Practice Advisory on Low-Dose Aspirin and Prevention of Preeclampsia: Updated Recommendations

The American College of Ob/Gyn 

July 11, 2016

Current ACOG recommendations regarding the use of low-dose aspirin for the prevention of preeclampsia are based on the cumulative efforts of the Task Force on Hypertension in Pregnancy; the Task Force report was issued by ACOG in November 2013 (1). That report was based on an extensive review of the available evidence at that time. In that report, the use of low-dose aspirin, beginning in the late first trimester, was suggested for women with a history of early-onset preeclampsia and preterm delivery at less than 34 0/7 weeks of gestation, or in women with more than one prior pregnancy complicated by preeclampsia.

A systematic evidence review was conducted by the U.S. Preventive Services Task Force (USPSTF) and published as a clinical guideline in September 2014 (2,3). In this guideline, the USPSTF recommended the use of low-dose aspirin after 12 weeks of gestation in women at high-risk of preeclampsia. Although the ACOG recommendations also address women at high-risk (criteria listed above), the criteria for determining high-risk in the USPSTF recommendations are more expansive. In the USPSTF recommendations, women are considered to be at high-risk for preeclampsia if one or more of the following risk factors are present:

  • 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)

The USPSTF review also identified “moderate” risk factors, for which low-dose aspirin might be considered if several moderate risk factors are present, although the evidence to support low-dose aspirin in the setting of moderate risk factors is uncertain (3). It is important to recognize that other organizations recommend consideration of low-dose aspirin in women at risk for preeclampsia, although the risk-factor criteria may vary somewhat (4,5).

Based on evidence supporting a broader list of risk factors of preeclampsia for which low-dose aspirin may provide benefit and based on more recent, evolving expert consensus, ACOG supports the recommendation to consider the use of low-dose aspirin (81 mg/day), initiated between 12 and 28 weeks of gestation, for the prevention of preeclampsia, and recommends using the high-risk factors as recommended by the USPSTF and listed above.


(1) American College of Obstetricians and Gynecologists. Hypertension in pregnancy. Washington, DC: American College of Obstetricians and Gynecologists; 2013. Available at: Retrieved July 7, 2016.

(2) 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 U.S. Preventive Services Task Force. Ann Intern Med 2014;160:695-703.

(3) LeFevre ML. Low-dose aspirin use for the prevention of morbidity and mortality from preeclampsia: U.S. Preventive Services Task Force recommendation statement. U.S. Preventive Services Task Force. Ann Intern Med 2014;161:819-26.

(4) World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. Geneva: WHO; 2011. Available at: Retrieved July 7,2016.

(5) National Institute for Health and Care Excellence. Quality statement 2: Antenatal assessment of pre-eclampsia risk. In: Hypertension in pregnancy. Manchester: NICE; 2013. p. 16-9. Available at: Retrieved July 7, 2016.

This Practice Advisory was developed by the American College of Obstetricians and Gynecologists in collaboration with Christopher M. Zahn, MD; Joseph R. Wax, MD; and T. Flint Porter, MD.

A Practice Advisory is issued when information on an emergent clinical issue (e.g. clinical study, scientific report, draft regulation) is released that requires an immediate or rapid response, particularly if it is anticipated that it will generate a multitude of inquiries. A Practice Advisory is a brief, focused statement issued within 24-48 hours of the release of this evolving information and constitutes ACOG clinical guidance. A Practice Advisory is issued only online for Fellows but may also be used by patients and the media. Practice Advisories are reviewed periodically for reaffirmation, revision, withdrawal or incorporation into other ACOG guidelines.

This document reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed.

The American College of Obstetricians and Gynecologists (The College), a 501(c)(3) organization, is the nation’s leading group of physicians providing health care for women. As a private, voluntary, nonprofit membership organization of  more than 57,000 members, The College strongly advocates for quality health care for women, maintains the highest standards of clinical practice and continuing education of its members, promotes patient education, and increases awareness among its members and the public of the changing issues facing women’s health care. The American Congress of Obstetricians and Gynecologists (ACOG), a 501(c)(6) organization, is its companion organization.

American Congress of Obstetricians and Gynecologists
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