You might have heard that aspirin is considered unsafe to take during pregnancy, and in one regard that’s true: full-strength aspirin (325 mg or higher) does increase the risk for certain issues with fetal development. However, more and more data suggest that low-dose aspirin (81 mg) is not only safe to take during pregnancy, but can even reduce a pregnant mother’s chances of developing preeclampsia if she is at risk for it.
What is preeclampsia?
Preeclampsia is a pregnancy complication that, according to the March of Dimes, affects 2 to 8 percent of all pregnancies. Preeclampsia involves high blood pressure and signs that organs aren’t working as well as they should be (such as protein in urine). Preeclampsia is usually diagnosed in the third trimester, and if it is, most healthcare providers recommend close observation until delivery. This may mean frequent monitoring in an outpatient setting, or, depending on the severity and the healthcare provider, may mean staying in the hospital until delivery. Preeclampsia’s symptoms usually go away in the days and weeks after giving birth.
Is there any way to prevent preeclampsia?
Because researchers still don’t understand exactly why some women develop preeclampsia, there’s no great one-size-fits-all method of preventing it. However, recent studies suggest that low-dose aspirin therapy can help prevent preeclampsia in women with certain risk factors that make preeclampsia more likely to develop. Women with these risk factors who begin low-dose aspirin therapy around 12 weeks, and continue until delivery, may be about 18% less likely to develop preeclampsia.
Who should take low-dose aspirin to prevent preeclampsia?
The American Congress of Obstetricians and Gynecologists (ACOG) have identified a number of risk factors for developing preeclampsia that make one a good candidate for low-dose aspirin.
ACOG recommends low-dose aspirin therapy for those who have one or more of the following “high” risk factors:
- History of preeclampsia, especially when accompanied by an adverse outcome
- Multifetal gestation
- Chronic hypertension
- Type 1 or 2 diabetes
- Renal disease
- Autoimmune disease (systemic lupus erythematosus, antiphospholipid syndrome)
…or more than one of the following “moderate” risk factors:
- Nulliparity (first-time mom)
- Obesity (BMI > 30)
- Family history of preeclampsia (mother or sister)
- Sociodemographic characteristics (African American race, low socioeconomic status)
- Age 35 years or older
- Personal history factors (e.g., low birthweight or small for gestational age, previous adverse outcome, more than 10-year pregnancy interval)
When and how do I take low-dose aspirin?
According to the Preeclampsia Foundation, if you meet the above criteria, it’s best to begin a low-dose aspirin regimen between 12 and 16 weeks of pregnancy, and continue right up until delivery. Certain studies also show that taking low-dose aspirin at bedtime might be the most effective time of day to take it. Aspirin should not be taken on an empty stomach.
Can I take a generic version of low-dose aspirin?
Sure can! Aspirin is aspirin, no matter the brand.
Does low-dose aspirin have any medical interactions?
Aspirin is known to interact with other medications, such as Tylenol (acetaminophen), fish oil, and different antacids. You should speak with your healthcare provider if you regularly take one of these, and are on or considering a low-dose aspirin regimen.
Are there any risks associated with low-dose aspirin?
Many authorities have investigated the potential risks of low-dose aspirin therapy, and, fortunately, it’s becoming clear that not only do the pros of low-dose aspirin therapy outweigh any theoretical risks (for those who meet the risk factor criteria), but also that the risks are pretty minimal. In fact, the United States Preventive Services Task Force found:
- No increase in infant loss, growth problems, or cognition harm to the baby;
- No statistically significant impact on risk of placental abruptions, postpartum hemorrhage (bleeding), or miscarriage to the mother;
- No differences in developmental outcomes of the infants up to age 18 months.
There are certainly risks with regular-dose aspirin, so it’s important to make sure that if you do begin an aspirin regimen, you’re taking a low dose (81 mg).
If you have a planned C-section, it’s a good idea to discuss your low-dose aspirin regimen with your healthcare provider to determine whether to stop taking it prior to the C-section.
- Hermida RC, Ayala DE, Calvo C, López JE, Mojón A, Rodríguez M, Fernández JR. “Differing administration time-dependent effects of aspirin on blood pressure in dipper and non-dipper hypertensives.” Hypertension, 2005 Oct;46(4):1060-8. Epub 2005 Aug 8. Retrieved at: https://www.ncbi.nlm.nih.gov/pubmed/16087788
- “Frequently Asked Questions About Aspirin.” The Preeclampsia Foundation. Preeclampsia.org. Last Updated on Wednesday, January 17, 2018. Retrieved at: https://www.preeclampsia.org/health-information/53-health-information/672-aspirin
- “Preeclampsia”. March of Dimes. marchofdimes.org. Last reviewed: December, 2017.
- ACOG Committee Opinion Number 743. “Low-Dose Aspirin Use During Pregnancy.” ACOG. American College of Obstetricians and Gynecologists, May 2018. Web. Retrieved at: https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Low-Dose-Aspirin-Use-During-Pregnancy?IsMobileSet=false.