Aspirin in prevention of pre-eclampsia

Advice regarding use of aspirin in pregnancy to reduce risk of preeclampsia has been outlined by NICE (1)

Advise pregnant women at high risk of pre-eclampsia to take 75-150 mg of aspirin [*] daily from 12 weeks until the birth of the baby.

Women at high risk are those with any of the following:

• hypertensive disease during a previous pregnancy
• chronic kidney disease
• autoimmune disease such as systemic lupus erythematosus or antiphospholipid syndrome
• type 1 or type 2 diabetes
• chronic hypertension

Advise pregnant women with more than 1 moderate risk factor for preeclampsia to take 75-150 mg of aspirin[*] daily from 12 weeks until the birth of the baby. Factors indicating moderate risk are:

• first pregnancy
• age 40 years or older
• pregnancy interval of more than 10 years
• body mass index (BMI) of 35 kg/m2 or more at first visit
• family history of pre-eclampsia
• multi-fetal pregnancy

[*] Although this use is common in UK clinical practice, at the time of publication (June 2019), aspirin did not have a UK marketing authorisation for this indication. Community pharmacies cannot legally sell aspirin as a pharmacy medicine for prevention of pre-eclampsia in pregnancy in England. Aspirin for this indication must be prescribed. The prescriber should see the summary of product characteristics for the manufacturer's advice on use in pregnancy. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. Informed consent should be obtained and documented. See the General Medical Council's Prescribing guidance: prescribing unlicensed medicines for further information.

A systematic review (2) concluded that:

• daily low-dose aspirin during pregnancy was associated with lower risks of serious perinatal outcomes for individuals at increased risk for preeclampsia, without evident harms

Reference:

• NICE (June 2019). Hypertension in pregnancy: diagnosis and management
• Henderson JT, Vesco KK, Senger CA, Thomas RG, Redmond N. Aspirin Use to Prevent Preeclampsia and Related Morbidity and Mortality: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2021;326(12):1192-1206. doi:10.1001/jama.2021.8551