Aspirin during pregnancy could reduce risk of pre-eclampsia

May 20 2007

Women who receive aspirin or other antiplatelet drugs during pregnancy are at lower risk of pre-eclampsia, conclude authors of an article published in an upcoming edition of The Lancet.

Pre-eclampsia is a multisystem disorder of pregnancy that is usually associated with high blood pressure and proteinuria (excess of serum proteins in the urine).

Dr Lisa Askie, from the University of Sydney's School of Public Health, with funding from the Australian National Health and Medical Research Council, along with colleagues from Australia and the UK, formed the Perinatal Antiplatelet Review of International Studies (PARIS) collaborative group and did a meta-analysis (a study which combines the results of previous trials) on more than 32 000 women and their babies.

They found that the risks of developing pre-eclampsia, of delivering before 34 weeks and of having a pregnancy with a severe adverse outcome all fell by 10 per cent in those women taking aspirin or other antiplatelet drugs.

Aspirin was found to have 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. No particular subgroup of women was substantially more or less likely to benefit from aspirin than any other.

The cause of pre-eclampsia remains unclear, although it is known that complications in the maternal spiral arteries in early pregnancy can lead to irregular blood flow to the placenta, causing blood clots in and death to placental tissue.

This can lead to activation of the platelet and clotting system and an imbalance betweenhormones which promote and slow blood flow. Antiplatelet agents such as aspirin are thought to prevent pre-eclampsia by redressing this balance.

The authors conclude: “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.”