Dr Stephen D'Souza of St Mary's Hospital in Manchester and his team are to use the grant to develop their research into pre-eclampsia, a condition which causes high blood pressure and damage to blood vessels during pregnancy.

According to the BHF, it affects up to 5% of first-time mothers, usually in the last weeks of pregnancy.

Some 550 babies a year die from pre-eclampsia, usually due to suffocation. Around 10 women a year die from the condition, normally from kidney failure, strokes or fits.

Every year about 70,000 UK families are affected by the condition which may have a genetic cause.

Pre-eclampsia accounts for up to 25% of premature births in the UK.

Research has shown that low birthweight children may run a greater than average risk of developing heart disease as adults.

Blood flow

Scientists have found that women with pre-eclampsia tend to have higher levels of the gas nitric oxide in the placenta.

The gas causes blood vessels to expand.

The BHF says high levels of nitric oxide could affect how relaxed or narrow blood vessels in the placenta are and could have an impact on blood flow.

Dr D'Souza's team is looking at the role of an amino acid, called L-arginine, which is needed to produce nitric oxide.

Dr D'Souza said: "We think that one of the root causes of pre-eclampsia could be too much L-arginine being transported to the cells lining the blood vessels.

"This could lead to overproduction of nitric oxide and changes in blood pressure. If we could control the supply of L-arginine with drugs, we might have a new treatment to help save lives."

'Relatively underinvestigated'

Professor Christopher Redman, medical director of the Action for Pre-Eclampsia charity, welcomed the BHF's grant, saying pre-eclampsia was "relatively underinvestigated" considering how widespread it was.

He said L-arginine was unlikely to cause pre-eclampsia, but it could play a role in the condition.

"It is thought that one of the main origins of pre-eclampsia could be restriction in the blood supply to the placenta," he said.

"It probably develops in the first half of pregnancy before there are any visible signs."