Tick tock. Men also have a biological clock.

It’s not just the age of the mother-to-be we should be concerned about when it comes to having children. New research shows that dads too have a biological clock.

The study, published in the America Journal of Stem Cell Research, shows that fathers over the age of 40 are five times more likely to have a child who suffers from autism than fathers 30 years and under.

Joanna Kitlinska, head researcher from Georgetown University Medical Centre, says, “We know the nutritional, hormonal and psychological environment provided by the mother permanently alters organ structure, cellular response and gene expressions in her offspring. But our study shows that the same thing is true of fathers- his lifestyle, and how old he is, can be reflected in molecules that control gene function.”

The study also found that a father’s alcohol consumption can affect unborn babies. Heavy drinkers increase the risk that their babies will be diagnosed with foetal alcohol spectrum disorder (FASD), a condition previously thought only to be the result of mothers drinking during pregnancy.

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Babies born with FASD can suffer from abnormal facial features, such as a smooth ridge between the nose and upper lip, small head size, shorter-than-average height, low body weight, poor coordination, hyperactivity, difficulty with attention, poor memory, learning disabilities, speech and language delays, intellectual disability or low IQ, poor reasoning and judgment skills, sleep and sucking problems as a baby, vision or hearing problems and problems with the heart, kidneys, or bones.

The new research has shown that in over 75 per cent of the cases assessed, the baby’s fathers were heavy drinkers.

Fathers over the age of 40 are five times more likely to have a child with autism. Image: istock

The information is interesting because until now much of the babies' health was attributed to the mother.

"We know that the nutritional and psychological environment a mum provides can alter an offspring's organ structure," Joanna Kitlinska told The New York Post.

"Our study shows that a father's lifestyle can also be reflected in his offspring's gene function."

The same research also found that lifestyle factors such as obesity were linked with babies who developed diabetes, obesity and brain cancer.

Featured image via Instagram.