Pregnant women can be put at risk of the potentially fatal condition pre-eclampsia by their own baby’s DNA, a study has found.
The findings help to solve the puzzle of what causes pre-eclampsia, or high blood pressure during pregnancy, which can affect one in 20 expecting mothers.
Those who have it can also find they have fits and blackouts, as well as vomiting in the later stages of pregnancy.
Complications, which start in the second half of pregnancy, include high blood pressure, swollen feet, hands and face as well as stomach pain.
While blood pressure treatments can help, the most effective solution is to deliver the baby.
The findings help to solve the puzzle of what causes pre-eclampsia, or high blood pressure during pregnancy, which can affect one in 20 expecting mothers
While it was known that the condition is often inherited, scientists have now identified genes carried by the baby which is causing their mothers to get ill.
Hope for the future
It is hoped that by knowing more about the genes it will enable doctors to identify mothers most at risk.
The placenta – the organ that attaches the foetus to the mother’s womb – is created by the baby.
Certain genes can mean the placenta leaks. The result is a protein produced in the placenta that is meant to help the foetus grow ends up in the mother’s bloodstream.
This can damage blood vessels, and other organs, causing the heart to pump harder, increasing blood pressure.
What did the researchers say?
We found there were indeed some features in a baby’s DNA that can increase the risk of pre-eclampsia
Dr Linda Morgan, from the University of Nottingham
Dr Linda Morgan, from the University of Nottingham’s School of Life Sciences, coordinated the 5-year study, which included DNA samples contributed from Iceland, Norway and Finland as well as from over 20 universities and maternity units in the UK.
Dr Morgan said: ‘For many years midwives and obstetricians have known that a woman is more likely to develop pre-eclampsia if her mother or sister had the disorder.
‘More recently research has shown that the condition also runs in the families of men who father pre-eclamptic pregnancies.
‘We knew that faulty formation of the placenta is often found in pre-eclampsia. As it is the baby’s genes that produce the placenta we set out to see if we could find a link between the baby’s DNA and the condition.
‘We found there were indeed some features in a baby’s DNA that can increase the risk of pre-eclampsia.’
Dr Linda Morgan, from the University of Nottingham, said: ‘We found there were indeed some features in a baby’s DNA that can increase the risk of pre-eclampsia’
How was the study carried out?
Analysis of the genes of babies whose mothers suffered pre-eclampsia were analysed and compared to babies whose mothers did not suffer the condition.
The researchers identified the protein that is causing the damage: called sFlt-1.
When released from the placenta into the mother, the protein causes damage to blood vessels, as well as the kidneys, liver and brain.
THE TEST TO STOP PREMATURE BIRTHS
Pregnant women with pre-eclampsia could be spared from needlessly having their baby delivered prematurely, thanks to a test developed by UK doctors.
Queen Mary University of London researchers made a series of tests, which when analysed with a computer programme can tell with 84 per cent accuracy whether a mother is at immediate risk.
This enables them to make an informed decision about whether to deliver the baby or whether the mother can safely be discharged and just monitored for problem.
The programme, funded by the research arm of the NHS and tested in 50 UK hospitals, is now to be turned into a smartphone app, enabling it to be widely used.
Babies with variations of the genes that produce this protein were more likely to be pre-eclampsic.
‘First piece of the genetic jigsaw’
Dr Ralph McGinnis, who led the analysis at the Sanger Institute, said: ‘Pre- eclampsia has been recognized since ancient Egypt and Greece as being a danger to the lives of mothers and babies.
‘This first piece of the genetic jigsaw holds substantial promise for unlocking some of the mystery of how pre-eclampsia is caused.
‘Our finding may also enable better prediction of mothers who will become pre-eclamptic when combined with clinical information and with other pieces of the genetic jigsaw that will also surely be discovered in the next few years.’
Over 50 per cent of people carry the gene sequence that can lead to the placenta becoming faulty.
Dr Morgan added: ‘Because pre-eclampsia has its origins in the very early stages of pregnancy, during the formation of the placenta, research into the causes and processes of the disease has always been challenging.
‘Now modern genome wide screening and its data analysis allows us to look for clues in the mother’s, father’s and their baby’s DNA.
‘We believe the new insights from this study could form the basis for more effective prevention and treatment of pre-eclampsia in the future, and improve the outcome of pregnancy for mother and child.’
The main risk factors for preeclampsia are multiple pregnancy, a history of chronic high blood pressure, diabetes, kidney disease or organ transplant, first pregnancy or obesity. Around 38,000 mothers in the UK suffer from the condition every year.