Men should start having children before 35 to avoid harming the health of their partner and children, according to new research.
The study by Rutgers University is the latest in a growing field that suggests men, like women, may have a ticking biological clock.
Reviewing 40 years of research, the team found men over 45 are less fertile, and the women they impregnate have higher risks of pre-eclampsia (pregnancy-related hypertension), gestational diabetes and preterm birth.
Babies of older fathers were more likely to arrive prematurely or stillborn, to have poor overall health and a low birth weight, to suffer seizures, heart issues, and birth defects, and to develop childhood cancers or autism later in life.
It is unclear what drives this effects, but the researchers believe it could be to do with natural drops in testosterone levels over time – suggesting that earlier conception or banking sperm to use later could reduce health risks for mother and baby.
Researchers believe it could be to do with natural drops in testosterone levels over time – suggesting that earlier conception or banking sperm to use later could reduce health risks for mother and baby (file image)
‘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,’ said study author Gloria Bachmann, director of the Women’s Health Institute at Rutgers Robert Wood Johnson Medical School.
Women are deemed ‘geriatric’, by pregnancy standards, after 35. Studies suggest that by her late 30s, a woman has a higher risk of pregnancy complications, stillbirth, preterm birth, and more.
There is no defined standard for men who, culturally, have always been regarded as having an evergreen supply of sperm.
But as technology improves, scientists are able to take a closer look at what causes complications and health issues in embryos, fetuses, babies and mothers – and it seems paternal age could be a significant factor.
The issue is increasingly pertinent as the rate of first-time fathers over 45 steadily climbs – in the US that rate has soared 10 percent in 40 years – and sperm quality seems to be dwindling.
Beyond testosterone declines, Dr Bachmann believes passing time could be linked to sperm degradation and poorer semen quality, but more research is needed to firm up those links.
‘Just as people lose muscle strength, flexibility and endurance with age, in men, sperm also tend to lose “fitness” over the life cycle,’ Dr Bachmann said.
The study also found that older men struggled with fertility issues even if their partner was under 25.
‘While women tend to be more aware and educated than men about their reproductive health, most men do not consult with physicians unless they have a medical or fertility issue,’ Dr Bachmann said.