Preeclampsia is a serious condition that can develop during pregnancy, typically after 20 weeks of gestation. It is characterized by high blood pressure, often accompanied by signs of damage to other organ systems, such as the kidneys or liver. While symptoms may not always be obvious, routine prenatal check-ups help identify its early signs, including elevated blood pressure and protein in the urine. For certain pregnancies, healthcare providers frequently recommend low-dose aspirin as a preventive measure against this potentially severe complication.
The Preventive Role of Aspirin
Preeclampsia often stems from issues with placental blood vessels, leading to reduced blood flow. Low-dose aspirin counteracts this by inhibiting enzymes involved in producing prostaglandins that narrow blood vessels.
Aspirin’s anti-platelet properties reduce platelet stickiness, improving blood flow. It preferentially reduces thromboxane, which promotes clotting and vessel constriction, while having less effect on prostacyclin, which widens vessels. This rebalancing supports healthier placental blood flow, preventing the vascular dysfunction linked to preeclampsia.
Identifying High-Risk Pregnancies
Healthcare providers assess specific risk factors to identify individuals who would benefit from aspirin prophylaxis. Guidelines from medical bodies like the American College of Obstetricians and Gynecologists (ACOG) and the U.S. Preventive Services Task Force (USPSTF) inform these recommendations.
High-risk factors often prompting a recommendation for low-dose aspirin include:
- A history of preeclampsia in a previous pregnancy
- Carrying multiple fetuses
- Chronic high blood pressure
- Type 1 or type 2 diabetes
- Kidney disease
- Autoimmune conditions like systemic lupus erythematosus or antiphospholipid syndrome
Aspirin may also be considered if an individual has several moderate-risk factors, such as:
- Being pregnant for the first time
- Being 40 years of age or older
- Obesity with a body mass index (BMI) over 35
- A family history of preeclampsia
Recommended Dosage and Timing
The standard recommendation for preeclampsia prevention in the United States is low-dose aspirin, typically an 81-milligram tablet. This dosage differs from regular-strength aspirin. While some evidence suggests 150 mg might be more effective, 81 mg remains a common and reasonable dosage for high-risk individuals.
Initiating this regimen early is important for effectiveness. Healthcare providers generally advise starting low-dose aspirin daily between 12 and 16 weeks of gestation, ideally around 12 weeks. Continuing daily until delivery, or as advised by a doctor, ensures consistent protective effects. A healthcare professional determines the specific timing and dosage, tailoring it to individual circumstances.
Safety Considerations
Studies affirm the safety of low-dose aspirin for preeclampsia prevention in high-risk populations. Its safety profile differs from higher-dose aspirin, which is typically avoided during pregnancy. The benefits of preventing preeclampsia for both the pregnant individual and the baby generally outweigh potential side effects.
While safe for this purpose, low-dose aspirin can cause minor side effects. These may include a slightly increased risk of minor bleeding, like nosebleeds or easy bruising, and occasional stomach irritation. For individuals at increased risk of preeclampsia, the protective advantages significantly outweigh these minimal concerns. Low-dose aspirin should only be taken during pregnancy under a healthcare provider’s direct guidance.