DANGERS ASSOCIATED WITH MEN WHO FATHER CHILDREN AT OLD AGE - New research reveals

New studies suggest children born to older men may be at raised risk of a string of genetic disorders and diseases, including autism, schizophrenia and developmental problems such as dwarfism and cleft palate. Some have even linked having an older father to Alzheimer's disease, bipolar disorder (previously known as manic depression), heart disease and cancer.

For decades, women have been urged to have children while they're young ( 18-35) to avoid the risk of their children developing conditions associated with the mother's advancing age, such as Down's syndrome or  avoid facing a greater risk of infertility, miscarriage and health problems during pregnancy.

But now, scientists warn that a man in his 40s is twice as likely to pass down potentially disease-forming genetic mutations as a man in his 20s. In other words, the biological clock ticks for men, too.

The theory could cause a fundamental shift in sexual politics, halting the trend for older parenthood in its tracks and prompting women to think twice when choosing the men who father their children. 

And, as one expert told the Mail, we could be facing a major public health issue as more children are born with genetic disorders to parents who are not alive long enough to support them. There's no doubt that men in Britain and across the Western world are putting off fatherhood. 

One in ten British children are now born to men aged 40-44, and four per cent of all children are born to men aged 45 and over.

Experts blame the trend on the rising costs of housing and childcare, advances in fertility treatment that allow couples to 'cheat' nature - not to mention the soaring divorce rate, which means men are having second and even third marriages, and therefore often feel obliged to have children with each of their new partners.

Until now, it has largely been believed that there really were no limits on older men becoming fathers - apart, of course, from them not being around to see their children grow up.

So how exactly do older fathers pass on health problems to their children?

Just as a man's memory and skin elasticity gets worse with age, the quality of his sperm seems to as well. Crucially, unlike women who are born with a complete set of eggs, men continually make new sperm throughout their lifetime.

As a man gets older, the copying process becomes tired and less efficient and his sperm contains more mutations. And if mutated sperm is then used to form a foetus, there's more chance of problems in its development, says Professor Wilkie.Every 16 days, cells in the testicles divide and the DNA in each cell is copied into a new one which is used to make new sperm. The body is highly accurate at making an exact copy, but inevitably it sometimes makes mistakes. Some sperm will be made containing an error in the DNA - what's known as a genetic mutation.

'It's a game of chance. It may be that this mutation does not occur in a critical place. But sometimes the game of chance is against you and the mutation hits a gene that will lead or predispose your child to a certain condition.'

So if the mutation is in the gene controlling brain development, for example, it can cause autism or schizophrenia. 

And potentially if a mutation occurs in a gene affecting your risk of a type of cancer, it could increase the chances of the child getting it in later life.

Of course, children born to older parents can enjoy many advantages - research has shown they do better at school and even live longer, and often their parents can offer an emotionally and financially more stable childhood.

If the links between paternal age and health complications are true, the upward shift in the average age of fathers (and mothers) is set to have wide-reaching social and economic implications - not least because older parents, and dads in particular, will die earlier in their child's life. In the UK, a quarter of male deaths occur before the age of 65.

'When you're having children late in life, the switching of responsibility happens sooner,' says psychiatrist Dr Reichenberg. 'It's always a daunting moment when a child realises he or she will have to take care of their own parents.

'But what if that child has their own difficulties, and needs financial aid and support? If you had them later, who is going to take care of that child?

'Will future governments be dealing with this group of adults with disabilities whose parents are not there? It could become a major public health issue and it's not currently out there and being discussed.'

Dr Allan Pacey, the country's leading authority on male fertility, says it's time for a wake-up call on the dangers of putting off becoming a dad. 'I can understand why couples do it, but it's bad biology. Firstly it increases the risk of infertility, but also the evidence is fairly clear now that there are health risks.

'We haven't adequately explained all this to people so they can make an informed decision. People leave it till the eleventh hour because there's always something else to do, or a bit more of the mortgage to pay off.

'But my advice is for men to have children as young as possible - don't wait until you're in your 50s. It will make all the difference in the world to your children's health.'

(courtesy: DailyMail)