The devastating impact of asphyxia at birth, which affects more than 1,000 babies a year in the UK, can be averted by applying a hi-tech version of an ice pack to the head, doctors have found.
Cooling the brains of newborn babies deprived of oxygen dramatically improves the proportion who survive unharmed, two decades of research has shown.
Brain damage in babies asphyxiated at birth – often because their umbilical cords have become wound around their necks – leaves hundreds permanently disabled each year and is the most common cause of multimillion-pound lawsuits against the health service.
A study of babies asphyxiated at birth in hospitals across the UK and Europe suggests that the cooling treatment could save at least 100 babies a year from brain damage.
Of the 325 babies in the survey, half were cooled within six hours of delivery and their body temperatures were maintained at 3C to 4C below normal for three days. The results showed that almost half (44 per cent) recovered with no brain damage, compared with just over a quarter (28 per cent) among those left at normal temperature.
Denis Azzopardi, of Imperial College, London, who led the research published in the New England Journal of Medicine, said: "Our study builds on a 20-year body of research but gives, for the first time, irrefutable proof that cooling can be effective in reducing brain damage after birth asphyxia. Unfortunately, it doesn't work in every case.
"Birth asphyxia is a very important problem, even in the UK which has a fantastic obstetric service. Cases still occur and there are about 1,400 infants born with birth asphyxia each year in the UK. Worldwide it is a huge problem."
The findings of the £1m study will be passed to the National Institute for Clinical Excellence for consideration.
Cooling the brain to reduce damage caused by injury was tried on soldiers in the 19th century, and as a means of resuscitating babies in the 1950s (by plunging them into very cold water). The new research shows there is a "therapeutic window" of a few hours after injury occurs when it is possible to intervene to prevent long-term damage.
Dr Azzopardi added: "Injury caused by asphyxia occurs in two phases: immediately, when the brain is starved of oxygen, and then later when the blood supply is restored and there is a chemical cascade when the machinery of the cells breaks down."
To have maximum effect, cooling must begin within six hours of birth and be maintained for 72 hours before an infant is gradually warmed again. Different techniques have been used. One involves the use of a polythene "coolcap" hat filled with cold water, or, for the current study, a total body version involving pumping cold water through a specially adapted mattress.
"It is not a new concept. The rationale is relatively simple. But of all the treatments for brain damage tried, cooling has proved the most effective," Dr Azzopardi said.
Carmel Bartley, of the children's charity, Bliss said: "This is welcome research into an area which is known to save lives. It is a specialist treatment we would like to see used more widely."