The NHS is to roll out a new test for pregnant women after research found it could diagnose a potentially lethal condition half as quickly as current methods.

The checks for pre-eclampsia – which affects around one in 10 pregnancies – will be rolled out across the health service, following the study published in The Lancet.

The condition, linked to high blood pressure in pregnancy, normally occurs late in pregnancy, when it can compromise the health of both mother and baby.

Normally, it is uncovered by a combination of blood pressure checks and urine tests, but this can take several days, while risks are increasing.

The research by Kings College London, involving more than 1,000 pregnant women, found that a blood test could identify pre-eclampsia in 1.9 days compared with the 4.1 days it takes using traditional methods. This brought down serious complications before birth – such as eclampsia, stroke and maternal death – down from 5 per cent to 4 per cent.