Low-dose aspirin clearly is effective for reducing the risk of preeclampsia
American College of Obstetricians and Gynecologists. Hypertension in pregnancy. Report of the American College of Obstetricians and Gynecologists' Task Force on Hypertension in Pregnancy. Obstet Gynecol. 2013;122(5):1122-1131.
Henderson JT, Whitlock EP, O'Connor E, Senger CA, Thompson JH, Rowland MG. Low-dose aspirin for prevention of morbidity and mortality from preeclampsia: a systematic evidence review for the US Preventive Services Task Force. Ann Intern Med. 2014;160(10):695-703.
LeFevre ML; US Preventive Services Task Force. Low-dose aspirin use for the prevention of morbidity and mortality from preeclampsia: US Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;161(11):819-826.
American College of Obstetricians and Gynecologists. Practice advisory on low-dose aspirin and prevention of preeclampsia: updated recommendations. http://www.acog.org/About-ACOG/News-Room/Practice-Advisories/Practice-Advisory-Low-Dose-Aspirin-and-Prevention-of-Preeclampsia-Updated-Recommendations. Published July 11, 2016. Accessed December 6, 2016.
In the 2013 ACOG Task Force on Hypertension in Pregnancy report, low-dose aspirin (60-80 mg) was recommended to be initiated in the late first trimester to reduce preeclampsia risk for women with:
- prior early onset preeclampsia with preterm delivery at <34 weeks' gestation, or
- preeclampsia in more than one prior pregnancy.
This recommendation was based on several meta-analyses that demonstrated a 10% to 17% reduction in risk with no increase in bleeding, placental abruption, or other adverse events.
In 2014, the US Preventive Services Task Force (USPSTF) conducted a systematic evidence review of low-dose aspirin use for prevention of morbidity and mortality from preeclampsia. That report revealed a 24% risk reduction of preeclampsia in high-risk women treated with low-dose aspirin, as well as a 14% reduction in preterm birth and a 20% reduction in fetal growth restriction. A final statement from the USPSTF in 2014 recommended low-dose aspirin (60-150 mg) starting between 12 and 28 weeks' gestation for women at "high" risk who have:
- a history of preeclampsia, especially if accompanied by an adverse outcome
- multifetal gestation
- chronic hypertension
- diabetes (type 1 or type 2)
- renal disease
- autoimmune disease (such as systematic lupus erythematosus, antiphospholipid syndrome).
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Start offering aspirin to pregnant women at high risk for preeclampsia
As of July 11, 2016, ACOG supports this expanded list of high-risk conditions. Additionally, the USPSTF identified a "moderate" risk group in which low-dose aspirin may be considered if a patient has several risk factors, such as obesity, nulliparity, family history of preeclampsia, age 35 years or older, or another poor pregnancy outcome. ACOG notes, however, that the evidence supporting this practice is uncertain and does not make a recommendation regarding aspirin use in this population. Further study should be conducted to determine the benefit of low-dose aspirin in these patients as well as the long-term effects of treatment on maternal and child outcomes.