"Men around 40 ought to be thinking about the increased risk to their children, the same as women do," he said.

Biological clock ticks for dads too Grant McArthur

June 03, 2008 12:00am
CHILDREN born to older fathers are almost twice as likely to die before adulthood than those born to younger men, research shows.

Increased rates of birth defects, autism, schizophrenia, epilepsy and heart disease are believed to make children born to dads over 45 much less likely to live to 19 than those with fathers in their late 20s.

A Danish study of more than 100,000 children raises the prospect that biological clocks are ticking for men as sperm quality deteriorates with age.

Children born to teen fathers and over-45s are up to 88 per cent more likely to die before their 19th birthday than those born to men aged 25-29, researchers from the University of Aarhus found.

While deaths of children fathered by teens could be explained by their mothers also being young and often disadvantaged, the older men's children were only affected by their fathers' "underlying biological causes".

"The risks of older fatherhood can be very profound and it is not something that people are always aware of," said study author Jin Liang Zhu, from the Danish Epidemiology Science Centre.

The research, which tracked the children for up to the first 18 years, was published in the European Journal of Epidemiology.

Of 831 deaths, 601 were in the first year. Many were due to congenital defects.

Clinical geneticist Les Sheffield, of Melbourne's Murdoch Childrens Research Institute, said it was time fathers took responsibility for the risks.

Assoc Prof Sheffield said genetic errors in sperm increase by half a per cent when a man reaches 40, by 2 per cent when he is 50, by 5 per cent when he is 60 and by 20 per cent by the time he is 80.

"Men around 40 ought to be thinking about the increased risk to their children, the same as women do," he said.

"I speak to a lot of older parents and they talk about the women's risk, but when I talk about the father's risk they are just aghast because nobody has ever mentioned the father before," he said.