A University of Sydney team analysed data on more than 32,000 women for a study published in The Lancet. The results suggested cases of pre-eclampsia, which is caused by a defect in the placenta, could fall by 10% if aspirin was taken widely. But experts urged caution, given the small risks linked to long-term aspirin use.
Pre-eclampsia can trigger high blood pressure and kidney problems. It affects approximately 7% of pregnancies, and, if uncontrolled, can increase the chances of both mother and baby dying. Although up to 35% of premature births in the UK are connected to the condition, the precise reason it develops is unknown.
Pre-eclampsia is known to cause excessive blood clotting in the placenta, which supplies nutrients and oxygen to the foetus, and various experts have suggested that aspirin, which inhibits clotting, could counter this.
The main health risk found by other studies to be associated with aspirin is an increased chance of bleeding, which is potentially a serious issue within pregnancy and birth. However, the study found no evidence that taking aspirin long term might be linked to bleeding problems at any stage, although the researchers said that their evidence was not strong enough to rule this out entirely.
Overall, they said, the potential benefits of taking the drug might outweigh the risks, particularly in women at higher risk of pre-eclampsia, such as overweight or older mothers, or those with a previous or family history of the condition.
Mike Rich, chief executive of charity Action on Pre-Eclampsia, said the study would help spread the message about the potential benefits of aspirin to a wider audience of doctors. He said: “Under no circumstances should pregnant women self-medicate with aspirin. While this study suggests that aspirin can have benefits to women at high risk, the decision to use aspirin should only be made in consultation with your doctor.”