Low-dose aspirin prophylaxis is recommended in women at high risk of preeclampsia, according to new recommendations from the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM). The ACOG and SMFM support the US Preventive Services Task Force (USPSTF) guideline criteria for prevention of preeclampsia. The ACOG/SMFM recommendations include:

• Low-dose aspirin (81 mg/day) prophylaxis is recommended in women at high risk of preeclampsia and should be initiated between 12 weeks and 28 weeks of gestation (optimally before 16 weeks) and continued daily until delivery.
• Low-dose aspirin prophylaxis should be considered for women with >1 of several moderate risk factors for preeclampsia.
• Low-dose aspirin prophylaxis is not recommended solely for the indication of prior unexplained stillbirth, in the absence of risk factors for preeclampsia.
• Low-dose aspirin prophylaxis is not recommended for prevention of fetal growth restriction, in the absence of risk factors for preeclampsia.
• Low-dose aspirin prophylaxis is not recommended for the prevention of spontaneous preterm birth, in the absence of risk factors for preeclampsia.
• Low-dose aspirin prophylaxis is not recommended for the prevention of early pregnancy loss.