From the Guidelines
Aspirin is crucial in preventing preeclampsia as it significantly reduces the risk of morbidity and mortality from this condition in high-risk women, and its use is recommended by the USPSTF as a preventive medication after 12 weeks of gestation 1. The importance of aspirin in preventing preeclampsia cannot be overstated, given that preeclampsia is a serious health problem affecting pregnant women, contributing to both maternal and infant morbidity and mortality 1.
Key Points to Consider
- The USPSTF recommends the use of low-dose aspirin (81 mg/d) as preventive medication after 12 weeks of gestation in women who are at high risk for preeclampsia 1.
- Women who benefit most from aspirin therapy include those with previous preeclampsia, chronic hypertension, diabetes, kidney disease, autoimmune disorders, or multiple risk factors such as first pregnancy, age over 35, obesity, or family history of preeclampsia.
- Aspirin works by inhibiting thromboxane production while preserving prostacyclin, which improves the balance between these compounds and promotes better placental development and blood flow, thus preventing the abnormal placentation that leads to preeclampsia.
- The medication is generally safe during pregnancy at low doses, with minimal side effects like mild stomach upset, and should be taken at bedtime for maximum effectiveness.
Clinical Considerations
- Women should consult their healthcare provider before starting this preventive therapy to assess their risk factors and determine the appropriate timing and dosage of aspirin.
- The USPSTF classification of levels of certainty about net benefit and grades for recommendations should be considered when making clinical decisions 1.
From the Research
Importance of Aspirin in Preventing Preeclampsia
- Aspirin has been shown to be effective in reducing the incidence of preeclampsia in high-risk pregnant women 2, 3, 4, 5, 6.
- The optimal dosage of aspirin for preventing preeclampsia is still a topic of debate, with studies suggesting that doses of 80-100 mg/day 3 or 150 mg/day 2, 4 may be more effective than lower doses.
- Aspirin has been shown to reduce the risk of preeclampsia in twin pregnancies, particularly when started before 16 weeks of gestation and at a dose of >100 mg/day 6.
Mechanism of Action
- Aspirin works by inhibiting the production of thromboxane A2, a potent vasoconstrictor that can contribute to the development of preeclampsia 2.
- Aspirin also has anti-inflammatory properties, which may help to reduce the risk of preeclampsia by decreasing inflammation in the placenta 3.
Clinical Recommendations
- The American College of Obstetricians and Gynecologists recommends initiation of 81 mg of aspirin daily for women at risk of preeclampsia between 12 and 28 weeks' gestation 4.
- The Royal College of Obstetricians and Gynaecologists recommends 150 mg of aspirin daily for women at high risk of preeclampsia 4.
- The optimal timing and dosage of aspirin for preventing preeclampsia may vary depending on individual circumstances, and further research is needed to determine the most effective regimen 5.