Is it safe to take aspirin during pregnancy?
Answer From Mary Marnach, M.D.
Aspirin usually is not recommended during pregnancy unless you have certain medical conditions.
Sometimes, health care providers advise pregnant people to take a low dose of aspirin if they have blood clotting disorders or a history of a condition called preeclampsia. Your health care provider also might suggest that you take low-dose aspirin if you've had several miscarriages or other pregnancy loss. A low dose of aspirin is about 60 to 100 milligrams (mg) a day. The typical low-dose aspirin you can buy without a prescription is 81 mg. Low-dose aspirin is safe to use throughout pregnancy.
Higher doses of aspirin typically are not recommended during pregnancy. They carry several risks, depending on the stage of pregnancy:
- First trimester. During the first trimester, higher doses of aspirin may raise the risk of pregnancy loss. Taking a high dose also could raise the risk of a baby having medical problems at birth, called congenital defects.
Second trimester. The U.S. Food and Drug Administration (FDA), advises pregnant people not to take medicines called nonsteroidal anti-inflammatory drugs (NSAIDs), after 19 weeks of pregnancy. Aspirin is a type of NSAID. Taking NSAIDs could cause rare but serious kidney problems in fetuses. That can lead to low levels of amniotic fluid. And that can cause more problems for the fetus.
If you need to take low-dose aspirin during pregnancy due to a medical condition, don't stop taking it at 19 weeks unless your health care provider tells you to do so. Ask your provider about the benefits and risks of aspirin in your situation.
- Third trimester. Along with the other risks, taking higher doses of aspirin during the third trimester of pregnancy raises the risk that a vessel in the fetus's heart will close too soon. If you have to take aspirin during the third trimester, you may need medical appointments often to check fetal health.
Use of high-dose aspirin for long periods of time during any part of pregnancy raises the risk of bleeding in the brain of premature infants.
If you need a pain reliever while you are pregnant, talk to your health care provider. Taking something other than aspirin, such as acetaminophen (Tylenol, others), may be a better choice.
Nov. 04, 2022
- AskMayoExpert. Analgesics in pregnancy. Mayo Clinic; 2021.
- Landon MB, et al., eds. Collagen vascular diseases in pregnancy. In: Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed Oct. 14, 2022.
- Naimi AI, et al. The effect of preconception-initiated low-dose aspirin on human chorionic gonadotropin-detected pregnancy, pregnancy loss, and live birth. Annals of Internal Medicine. 2021; doi:10.7326/M20-0469.
- Briggs GG, et al. Aspirin. In: Briggs Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. 12th ed. Wolters Kluwer Lippincott Williams & Wilkins; 2022. https://ovidsp.ovid.com. Accessed Oct. 14, 2022.
- FDA recommends avoiding use of NSAIDs in pregnancy at 20 weeks or later because they can result in low amniotic fluid. U.S. Food and Drug Administration. https://www.fda.gov/drugs/drug-safety-and-availability/fda-recommends-avoiding-use-nsaids-pregnancy-20-weeks-or-later-because-they-can-result-low-amniotic. Accessed Oct. 14, 2022.
- Marnach ML (expert opinion). Mayo Clinic. Oct. 18, 2022.