Giving Birth with Confidence

Taking Aspirin During Pregnancy Could Prevent Preeclampsia

Cara Terreri

May is Preeclampsia Awareness Month and Lamaze International has long history of helping raise awareness with parents and professionals about preeclampsia. Today, Rebecca Britt, Community Engagement Manager for the Preeclampsia Foundation, shares the latest research about preventing preeclampsia, which is a recommendation to take a daily low-dose aspirin during pregnancy. Here's Rebecca with more information:  

According to American College of Obstetricians and Gynecologists (ACOG) and the U.S. Preventive Services Task Force (USPSTF) guidelines, pregnant people should start taking low-dose prenatal aspirin between weeks 12 and 28 of pregnancy in order to prevent preeclampsia, but recent, new evidence shows that starting taking aspirin closer to the beginning of the second trimester (at/before 16 weeks) may be more beneficial than waiting until later.

A review of 45 randomized trials that included over 20,000 pregnant women taking daily low-dose aspirin showed significant evidence of the prevention of preeclampsia, severe preeclampsia, and fetal growth restriction (where baby's growth/weight is restricted while in utero) when the women began taking low-dose aspirin before 16 weeks of pregnancy. Beginning taking low-dose aspirin after 16 weeks may not be as effective at reducing the risk of preeclampsia, severe preeclampsia, and fetal growth restriction. It's important to be screened and identified for your risk of preeclampsia and fetal growth restriciton in early pregnancy during prenatal care appointments.

When low-dose aspirin is indicated to prevent preeclampsia during the pregnancy, most studies are referring to an 81-mg daily aspirin tab, which is recommended by ACOG. Regular strength aspirin is NOT a preferred pain reliever during pregnancy.

Although there is evidence to suggest that 150 mgs of aspirin may be more effective, low-dose aspirin is generally available in the United States as 81-mg tablets and it is a reasonable dosage for prevention in people at high risk for preeclampsia.

To prevent all variations of preeclampsia including HELLP syndrome, according to USPSTF guidelines, women with one or more high-risk factors should take low-dose aspirin. Women with several moderate-risk factors may also benefit from low-dose aspirin.

Risk Factors for Preeclampsia

Low-dose aspirin is recommended if you have one or more of these high-risk factors:

  • History of preeclampsia
  • Multifetal gestation
  • Chronic hypertension
  • Type 1 or 2 diabetes
  • Renal disease
  • Autoimmune disease (systemic lupus erythematosus, antiphospholipid syndrome)

Low-dose aspirin should be considered if you have two or more of these moderate-risk factors:

  • Nulliparity (first-time pregnancy)
  • Obesity (body mass index >30 kg/m2)
  • Family history of preeclampsia (mother or sister)
  • Sociodemographic characteristics (African American race, low socioeconomic status)
  • Age ≥35 years
  • Personal history factors (e.g., low birthweight or small for gestational age, previous adverse pregnancy outcome, more than 10 years of time since last pregnancy)

If you are high or moderate risk and take low-dose low-dose aspirin you should still receive regular monitoring and response by doctors and/or midwives, and your pregnancy should be closely monitored.

Risks to Baby, Mother from Aspirin

As part of its assessment, the USPSTF considered whether there was any potential harm to parent or baby from taking daily low-dose aspirin. The report found:

  • No increase in infant loss, growth problems, or cognitive 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.
  • No studies have followed the offspring of preeclamptic women on aspirin beyond 18 months.

It’s important to note that taking aspirin does not guarantee that if you are high risk, you will not develop preeclampsia, but it’s one more thing you can do with relative safety to reduce your overall risk. The USPSTF review took into account approximately 30,000 randomized subjects, which found a 2 to 5% risk reduction in the rate of preeclampsia. Both the USPSTF and ACOG acknowledge that tools to assess individual risk for the condition and identify subgroups of mothers most likely to benefit are still needed.
 
The USPSTF authors also agreed that preventing preeclampsia could reduce medical intervention in pregnancy and delivery. Preventing poor pregnancy outcomes could also reduce post-traumatic stress disorder and postpartum depression because preeclampsia is associated with poor maternal mental health outcomes.

For more information about prenatal aspirin, visit preeclampsia.org/aspirin.

More Information 

Ask about Aspirin video

Frequently Asked Questions about prenatal aspirin

 

About Rebecca Britt

Rebecca Britt is the Community Education and Engagement Manager for the Preeclampsia Foundation. Her calling to advocate and support those who often don't have a voice led her to earn a Bachelor of Science in Social Work from the University of Vermont.

Rebecca has worked with varying populations including children in foster care, adults surviving with persistent mental illness, and women facing fertility challenges. She is passionate about reducing isolation for preeclampsia patients and survivors by building community connections and raising awareness. Her desire to demonstrate the impact of mission-focused initiatives, lead her to enroll Michigan State University where she is currently earning her Master's Degree in Program Evaluation.

Rebecca is a visionary and global thinker. She is enthusiastic about putting her passion and experience together to unite the preeclampsia community. Upholding the Preeclampsia Foundation's mission, Rebecca aims to provide the education and tools necessary to empower patients to advocate for systemic change to save lives.