Men Have Biological Clocks Too, Study Warns

Most women understand that having children later in life can involve risks. Men, however, are generally far less aware of them.

Despite this imbalance, a review spanning 40 years of medical literature has concluded that men have “biological clocks” too. If those clocks run on for too long, they may create health risks for both their partners and their children.

Male biological clocks and conception

“While it is widely accepted that physiological changes that occur in women after 35 can affect conception, pregnancy and the health of the child, most men do not realize their advanced age can have a similar impact,” says study author Gloria Bachmann, director of the Women's Health Institute at Rutgers University.

Bachmann and her team identified a decline among men older than 45. Age seemed to influence the time it took for men to conceive with their partners, including when the partner was considerably younger.

Where pregnancy did occur, sperm from older men was associated with a greater number of complications. A study examining outcomes from more than 40 million live births over a decade found that older fathers increased a pregnant woman’s risk of pre-eclampsia, gestational diabetes and premature birth.

The effects may continue as the child develops. That same research reported higher risks of newborn seizures, low birth weight and admission to a neonatal intensive care unit among children born to older fathers.

Other studies have identified associations with congenital heart disease, birth defects, childhood cancer and neurocognitive disorders, including schizophrenia, autism and obsessive compulsive disorder.

Older fathers and children’s health risks

The reason for this relationship remains unknown. Bachmann and her colleagues suspect that deteriorating sperm and reduced semen quality may be responsible, but this is only a hypothesis and needs substantially more research.

“Although it is well documented that children of older fathers are more likely to be diagnosed with schizophrenia - one in 141 infants with fathers under 25 versus one in 47 with fathers over 50 - the reason is not well understood,” explains Bachmann.

“Also, some studies have shown that the risk of autism starts to increase when the father is 30, plateaus after 40 and then increases again at 50.”

Reproductive health is clearly not an issue affecting women alone, yet women are still routinely expected to carry the full burden. Searching Google for “maternal age and pregnancy” produces roughly 65 million results. Replacing ‘maternal’ with ‘paternal’ brings up nearly four times less information.

Even the reproductive division of the US Centres for Disease Control and Infection (CDC) appears to concentrate exclusively on maternal and infant health, without referring to paternal influence in these areas. Indeed, the sole acknowledgement of a male counterpart is a decade-old report on improving male reproductive health, placed at the bottom of the CDC webpage.

“Perhaps this is rooted in the obvious role that women play in reproduction, leading us to perpetuate the idea that the topics of fertility, pregnancy and childbirth are women's issues, void of male involvement after their contribution of sperm,” the authors suggest.

Whatever the explanation, the limited awareness among men is worrying. Men over 45 are now far more likely to have children than they were four decades ago, but few doctors discuss fertility or the possible consequences of later fatherhood with their male patients.

“Men, too, need to recognise their clicking biological clock,” the authors write.

“Sperm banking for men who are delaying childbearing may need to be part of our societal responsibility commencing in the nearby future.”

If you intend to wait, or simply remain uncertain, it may be sensible to bank sperm while you are younger - or, at minimum, before turning 45. Otherwise, the reproductive clock will continue to tick away unnoticed.

The study was published in Maturitas.