Taking aspirin or other antiplatelet drugs throughout pregnancy could reduce the risk of developing pre-eclampsia, a condition that raises blood pressure and can lead to strokes and even death.
A University of Sydney team along with colleagues from Australia and the UK, formed the Perinatal Antiplatelet Review of International Studies (PARIS), conducted a meta-analysis examining data from 31 studies on more than 32,000 women.
They found that the risks of developing pre-eclampsia could fall by 10 per cent if aspirin was taken widely.
They also found that women who took the drug were 10 per cent less likely to have a very premature baby and serious pregnancy complications or to deliver before 34 weeks.
The report is published in The Lancet medical journal.
The effect was found in trials where low-dose 75mg aspirin (around half a tablet) was used, and higher doses up to around 150mg. No particular subgroup of women was substantially more or less likely to benefit from aspirin than any other.
The aspirin had no significant effect on the risk of death of the fetus or baby, having a small-for-gestational-age infant, or bleeding events for either the women or their babies.
"Our data shows that antiplatelet agents produce moderate but consistent reductions in pre-eclampsia and its consequences," said Dr Lisa Askie of the University of Sydney, the lead researcher in the study.
But in an accompanying comment, experts urged caution given the risks linked to long-term use of aspirin or other antiplatelet drugs. Women should consult their doctors before taking aspirin during pregnancy.
About one in 12 pregnant mothers are affected by pre-eclampsia, which is caused by a defect in the placenta. The only treatment is to deliver the baby early with an emergency caesarean.
Complications in maternal arteries in early pregnancy can lead to blood clots in and death to placental tissue. This can lead to activation of the clotting system and an imbalance between hormones which promote and slow blood flow. Antiplatelet agents such as aspirin are thought to prevent pre-eclampsia by redressing this balance.
