Fenton is at a special baby unit at a London hospital.'McCready and Daughter' is on BBC1 tonight at 8.10pm. An early test for one of the most dangerous complications of pregnancy promises to save hundreds of babies each year who would otherwise die from pre-eclampsia, which causes convulsions and premature births. An early test for one of the most dangerous complications of pregnancy promises to save hundreds of babies each year who would otherwise die from pre-eclampsia, which causes convulsions and premature births. Scientists said yesterday the test can identify women at risk of pre-eclampsia as early as nine weeks into pregnancy, leading to better treatment and care of women and their unborn children who would otherwise develop the more severe symptoms of the disorder.Pre-eclampsia results from an irregular blood supply to the foetus, causing raised blood pressure and convulsions in the mother. It affects one in 10 first pregnancies, resulting in the deaths of 600 babies and 10 women each year in Britain.The test, being developed by a team of researchers led by Professor Philip Lowry of Reading University, relies on the identification of a key protein called neurokinin B (NKB), which is produced by the placenta and is secreted in high concentrations into the bloodstream of women developing pre-eclampsia.

Professor Lowry said NKB is usually found only in the brain where it acts as a signalling molecule, sending messages between nerves.Its role in the placenta appears to be in the control of the blood supply between the foetus and the mother. "NKB probably corrects the blood flow between the placenta and the uterus. When the blood supply is corrected, levels of NKB drop and the pregnancy progresses normally," Professor Lowry said. "Only when problems arise do the signals come out of the placenta and then get into the mother's circulatory system."As the mother's blood pressure rises in response to problems with the placenta, more NKB is produced, which can, at high enough concentrations, lead to pre-eclampsia, Professor Lowry said.Rising blood pressure causes valuable blood proteins to leak through the kidneys into the urine, while waste products are retained. The most dangerous complications are blood clots on the brain, fluid in the lungs, kidney and liver damage and convulsions.Detecting raised levels of NKB would enable doctors to identify mothers at an early enough stage to give the preventive treatment and so delay the need for an early delivery.

The research, published in the journal Nature, might also lead to the development of drugs that can block the effect of NKB, thereby preventing the onset of pre-eclampsia.Currently the only effective treatment is to deliver the baby early by Caesarean section, which increases other health risks.Jacqui Jablaoui, director of Action on Pre-eclampsia, said any early diagnostic test was welcomed. "All women should have access to anything that increases the chances of having a healthy baby. But a trial that shows it can work can still take many years," she said. "These are still preliminary results and I wouldn't want to raise people's hopes too much."Professor Lowry said a handful of medical centres dealing with pre-eclampsia will soon begin trials of the test, which he hopes will be made generally available within the next two years "It'll be as common as the pregnancy test itself," he said..