For women at high risk of preeclampsia, start taking one low-dose aspirin tablet daily after week 12 of pregnancy

5. For women at high risk of preeclampsia, start taking one low-dose aspirin tablet daily after week 12 of pregnancy

Cost: A few dozen yuan. One tablet per day must be taken until delivery. The hard part is remembering to take it every single day.

In plain terms: Preeclampsia is a type of high blood pressure that occurs during pregnancy. Women falling into any of these six categories are at high risk: those who had preeclampsia in a previous pregnancy, women carrying multiples, women with chronic hypertension, women with diabetes prior to pregnancy, women with kidney disease, and women with autoimmune diseases. For these women, taking one low-dose aspirin tablet daily starting at week 12 can reduce the risk of preeclampsia by roughly 15%, the risk of premature birth by about 20%, and the risk of perinatal death by nearly 20%. Women not in these categories should not take it on their own.

Benefit: The US Preventive Services Task Force gives this a Grade B recommendation: for women at high risk of preeclampsia, taking low-dose aspirin (81 mg per day) after week 12 of pregnancy can help prevent the condition. Preeclampsia is a hypertensive disorder unique to pregnancy. Results from multiple studies combined show the following outcomes, with 95% confidence intervals provided as ranges of reliability. The relative risk of preeclampsia drops to 0.85 (95% CI: 0.75 to 0.95, based on 16 studies), a reduction of roughly 15%. The relative risk of premature birth is 0.80 (95% CI: 0.67 to 0.95, based on 13 studies), a drop of about 20%. The relative risk of perinatal death — death occurring around the time of childbirth — is 0.79 (95% CI: 0.66 to 0.96, based on 11 studies), a reduction of roughly 21%. The relative risk of small-for-gestational-age infants or intrauterine growth restriction is 0.82 (95% CI: 0.68 to 0.99, based on 16 studies), a decrease of around 18%, meaning fetuses are less likely to be smaller than expected for their gestational age.

Evidence grade: A

Notes: The groups considered high risk include women who had preeclampsia in a prior pregnancy, those carrying twins or multiples, women with chronic hypertension, women with type 1 or type 2 diabetes prior to pregnancy, women with kidney disease, and women with autoimmune diseases such as systemic lupus erythematosus or antiphospholipid syndrome. Women not in these groups should not take aspirin on their own. This medication requires a doctor’s prescription; be sure to share your full medical history during prenatal checkups so your doctor can make an appropriate assessment. Most low-dose aspirin tablets sold in China are 100 mg enteric-coated tablets, and they must be taken strictly as directed by your doctor.

Sources: 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>