The lives of more than 125,000 women born with heart disease are at risk during pregnancy, experts warn today.

About 6,000 children are born with heart disease every year, but there is no long-term cure. And later in life, women with congenital heart disease are 100 times more likely to die during pregnancy than others, specialists say.

The warning comes as leading heart and pregnancy doctors at the Royal Brompton and Harefield NHS Trust and Chelsea and Westminster Healthcare NHS Trust publish a report on the problems faced by these women.

Improvements in medical and surgical treatment mean that more than 85 per cent of babies born with heart disease survive into adulthood. But the experts warn that most adult patients with congenital heart disease are not aware that they need continuous specialist care, or that they face greater risks during pregnancy.

Michael Gatzoulis, professor of cardiology and adult congenital heart disease at Royal Brompton Hospital and one of the authors of the report, said: "Mothers with congenital heart disease are, on average, 100 times more likely to die during pregnancy than other pregnant women.