Scientists from Australia and UK writing in the Lancet, say that taking aspirin during pregnancy can help cut down the risks of mothers-to-be developing pre-eclampsia.
Scientists who analyzed the results of 31 trials involving more than 32,000 women found evidence pointing to the protective effect of this drug against pre-eclampsia.
The condition, associated with high blood pressure, affects between 5% and 8% of pregnancies and may cause abdominal pain, headaches and swelling. Serious cases of pre-eclampsia kill an estimated 10 women and up to 1,000 babies each year in the UK.
The research led by Dr Lisa Askie, from the University of Sydney in Australia, showed that the risk of developing pre-eclampsia, delivering before 34 weeks, and having a pregnancy with a severely poor outcome, fell by 10% in women taking aspirin.
The same result was seen for women taking antiplatelet drugs, which like aspirin prevent blood clotting.
What causes pre-eclampsia is still unclear, but experts opine it may arise from complications that lead to irregular blood flow to the placenta, causing blood clots. This is can to lead to activation of platelets - clotting agents in the blood - and an imbalance between the hormones, which promote and slow blood flow.
Says Askie: "Our data show that antiplatelet agents produce moderate but consistent reductions in pre-eclampsia and its consequences. This information should be discussed with women at risk of pre-eclampsia to help them make informed choices about their antenatal care."
In an accompanying comment, US experts Professor James Roberts and Dr Janet Catov, from the University of Pittsburgh, wrote: "There are certain settings in which pre-eclampsia is almost a certainty, including women with pre-eclampsia in more than one pregnancy or women with chronic hypertension and pre-eclampsia in a previous pregnancy. In these settings, aspirin is justified.
"In the more usual setting of risk at about 20%, as in chronic hypertension, multiple gestations, pre-pregnancy diabetes or pre-eclampsia in one previous pregnancy, whether benefits outweigh theoretical long term risks is more difficult to judge."
The Royal College of Obstetricians and Gynecologists says the latest study findings are "very valuable".
Patrick O'Brien, a spokesman for the college, was quoted: "It is a moderate reduction of around 10 per cent, but given that pre-eclampsia is potentially serious for some women and their babies, this is an important finding.
"No single sub-group of women seems to benefit particularly from low-dose aspirin.
"The decision on whether to take it in pregnancy should be made following discussion between the woman and her obstetrician, taking into account her individual risk of developing the condition," he added.
Despite the findings, the baby charity Tommy's says it believes that not all pregnant women should routinely be prescribed aspirin. Professor Andrew Shennan says: "It's important to bear in mind that if this were the case, for every 50 women prescribed aspirin, it would only have an impact on one.
"Only pregnant women at increased risk of developing pre-eclampsia should be given aspirin during pregnancy. Risk factors range from women who've had pre-eclampsia before, those women carrying multiple pregnancies and women over 35 years of age."