Pregnant women have a long list of rules to follow to protect the health of their child. But there's now startling evidence to suggest the lifestyle choices of fathers should be called into question too.
Michael Douglas is said to have seduced Catherine Zeta-Jones, 25 years his junior, with the unforgivable line “I’d like to father your children”. When she acquiesced, Zeta-Jones paid a price she was probably unaware of – a higher risk of health problems for those children.
It turns out that at least some of the risk of problems ranging from Down syndrome, schizophrenia and autism to obesity and poor social skills can all be linked back to the father’s age and environment around the time of conception. And yet most couples have never heard of these findings.
Similarly, a current public health campaign in Britain warns fathers not to smoke around their pregnant partners, but it doesn’t mention anything about the risks of men smoking themselves at the time they are trying to conceive.
“It’s not as though the scientific community has kept quiet about this, but the popular media has not picked up on it,” says Mary Cannon, a psychiatrist at the Royal College of Surgeons in Ireland. “My hunch is that the area of reproducing, especially fertility and the health of offspring, is somehow seen as women’s business.”
Cynthia Daniels at Rutgers University, in New Jersey, USA, agrees. “It’s a function of gender bias that we haven’t focussed more attention on the role of men in healthy pregnancy outcomes,” she says. “We continue to see reproduction as the exclusive responsibility of women – and we’re reluctant to recognise men’s responsibilities as well.”
When it comes to fertility, most women know that it’s best to avoid alcohol and too much caffeine, to maintain a healthy weight and to have children earlier rather than later. But what kind of influence does the would-be father have on the success, or otherwise, of conception – and how exactly are these environmental factors inherited?
For men, it seems that caffeine might actually help. One Brazilian study found that the sperm of men who drank one or more cups of coffee a day were much better swimmers than the sperm of men who avoided caffeine.
But other drugs are bad news. A U.S. study found that marijuana smokers have fewer sperm, and these sperm have swimming problems: they move too fast too early, potentially leading to burn-out before they get near an egg. Excess body fat can also cause problems for wannabe dads as it lowers testosterone levels, which in turn reduces a man’s sperm count. Meanwhile, smoking and drinking can harm a man’s ability to conceive by damaging the DNA of his sperm.
Of course, smokers and drinkers do father children. But that doesn’t mean that a few good sperm escaped the toxic chemicals in pristine condition.
The cause of some 60% of birth defects isn’t known, but sperm abnormalities caused by a father’s heavy drinking may be one important factor and should be urgently investigated, says political scientist Daniels. “The research that has been done shows that men’s excessive alcohol use can cause increased rates of low birth-weight babies, as well as increased rates of sperm abnormalities.”
But researchers who have found associations between paternal alcohol use and harm have had a difficult time getting funding for further work, she says. “As a result, public attention is focussed exclusively on women’s use of alcohol – even though women who consume alcohol during their pregnancies are highly likely to be partnered with men who abuse alcohol.”
Article from cosmosmagazine.com