Study Shows Aspirin May Not Prevent Preeclampsia in All High-Risk Pregnancies: Biomarker Trends Reveal Clues
Hong Kong: A new study published in the American Journal of Obstetrics & Gynecology offers fresh insights into how key biomarkers behave during pregnancy in women at high risk for preterm preeclampsia, even when treated with preventive low-dose aspirin. Conducted by Dr. Long Nguyen-Hoang and colleagues from the Department of Obstetrics and Gynaecology at The Chinese University of Hong Kong, the research highlights patterns that may help refine risk prediction and management strategies.
The prospective longitudinal study involved 2,007 women with singleton pregnancies who were screened in their first trimester at the Prince of Wales Hospital, Hong Kong, between January 2020 and May 2023. Participants were classified into high- and low-risk categories based on the Fetal Medicine Foundation's first-trimester algorithm, which incorporates maternal history, mean arterial pressure, uterine artery pulsatility index (UtA-PI), and placental growth factor (PlGF).
Women identified as high-risk (with a predicted risk ≥1:100 for preterm preeclampsia) were prescribed low-dose aspirin—either 100 mg or 160 mg daily, depending on body weight—starting before 16 weeks of gestation. These women continued the regimen until 36 weeks, delivery, or until the onset of preeclampsia. Low-risk participants who did not receive aspirin were matched by age, weight, and scan date to serve as a control group.
Biomarkers were assessed at three gestational windows: 12–15+6 weeks, 20–24+6 weeks, and 30–37+6 weeks. The team measured levels of mean arterial pressure, UtA-PI, PlGF, and soluble fms-like tyrosine kinase-1 (sFlt-1), with data analyzed using log-transformed multiples of the median to allow for standard comparisons.
The study included 403 low-risk women without preeclampsia, 1,471 high-risk women who did not develop the condition, and 133 high-risk women who did.
The study revealed the following findings:
- The low-risk group consistently demonstrated lower mean arterial pressure, UtA-PI, and sFlt-1 levels, along with higher PlGF levels across all stages of pregnancy compared to high-risk groups.
- Among high-risk women who developed preeclampsia, mean arterial pressure was significantly higher starting from the first trimester.
- These women also showed increased UtA-PI and decreased PlGF levels beginning in the second trimester.
- In the third trimester, sFlt-1 levels were notably higher in the preeclampsia group.
- These biomarker patterns persisted despite the use of low-dose aspirin, indicating a possible underlying disease progression that aspirin may not effectively modify.
"The findings indicate that despite aspirin prophylaxis, certain biomarker profiles may predict the onset of preeclampsia in high-risk pregnancies. The study emphasizes the potential of using these biomarker trends—particularly mean arterial pressure, UtA-PI, PlGF, and sFlt-1—for enhanced monitoring and individualized risk assessment in clinical practice," the authors concluded.
Reference:
Nguyen-Hoang L, Sahota DS, Tai AST, Chen Y, Feng Q, Wang X, Moungmaithong S, Leung MBW, Tse AW, Wong NKL, Kwan AH, Lau SL, Lee NMW, Chong MKC, Poon LC. Effect of aspirin on biomarker profile in women at high risk for preeclampsia. Am J Obstet Gynecol. 2025 Jun;232(6):561.e1-561.e20. doi: 10.1016/j.ajog.2024.11.007. Epub 2024 Nov 14. PMID: 39547345.
