Women who use the contraceptive pill for years risk a build-up of plaque in their arteries, according to a study released this week.

While the European study suggests long-term pill users may therefore be at increased risk of heart attack or stroke, the researchers say their findings are no need for alarm.

"Bottom line - don't discontinue your pill suddenly. Don't panic. Don't call your gynaecologist tomorrow morning," says lead researcher Dr Ernst Rietzschel of Ghent University in Belgium, whose team presented the results at an American Heart Association meeting this week.

Rietzschel's team studied 1301 women aged 35-55. Of these, 81% had used the pill for an average 13 years.

The researchers measured plaque levels using a technique called vascular echography.

They saw a rise of 20-30% in arterial plaque in two big arteries - the carotid in the neck and the femoral in the leg - for each decade of use.