Men should consider freezing their sperm at the age of 18 to reduce the chance of having a disabled child, a British expert has suggested.

The risk of having a child with disorders such as autism and schizophrenia increases the older a father gets, emerging research suggests.

This is thought to be linked to the quality of a man’s sperm, which deteriorates with age.

Dr Kevin Smith, a bioethicist at Abertay University in Dundee, today called for the NHS to offer all young men free sperm banking, so they can store high-quality sperm until they are ready to be fathers.

Freezing facilities in private sperm banks do exist – but cost up to £200 a year.

Because the quality of sperm declines with age, men 'should be able to freeze it for free at the age of 18'

Dr Smith said a public health campaign is needed, to raise awareness of the problem – and warned that if nothing is done there would be a gradual reduction of ‘human fitness in the long term’.

Fertility doctors, however, greeted the controversial suggestion as ‘crackers’ – and accused Dr Smith of promoting an unnecessarily artificial approach to parenthood.

They said the risks of older fatherhood are small – and do not kick in until well into the 40s.

But Dr Smith, writing in the respected Journal of Medical Ethics, said: ‘In principle, it would be straightforward for young men (aged perhaps 18) to elect to have their sperm stored until starting a family at an older age, thus avoiding a build-up of new mutations.’

‘If you’re a man and you know there’s a risk that your age will increase the chances of your child having a genetic disorder, you may want to know what the best age for you to have children at is in order to reduce the risk of a genetic disorder developing in your offspring.

‘From the evidence that has come to light over the past few years it is clear that earlier fatherhood is desirable in terms of maximising genetic integrity.’

The average age of fatherhood in England and Wales increased from 31 in the early 1990s to nearly 33 by 2013, according to the Office for National Statistics.

Dr Kevin Smith, a bioethicist at Abertay University in Dundee, today called for the NHS to offer all young men free sperm banking, so they can store high-quality sperm until they are ready to be fathers

Dr Smith said: ‘The risks associated with delayed fatherhood are not at present widely known and, from an ethical perspective, those considering parenthood must be made aware of these risks so that they can make a properly informed decision.

‘Although it would require a change in what we as society currently think is acceptable, this could easily be solved with a public health campaign. These have been successful in the past – for example where the link between smoking and low birthweight was established.’

He conceded that not all would welcome his idea.

‘This approach may appear radical or intuitively unwelcome to some, in that it would entail a wholescale move away from natural conception,’ he said.

But he added: ‘Sperm banking is a practical solution that could in principle be implemented immediately.’

The risk of having a child with disorders such as autism and schizophrenia increases the older a father gets, emerging research suggests (file pic)

Others disagreed, however. Professor Adam Balen, chairman of the British Fertility Society, said: ‘This move would provide a very artificial approach to having babies.

‘Procreation should not be taken out of the bedroom and into the test-tube unless there are defined fertility problems.

‘There should be a greater focus in the UK on supporting young couples to establish their careers and relationships and be supported in having children at a young age before the natural decline in both female and male fertility.’

Professor Allan Pacey, a leading expert in male fertility at the University of Sheffield, added: ‘This is one of the most ridiculous suggestions I have heard in a long time.

‘The idea that mass sperm banking for 18-year-olds should be funded by the NHS is simply crackers, in my opinion.

‘We know that the sperm from the majority of men won't freeze very well, which is one of the reasons why sperm donors are in short supply.

‘Therefore, men who froze their sperm at 18, and returned to use it later in life, would essentially be asking their wives to undergo one or more IVF procedures in order to start a family.’