LONDON - CHILDREN are almost twice as likely to die before adulthood if they have a father over 45, research has shown.

A mass study has found that deaths of children fathered by over-45s occurred at almost twice the rate of those fathered by men aged between 25 and 30.

Scientists believe that children of older fathers are more likely to suffer particular congenital defects as well as autism, schizophrenia and epilepsy.

The study was the first of its kind of such magnitude in the West, and researchers believe the findings are linked to the declining quality of sperm as men age.

Altogether, 100,000 children born between 1980 and 1996 were examined, of whom 830 have so far died before they reached 18, the majority when they were less than a year old, the London Telegraph reported.

The deaths of many of the children of the older fathers were related to congenital defects such as problems of the heart and spine, which increase the risk of infant mortality.

But there were also higher rates of accidental death, which the researchers believe might be explained by the increased likelihood of the children suffering from autism, epilepsy or schizophrenia.

Most research into older parents has, until now, focused on the risks passed on by older mothers. But the new study, published in the European Journal of Epidemiology, was adjusted to take account of maternal age and socio-economic differences.

Previous research using the same data found that older men were four times as likely to father a child with Down's syndrome, while other studies have found that the genetic quality of sperm deteriorates as men age.

More than 75,000 babies in Britain are born to fathers aged 40 and over each year, or more than one in 10 of all births. This includes more than 6,000 born to fathers aged 50 or over. The average age of fathering a child in Britain is 32.

Dr Allan Pacey, senior lecturer in andrology - the medical specialty dealing with male reproduction - at the University of Sheffield, said: 'A lot of people know that there are risks for the child that come from having an older mother, but children of older fathers also carry an increased risk.

'These sorts of results provide another good reason to have children early, when possible.'