If you are at high risk of preeclampsia, ask your clinician about low-dose aspirin after 12 weeks
Preeclampsia is a hypertensive disorder of pregnancy. Risk factors include a previous affected pregnancy, multiple pregnancy, chronic hypertension, pre-existing diabetes, kidney disease, and certain autoimmune diseases. For high-risk patients, prescribed low-dose aspirin after 12 weeks reduces preeclampsia by about 15% and preterm birth and perinatal death by about 20% in pooled studies. Do not start it on your own.
What it takes
Typically tens of RMB in China. It requires a daily prescribed dose through the period your clinician recommends; the source describes continuation until delivery.
What you may gain
The US Preventive Services Task Force gives a grade B recommendation for low-dose aspirin, 81 mg/day, after 12 weeks of gestation in people at high risk of preeclampsia. Pooled estimates were RR 0.85 for preeclampsia, 95% CI 0.75–0.95 across 16 studies, about a 15% reduction; RR 0.80 for preterm birth, 95% CI 0.67–0.95 across 13 studies, about 20%; RR 0.79 for perinatal mortality, 95% CI 0.66–0.96 across 11 studies, about 21%; and RR 0.82 for small-for-gestational-age birth or intrauterine growth restriction, 95% CI 0.68–0.99 across 16 studies, about 18%. Perinatal mortality concerns deaths around birth; growth restriction means a fetus grows less than expected for its gestational age.
Context & considerations
High-risk factors include previous preeclampsia, twins or higher-order multiples, chronic hypertension, pre-existing type 1 or type 2 diabetes, kidney disease, systemic lupus erythematosus, and antiphospholipid syndrome. Discuss the full history at antenatal care so a clinician can decide. The source emphasizes avoiding self-medication outside these categories. Enteric-coated 100 mg tablets are common in China; use the prescribed dose rather than assuming the US 81 mg formulation is interchangeable tablet for tablet.
Research & references
US Preventive Services Task Force (2021). Aspirin Use to Prevent Preeclampsia and Related Morbidity and Mortality: Preventive Medication. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/low-dose-aspirin-use-for-the-prevention-of-morbidity-and-mortality-from-preeclampsia-preventive-medication