg daily to all subjects presenting for prenatal care ≤ 16 weeks gestation.

The researchers compared data on two cohorts of 18,457 subjects each, enrolled before and after aspirin implementation.

They found that subjects in the aspirin group achieved a significant 29% lower rate of severe preeclampsia compared to the non-aspirin group (7.12% vs. 5.19%, p< 0.001).

They also reported that time to a severe preeclampsia diagnosis was significantly longer in the aspirin group (p< 0.001).

Subjects diagnosed with preexisting chronic hypertension who were given aspirin were also less likely to develop severe preeclampsia. The investigators reported no increased risk of maternal hemorrhage or placental abruption with aspirin therapy.

“Implementation of directly-dispensed aspirin in this high-risk pregnant population appeared to delay the onset, and for some patients completely prevent the development of preeclampsia with severe features,” said lead researcher Elaine L. Duryea, MD, Associate Professor in the Department of Obstetrics and Gynecology at the University of Texas Southwestern Medical Center in Dallas, and Chief of Obstetrics at Parkland Health. “While we cannot be sure that similar effects will be observed in other patient populations, there was no evidence of harm caused by aspirin administration.”