A small dose of aspirin in pregnancy can help prevent high blood pressure complications such as pre-eclampsia the biggest cause of maternal death in the UK, according to new guidance.
The National Institute for Health and Clinical Excellence says women at risk need aspirin from the 12th week of pregnancy until the birth of the child.
Up to 5% of first-time mothers will develop pre-eclampsia, and its prevalence is on the rise because more women are delaying pregnancy until they are older and more are also overweight
High blood pressure in pregnancy can also lead to premature birth, stillbirth and babies being smaller than average.
Low-dose (75mg) aspirin is not routinely given to pregnant women and NICE hopes the advice will ensure consistent standards across the country.
Fergus Macbeth, director of the centre for clinical practice at NICE, said: "Hypertension, or high blood pressure, can be fairly common and can develop at any time during pregnancy. If not properly managed, it can cause serious health problems.
"That's why it's important that women who are pregnant or planning a pregnancy and who have either been diagnosed or identified as being at risk of developing a form of hypertension, receive a consistent, high standard of antenatal and postnatal care to prevent problems occurring."