It's usually older mums who are thought to run all the risks with later pregnancies, but a new study - albeit on mice - has found the children of older fathers have genetic changes associated with autism and other brain disorders.

Researchers at Queensland Brain Institute in Australia believe DNA from the sperm cells of older dads are more likely to develop specific mutations called CNVs, where genetic material is either deleted or repeated, than sperm that comes from younger men.

Writing in the journal Translational Psychiatry, Professor John McGrath from the Queensland Brain Institute says:

'There's quite convincing evidence now that the offspring of older dads have an increased risk of a range of brain disorders like autism and schizophrenia and maybe even slightly lower IQ. Compared to men in their early 20s, the offspring of men over age 50 have a two-fold risk of getting schizophrenia or autism.'

Prof McGrath used a mouse model to look at the genetics and examined the DNA from the young of both older and younger male mice, mated with mothers of the same age.

They found more of the CNV mutations in the offspring of the older dads. The baby mice born to older fathers also had a different shaped brain and different behaviour to those bred from younger male mice.

McGrath says the next stage will be to find CNVs in humans - something that will require expensive high throughput technology.

He wrote: 'As the studies are done in the next three to five years, we predict that the offspring of older dads will have more of these CNV.'

McGrath concluded that the study could give insight into a potentially modifiable risk factor for autism and schizophrenia and said that 'just as women are now aware that there are risks involved in delaying motherhood, then there may well be the need in the future for public health messages to men that there are risks involved in delaying parenthood.'

Do you agree? Do you think we assume that late parenthood is only a concern baby health-wise for mums?