Many pregnant women are surprised when their doctor prescribes aspirin. However, in obstetrics it is used in very low doses and for a specific purpose. So why might an expectant mother need aspirin?
First of all — to help prevent preeclampsia and fetal growth restriction. In low doses, acetylsalicylic acid improves blood flow in the vessels of the uterus and placenta, helping the placenta function more effectively. It is important to understand that the risk of preeclampsia is assessed not only through combined screening, but also through a risk calculator that includes both high- and moderate-risk factors.
Who is aspirin recommended for first?
If there is at least one high-risk factor:
• preeclampsia in a previous pregnancy
• chronic hypertension
• kidney disease
• type 1 or type 2 diabetes
• autoimmune diseases (for example systemic lupus erythematosus or antiphospholipid syndrome)
• multiple pregnancy (twins or more)
Or several moderate-risk factors:
• first pregnancy
• age 35+
• obesity (BMI ≥30)
• preeclampsia in the mother or sister
• pregnancy after IVF
• interval between pregnancies longer than 10 years
Important: aspirin reduces risk but does not provide a 100% guarantee.
When should it be started and how long should it be taken?
The best effect is achieved if aspirin is started between 12 and 16 weeks of pregnancy and continued until 36 weeks. In some situations, treatment may continue until delivery and even during breastfeeding. The exact dose should always be determined by a doctor.
Is aspirin dangerous for the baby?
No. Numerous studies have shown that low-dose aspirin is safe during pregnancy. Moreover, the risk of not taking aspirin when it is indicated may be higher than taking it. Missing the opportunity to prevent preeclampsia and fetal growth restriction can be dangerous for both the mother and the baby.