Low-dose aspirin (81 mg/day), initiated at 12 weeks (or between 12 and 28 weeks).
Both ACOG and the USPSTF recommend this in high-risk women.
In 2013, ACOG defined high-risk women as women with a history of early-onset preeclampsia and preterm delivery at less than 34 0/7 weeks of gestation, OR women with more than one (i.e. ≥ 2) prior pregnancy complicated by preeclampsia.
In 2014, the USPSTF made a similar recommendation defining high-risk women as:
Clinical Risk Assessment for Preeclampsia*
| Risk Level | Risk Factors | Recommendation |
|---|---|---|
| High† | History of preeclampsia, especially when accompanied by an adverse outcome Multifetal gestation Chronic hypertension Type 1 or 2 diabetes Renal disease Autoimmune disease (systemic lupus erythematosus, antiphospholipid syndrome) |
Recommend low-dose aspirin if the patient has ≥1 of these high-risk factors |
| Moderate‡ | Nulliparity Obesity (body mass index >30 kg/m2) Family history of preeclampsia (mother or sister) Sociodemographic characteristics (African American race, low socioeconomic status) Age ≥35 years Personal history factors (e.g., low birthweight or small for gestational age, previous adverse pregnancy outcome, >10-year pregnancy interval) |
Consider low-dose aspirin if the patient has several of these moderate-risk factors§ |
| Low | Previous uncomplicated full-term delivery | Do not recommend low-dose aspirin |
* Includes only risk factors that can be obtained from the patient medical history. Clinical measures, such as uterine artery Doppler ultrasonography, are not included.
† Single risk factors that are consistently associated with the greatest risk for preeclampsia. The preeclampsia incidence rate would be approximately ≥8% in a pregnant woman with ≥1 of these risk factors.
‡ A combination of multiple moderate-risk factors may be used by clinicians to identify women at high risk for preeclampsia. These risk factors are independently associated with moderate risk for preeclampsia, some more consistently than others.
§ Moderate-risk factors vary in their association with increased risk for preeclampsia.
References/ Further Reading
https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/low-dose-aspirin-use-for-the-prevention-of-morbidity-and-mortality-from-preeclampsia-preventive-medication
https://www.acog.org/Clinical-Guidance-and-Publications/Practice-Advisories/Practice-Advisory-Low-Dose-Aspirin-and-Prevention-of-Preeclampsia-Updated-Recommendations