File picture (Reuters)

A new blood test could predict from the earliest stage of pregnancy whether a woman will go on to suffer a miscarriage.

The test, carried out in the first 12 weeks of pregnancy, can also predict if a woman is at risk of giving birth prematurely or developing pre-eclampsia, a potentially fatal condition causing high blood pressure.

Researchers discovered molecules in the blood that predict these birth complications with up to 98 per cent accuracy. More research is needed before the test could be rolled out – but the findings have been hailed as ‘very promising'.

Being able to establish if a woman is at risk of such conditions could allow doctors to act early to prevent them. Around one in four women in the UK suffer a miscarriage, while complications including pre-eclampsia and premature birth can cause long-term damage to both mother and baby.

Until now, prevention has been a ‘significant challenge' as symptoms generally only appear in the second to third trimesters – from the 13th week of pregnancy.

But the US scientists said the underlying problems are thought to start as early as the first week of pregnancy in the placental bed – a membrane that connects the mother's blood vessels to the placenta.

They found signs of future problems could be detected in the first trimester – the first 12 weeks – before symptoms appeared. The blood test screens for molecules called microRNA, which are found in blood cells in the placental bed. These are thought to indicate problems with blood supply, which can trigger birth complications.

The team, from the Laboratory for Reproductive Medicine and Immunology in San Francisco, presented their findings to the annual congress of the American Society for Reproductive Medicine (ASRM) in San Antonio, Texas. They looked at 160 pregnancies, of which 101 had no complications while the others were affected by miscarriage, early onset pre-eclampsia and premature birth.

Examining microRNA at various points during pregnancy, they found accuracy rates typically ranged between 90 and 98 per cent for predicting all the conditions except for pre-eclampsia, which was 82 per cent accurate.

The authors, led by Edward Winger, wrote in their research summary: ‘These complications pose a serious risk to both maternal and infant health. Our analysis supports the idea that [they] have a common biological origin early in the first trimester that can be detected throughout the first trimester. Ours is the first to use microRNA to successfully predict multiple pregnancy disorders with high specificity.'

Professor Simon Fishel, an IVF pioneer and managing director of fertility clinic Care Fertility, said the finding could help save some pregnancies, adding: ‘Obstetricians have means to help manage such disorders and early recognition of these complications is vital. Further support and evidence for this biomarker could indeed be an important tool in the management of these high risk pregnancies.'

He said that if microRNA is a warning of blood flow problems, potential treatments could include blood-thinning drugs such as heparin.

Tim Child, associate professor of obstetrics and gynaecology at Oxford University, called for more research, saying the numbers in the study were ‘quite small' and it is ‘not at the stage yet where you could start to us it as a clinical tool'.

But he added: ‘The statistical relationship is very, very strong – surprisingly strong, to be honest. It's certainly very promising.'

Barbara Hepworth-Jones, of the Miscarriage Association, said: Much research is still needed ... but this holds real hope for the future.'