Low-Dose Aspirin During Pregnancy Benefits Some Women

Pregnant woman holding a pill bottle.

Key takeaways:

  • Low-dose aspirin may prevent or delay preeclampsia for certain women.
  • Though generally safe, aspirin during pregnancy isn’t for everyone.
  • Always get a health care professional’s approval before starting or stopping any medication, including aspirin.

Some women may need to take low-dose aspirin during pregnancy. Aspirin should only be used during pregnancy if a health care professional recommends it.

How aspirin helps

Aspirin is an over-the-counter drug that is used to relieve pain, reduce fever and lower inflammation. It also thins the blood, which helps prevent blood clots from forming. During pregnancy, a daily low dose of aspirin (usually 81 milligrams) might be recommended for some women.

Who needs aspirin during pregnancy?

Low-dose aspirin may be used to prevent or delay the onset of preeclampsia, which is severe high blood pressure that typically begins after 20 weeks of pregnancy. Preeclampsia occurs in up to 8% of pregnant women.

Most women deliver healthy babies and fully recover from preeclampsia. Yet in some cases, the condition can be life-threatening to the mother and unborn baby. It can cause liver or kidney damage and can more than double a woman’s chances for future heart disease and stroke.

The American Heart Association recommends women with chronic high blood pressure or a previous case of pregnancy-related high blood pressure take low-dose aspirin from 12 weeks until delivery. The Society for Maternal-Fetal Medicine, the American College of Obstetricians and Gynecologists and the U.S. Preventive Services Task Force also recommend low-dose aspirin after 12 weeks of pregnancy in women at high risk for preeclampsia, which usually means having one or more of the following:

  • History of preeclampsia, especially when accompanied by an adverse outcome
  • Pregnant with multiples
  • Chronic high blood pressure
  • Diabetes
  • Kidney disease
  • Autoimmune disease

Having more than one moderate risk factor for preeclampsia is also a sign that women may need low-dose aspirin during pregnancy. These risk factors include:

  • Obesity (body mass index over 30)
  • Family history of preeclampsia
  • First pregnancy
  • Being a Black woman (complications are associated with underlying societal and health inequities driven by structural racism)
  • Lower income
  • Age 35 or older
  • Personal health history, such as low birthweight or a previous pregnancy complication
  • In vitro fertilization

Is aspirin safe during pregnancy?

Low-dose aspirin therapy in pregnancy is generally considered safe for certain women and is associated with a low likelihood of serious maternal or fetal complications, according to guidelines. Women who are pregnant or plan to get pregnant should discuss the benefits and risks of taking low-dose aspirin with a health care professional. Some women, such as those with an aspirin allergy, should not take it. Research also does not support taking low-dose aspirin for the prevention of early pregnancy loss, fetal growth restriction, stillbirth or preterm birth.