Older couples starting a family, or looking to expand theirs, can’t escape the ever-louder ticking of the biological clock.
Increased health risks for newborns have long been linked to the age of the mother at the time of conception, and now the age of the father may be a contributing factor, too.
“I wouldn’t be surprised,” said Bruce McGowan, 63, whose daughter was conceived naturally when he was 52 and his wife Collette was 35. The Fairfax, California, couple were married 10 years before starting a family.
“I have no regrets at all. I was ready and Collette was ready. In her mid-30s, she was getting anxious to have a baby,” McGowan said. “I was in good shape, no health problems. We’ve been lucky. No, I wouldn’t be worried as an older dad.”
But new research shows paternal genetic mutations, some that can cause serious health problems, are passed down at an increasingly higher rate from older fathers. The study by Icelandic researchers and published in the journal Nature concludes babies born to older fathers inherit more mutated genes, and thus are exposed to an increased risk of genetic disorders that include autism and schizophrenia.
Babies born to older fathers inherit more mutated genes, and thus are exposed to an increased risk of genetic disorders that include autism and schizophrenia.
Lead author Kari Stefansson, CEO of deCODE Genetics, a research firm in Reykjavic, is quick to point out that most mutations are harmless — even beneficial — in the evolutionary process.
“But this is not trivial,” Stefansson told LifeZette. “This has a significant impact on the health care system overall even if the concern for individual couples is relatively small.”
Stefansson and his team examined the entire genome systems of 78 Icelandic couples, ranging in age from their late teens to mid-40s, along with their offspring.
The rate of mutation for younger mothers did not vary significantly from older women, but the rate of mutation rose steadily with age in the male test participants. While the number of mutations passed to a child from either parent is a minuscule drop in the proverbial Olympic-sized gene pool, men on average pass on four times the amount of mutated genes than women.
“Seeing an association between (the) father’s age and (the) mutation rate is not surprising,” Stefansson said, “but with more than two extra mutations per year, the estimated effect of paternal mutations doubling every 16.5 years is striking.”
How concerned should couples be, particularly when education and career commitments mean many are starting families later in life?
One proud papa whose wife just gave birth to twins — 24 years after they bore their first daughter — said the health risks of conceiving never crossed his mind.
“When I had my first child, I was just 20 years old. I was more concerned about whether I could provide a good future for them then whether or not there would be health complications or birth defects,” Ubaldo Ramirez, 44, told LifeZette.
The property manager of Rancho Chiquita, a Malibu, California, wedding destination, Ramirez said the research findings make him feel blessed — not stressed.
“So many people are childless, so for me to have the wonderful fortune of having twins when I am in my 40s and so is my wife we feel very lucky. I was not aware of potential health complications for older fathers, but I would welcome a child into my life always. As practicing Catholics we do not use birth control, and so we rely on God’s will to give us the children as he sees fit.”
Yet the risks remain real, and something hopeful parents should consider when thinking about starting family — not just the age of the mother, but the age of the father as well.
“We don’t focus on the male component nearly as much as the age of the female,” said Dr. Anita Singh of Lifestart Fertility Center in Agoura Hills, California. “It is a much bigger factor, and there’s much more data on women’s fertility.
“When we do examine the male component,” Singh said, “it’s not really about the genetics as much as it is about low (sperm) count and motility.”
The study concurs that child health risks are much more of a concern with a mother’s increased age, but the results provide the first comprehensive data linking the age of the father to mutations passed down from one generation to the next.
“I am aware of the research, and there is some consideration to genetic markers in the father that have been identified as risk for certain abnormalities,” said Singh. “But we give much more consideration to the female. The age of the male, the impact is just so small compared to the female component. That’s just much more important.”
The lasting effect will advance further mutation studies of entire populations, with the father’s age at the point of conception now a variable to be considered.
“It is well known that demographic characteristics shape the evolution of the gene pool through the forces of genetic drift, gene flow and natural selection,” the study concludes. “With the results here, it is now clear that demographic transitions that affect the age at which males reproduce can also have a considerable effect on the rate of mutation.”