A recent research conducted by scientists at the Mount Sinai School of Medicine, New York, and the Institute of Psychiatry, King's College London found that men who decide to have children later in life are more likely to have autistic offsprings than younger dads. They added that if the father's age influences the chances of the future child to develop autism, the same thing does not apply for women to become mothers. Namely, it does not matter what the age of a woman is when she decides to conceive and give birth to a baby, as this would have no effect on the infant's risk of autism.

The study was carried out on more than 130,000 Israeli children and the results showed that offspirngs of fathers over 40 were 6 times more likely to suffer from autism than those of fathers under 30. This leads to the conclusion that men have a "biological clock" which makes them more prone to have healthy children if they conceive them before the age of 30. Therefore, the research "provides the first convincing evidence that advanced paternal age is a risk factor for autism spectrum disorder," wrote the scientists in the Archives of General Psychiatry journal.

"This research adds to our knowledge that men also have a biological clock when it comes to reproducing. The sample size for the over-50s was small so we added it to the results for fathers aged over 40, but our research suggests that very old fathers have around nine times the risk. The research shows a linear effect - with every 10 years, the risk doubles," pointed out Dr Abraham Reichenberg, lead researcher.

Autism is a disorder of brain functioning that appears early in life, generally, before the age of three. Autistic individuals have problems with learning capacity, social interaction, communication, imagination and behavior. Autistic traits persist into adulthood, but vary in severity. Some of the adults with autism become rather normal, going to college and living on their own, while others never develop the skills of daily living.

"This phenomenon of older fathers having autistic kids should be explored further, because it might give us a clue about the genetic mechanism that contributes to the development of autism," Dr. Reichenberg concluded.