# EvidenceDigest: Aspirin Prophylaxis for Preeclampsia: Who Benefits
Clinical bottom line
Low-dose aspirin prophylaxis is recommended for pregnant women at high risk of preeclampsia, as it has been shown to reduce the incidence of this condition and associated complications. Identifying candidates for aspirin prophylaxis involves assessing risk factors such as a history of preeclampsia, chronic hypertension, and multiple gestations. Early initiation, ideally before 16 weeks of gestation, is crucial for optimal efficacy.
What the evidence shows
Recent studies and guidelines support the use of low-dose aspirin in preventing preeclampsia among high-risk populations. The ASPRE trial (2017) demonstrated that aspirin, initiated before 16 weeks of gestation, significantly reduced the incidence of preterm preeclampsia in women identified as high risk by first-trimester screening (PMID: 28657417). This trial highlighted the importance of early intervention in high-risk groups.
A meta-analysis by Roberge et al. (2017) confirmed the efficacy of aspirin in reducing the risk of preeclampsia, particularly when started before 16 weeks of gestation, with a notable reduction in the risk of severe outcomes such as preterm birth and fetal growth restriction (PMID: 28349659). This analysis supports the timing and population criteria for aspirin prophylaxis.
The U.S. Preventive Services Task Force (USPSTF) guidelines (2014, reaffirmed in 2021) recommend low-dose aspirin (81 mg daily) for women at high risk for preeclampsia, based on evidence of moderate benefit and low risk of harm (PMID: 25243785). These guidelines provide a framework for identifying candidates for aspirin prophylaxis based on individual risk factors.
Caveats and uncertainty
While aspirin prophylaxis is beneficial for high-risk women, its use in low-risk populations remains uncertain, with limited evidence supporting a significant benefit. The potential for side effects, such as gastrointestinal bleeding, although rare at low doses, should be considered. Furthermore, adherence to prophylaxis and the timing of initiation are critical factors influencing outcomes.
The identification of high-risk women relies on accurate risk assessment tools and clinical judgment, which may vary across different healthcare settings. Further research is needed to refine risk stratification methods and explore the potential benefits of aspirin in broader populations.
How this may change practice
The evidence supporting aspirin prophylaxis for preeclampsia may lead to its increased use in clinical practice, particularly for women with identifiable risk factors. As screening methods improve, more women may be identified as candidates for prophylaxis, potentially reducing the incidence of preeclampsia and its complications.
Clinicians should engage in shared decision-making with patients, discussing the potential benefits and risks of aspirin prophylaxis. Early initiation and adherence to therapy are crucial for maximizing benefits, and regular monitoring should be part of the care plan.