(746) Optimal Aspirin Dose in Preeclampsia Prevention: A Retrospective Comparison of 81 mg and 162 mg

Friday, January 31, 2025

10:30 AM – 12:30 PM

Submitting Author and Presenting Author(s)

Ellen M. Murrin, DO (she/her/hers)

Maternal Fetal Medicine Fellow
Inova Fairfax Medical Campus
Falls Church, VA, United States

Coauthor(s)

SS

Scott Sullivan, MD, MSCR

Director of Maternal Fetal Medicine
Inova Fairfax Medical Campus
Fairfax, Virginia, United States
GS

Garima Sharma, MD

Director of Cardio-Obstetrics and Women's Cardiovascular Health
Inova Heatlh
Norfolk, Virginia, United States
OA

Olayinka Agboola, MD, MPH

Inova Fairfax Medical Campus
Fairfax, Virginia, United States
GM

G. Larry Maxwell, MD

President of Inova Women's Service Line
Inova Fairfax Medical Campus
Fairfax, Virginia, United States
George R. Saade, MD (he/him/his)

Professor and Chair, Associate Dean for Women's Health Obstetrics and Gynecology
Macon & Joan Brock Virginia Health Sciences Eastern Virginia Medical School at Old Dominion University
Norfolk, Virginia, United States
Antonio F. Saad, MBA, MD (he/him/his)

Director of Perinatal Research Unit, MFM Fellowship Program Director
Inova Health
Falls Church, Virginia, United States

Objective: There is a lack of consensus regarding the optimal dosing for aspirin (ASA) in preeclampsia prevention, with recommendations ranging from 75 to 162 mg daily. This practice reflects evidence suggesting that dosages above 100 mg are most effective at reducing preeclampsia risk. Our objective was to compare the incidence of preeclampsia in patients taking 81 mg versus 162 mg ASA daily using national data.

Study Design: A retrospective cohort study was conducted using the Cosmos Epic database. Data from pregnancies between June 2021 and July 2024 in which ASA was prescribed were pooled based on ICD-10 codes. Baseline clinical characteristics and risk factors were compared between groups. Two-sided chi-square tests and odds ratios were used for statistical analysis.

Results: A total of 328,310 pregnant patients taking ASA were identified—81.2% in the 81 mg group and 18.8% in the 162 mg group. The 162 mg ASA group had significantly higher rates of BMI ≥30, multiple gestation, pre-gestational diabetes, antiphospholipid syndrome, chronic kidney disease, and chronic hypertension (Table 1). Obstetric outcomes were poorer in this group, with increased rates of cesarean delivery and birth weight < 2500 g. More patients in the 162 mg group developed preeclampsia compared with the 81 mg group (OR 1.31, 95% CI 1.29-1.35). This difference remained significant despite accounting for the above-mentioned confounding variables (aOR 1.11, 95% CI 1.11-1.13; Table 2).

Conclusion: In this national dataset, a higher daily dose of aspirin (162 mg) was not more effective than a lower dose (81 mg) in reducing the risk of preeclampsia, despite correcting for differences in risk factors that may have prompted clinicians to use a higher dose. More research is needed to confirm these findings and optimize aspirin dosing guidelines for preeclampsia prevention.