In a December article for The New Republic, “The Grayest Generation: How Older Parenthood Will Upend American Society,” the magazine’s science editor Judith Shulevitz points out how the growing trend toward later parenthood since 1970 coincides with a rise in neurocognitive and developmental disorders among children.
Drawing on research published in Nature, Shulevitz writes that, while the associations between parental age and birth defects were largely speculative until this year, “when researchers in Iceland, using radically more powerful ways of looking at genomes, established that men pass on more de novo — that is, noninherited and spontaneously occurring — genetic mutations to their children as they get older. … [T]hey concluded that the number of genetic mutations that can be acquired from a father increases by two every year of his life, and doubles every 16, so that a 36-year-old man is twice as likely as a 20-year-old to bequeathde novo mutations to his children.”
By proving that it’s not simply the mother’s age and health that affects the fetus, Shulevitz says the dynamic surrounding discussions of fertility will change. “No longer need women feel solely guilty,” she tells Fresh Air’s Terry Gross. “They can point to their husbands — and perhaps that’s not really a nice way of putting it — but it means that the problem is shared by both sexes.” Read full article.