America’s silent epidemic of geriatric dads…

The growing proportion of men waiting until their 40s and 50s to have children could be leading to a wave of babies born prematurely, underweight, and unhealthy.

America has been in the middle of a so-called baby bust in recent decades and the conversation has largely focused on the fact that women are increasingly waiting until they are too old to give birth, the researchers of a new study said. 

But men also apppear to have a ‘biological clock’ that eventually leads to fertility issues, said the team from Stanford University, Emory University, and the University of Rome. 

They found a link between fathers in their 40s and 50s and a variety of increased risks at birth that go beyond low birth weight and premature birth, including breathing issues, seizures, and autism spectrum disorder. 

The average age of all fathers rose steadily from 30.8 in 2011 to 32.1 in 2022, and the proportion of births involving all fathers aged 50 or older increased from 1.1 percent to 1.3 percent from 2011 to 2022, respectively. 

Researchers from the US and Italy looked at over 46 million live births in America from 2011 to 2022, with paternal age recorded for 85 percent of them.

Most fathers were under 50, and the average age was about 31. Just slightly over one percent of births were fathered by men aged 50 or older, with an average age of 53.8 in that cohort.

The researchers used records of those births to explore the relationship between paternal age and pregnancy outcomes as well as the effects on maternal health.

Fathers aged 50 to 59 had a 16 percent higher risk of fathering a baby born prematurely and a 14 percent greater risk of having a baby who is born underweight compared to fathers in their 30s.

There was also an associated 13 percent higher risk of older fatherhood resulting in the mother developing gestational diabetes during pregnancy.

Fathers in their 60s similarly showed an increased risk of causing the mother to have gestational diabetes, though this risk didn’t carry over for men in their 70s.

Men in their 70s who became fathers, meanwhile, showed a 21 percent higher chance of having a baby born prematurely and a 24 percent increased chance of the baby being underweight compared to younger fathers.

They also found that older fathers in their 50s were twice as likely to require help conceiving with assisted reproductive technology (ART) – any kind of reproductive treatment or procedure, such as IVF, used to get pregnant.

It is not clear yet, though, whether this has actually led to an uptick in babies born with conditions such as low birth weight, breathing problems, seizures, and genetic abnormalities. 

The researchers added: ‘These associations increased with advancing paternal age: fathers aged 70 years and older were more than 6 times more likely to use ART.’

Their findings were published in the journal JAMA Network Open.  

Men’s fertility tends to decrease as they age. This is due to a range of factors, such as a decrease in sperm volume of up to 3.3 percent per year and sperm’s inability to swim, and changes in the structure and shape of sperm.

While women are born with all the eggs they’ll ever have, men make new sperm cells constantly that divide and replicate around every 16 days. 

Every time those cells divide – which can happen around 800 times by the time a man reaches 50 – it introduces more chances for a genetic mutation to occur.

And a wide range of genetic conditions have been associated with advanced paternal age, including some skeletal disorders such as achondroplasia, the most common cause of dwarfism.

Older paternal age has also been associated with disorders caused by an abnormal fusion of one or more joints between the bones of a baby’s skull.

This can result in abnormal head shape and increased pressure in the skull, which can impair the baby’s brain development.

In addition to genetic disorders, older fathers have been tied to a higher risk of their children being diagnosed with schizophrenia, obsessive-compulsive disorder, autism spectrum disorder, and bipolar disorder later in life.

One study found the risk that an older father’s baby will be diagnosed with bipolar disorder down the line is 37 percent higher than that of a father in his 30s or 40s.

And an Israeli study showed a more than five-fold increase in autism risk for the children of men 40 years or older compared with those of men younger than 30.

A highly influential study in 2018 conducted by Stanford University collected data from over 40 million births and concluded not only that older fathers were more likely to have babies that were underweight and born prematurely but also that they had a higher risk of experiencing seizures.

Compared to fathers aged 25 to 34, which is the average paternity age in the US, babies born to men aged 45 or older were 14 percent more likely to be admitted to the neonatal intensive care unit, 14 percent more likely to be born prematurely, 18 percent more likely to experience seizures, and 14 percent more likely to have a low birth weight.

For fathers aged 50 or older, their newborns were 10 percent more likely to need ventilation at birth and 28 percent more likely to require care in the neonatal intensive care unit.

Older fathers are typically associated with affluence and financial stability. Prime examples include actors Robert De Niro, Al Pacino, and Billy Joel. But the researchers found that this isn’t always the case.

They cited Scandinavian research that found that older fathers come from diverse urban and rural settings, with varied education levels, marital status, and health literacy.

They added: ‘The trend toward delayed fatherhood is often attributed to diminished concerns of the male “biological clock” and the desire for educational and financial stability prior to starting a family.

‘Previous studies have also highlighted the influence of evolving gender norms that promote active parental involvement while emphasizing traditional roles like the male “breadwinner.”’

Women are also increasingly delaying childbirth despite constant awareness of this ‘biological clock,’ choosing instead in a growing number of cases to focus on professional growth and financial stability.