Low-dose aspirin is typically recommended to reduce the risk of developing preeclampsia in those with elevated risk. However, there are a few other scenarios that may prompt your provider to recommend or discuss low-dose aspirin with you.
Recurrent Pregnancy Loss
Low-dose aspirin may be prescribed to reduce the risk of miscarriage in the setting of recurrent pregnancy loss (2 or more pregnancy losses). Aspirin is frequently initiated before conception for this indication. The evidence for benefit from aspirin for this indication is mixed with some studies showing some benefit and others showing no benefit. Low-dose aspirin has not been found to be effective in reducing the risk of miscarriage for those without a prior pregnancy loss.
Prior Stillbirth
Although not currently recommended by the American College of Obstetricians and Gynecologist (ACOG) for the prevention of stillbirth, a meta-analysis of randomized trials found a reduction in perinatal death for aspirin doses ≥100 mg daily begun ≤16 weeks that was independent of any reduction in rates of preeclampsia and preterm birth. This benefit is thought to be related to aspirin’s effects on early placental development and function. A limitation of the analysis is that none of the trials were designed to evaluate the impact of aspirin on perinatal outcome. Additional data is needed before a strong recommendation can be made for routine aspirin use to prevent stillbirth.
COVID-19
Some providers are recommending their patients who have tested positive for SARS-CoV-2 during their pregnancy initiate low-dose aspirin. This is not a standard recommendation and it appears some providers are recommending it due to the concern for increased risk of blood clots associated with COVID-19 in pregnancy and/or the possibility for an increased risk of preeclampsia in those who have tested positive for SARS-CoV-2. While, COVID-19 does appear to be associated with an increased risk of blood clots in some patients, there is mixed data about an elevated risk of preeclampsia. Thus far there is no data on use of aspirin for these indications in pregnancy.
Low-Dose Aspirin for Preeclampsia Prevention
Depending on your risk factors, your provider may recommend taking low-dose aspirin daily to reduce your risk of developing preeclampsia.
The American College of Obstetricians and Gynecologists (ACOG) and the United States Preventive Services Taskforce (USPSTF) recommend low-dose aspirin for everyone with any one of these high risk factors:
- Previous pregnancy with preeclampsia, especially early onset and with an adverse outcome
- Type 1 or 2 diabetes mellitus
- Chronic hypertension
- Multifetal gestation
- Kidney disease.
- Autoimmune disease with potential vascular complications (antiphospholipid syndrome, systemic lupus erythematosus)
And two or more of the following moderate risk factors:
- Nulliparity (first pregnancy)
- Body Mass Index >30 kg/m2
- Family history of preeclampsia in mother or sister
- Age ≥35 years
- Sociodemographic characteristics (Black persons, lower income level [recognizing that these are not biological factors])
- Personal risk factors (eg, previous pregnancy with low birth weight or small for gestational age infant, previous adverse pregnancy outcome [eg, stillbirth], interval >10 years between pregnancies)
- IVF pregnancy
Timing and Dosing of low-dose aspirin
The American College of Obstetricians and Gynecologists (ACOG) and the United States Preventive Services Taskforce (USPSTF) recommend initiating daily low-dose aspirin between 12 and 16 weeks.
There is no consensus regarding the optimal dose of aspirin for preeclampsia prevention. In the United States, 81mg is typically recommended though some authorities have advocated a higher dose of aspirin (100 to 150 mg) daily, which is also reasonable. Because dosing between 100 to 150 mg requires cutting tablets or alternating doses, 162 mg dose (two 81 mg tablets) is one of the pragmatic options suggested by the Society of Obstetricians and Gynaecologists of Canada and others.
See also Strategies for Preeclampsia Prevention & [Explain it to Me Like I’m 5] Preeclampsia Edition
Sources
Phyllis August, MD, MPHArun Jeyabalan, MD, MSCR “Preeclampsia: Prevention” UptoDate Literature review through: Jan 2022
American College of Obstetricians and Gynecologists’ Practice Advisory: Low-Dose Aspirin Use for the Prevention of Preeclampsia and Related Morbidity and Mortality. December 2021. https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2021/12/low-dose-aspirin-use-for-the-prevention-of-preeclampsia-and-related-morbidity-and-mortality (Accessed on December 21, 2021).
Vincenzo Berghella, MDBrenna L Hughes, MD, MSc COVID-19: Overview of pregnancy issues Uptodate topic updated: Feb 11, 2022