Several months ago, my friend Anna called to complain about her boyfriend of eight months. Bombarded by media warnings about the female biological clock, he wanted to make sure that Anna was fit for childbearing before the relationship moved forward. He had taken her to a fertility clinic where a reproductive endocrinologist drew blood to check her ovarian reserve and injected radioactive iodine into her uterus to ensure that her fallopian tubes were clear.
Anna is 32. Her boyfriend is 52.
Anna’s boyfriend was right to be concerned. As women increasingly pursue careers and take advantage of fertility treatments to postpone childbirth into their 30s and 40s, they do place their offspring at risk for countless disorders and diseases. This occurs, however, not because of the woman’s age but because women in their 30s, like Anna, tend to couple off with older men. And when it comes to fathering healthy children, older men, it turns out, are just as much at the mercy of their biological clocks as women.
Older fathers made headlines several years ago when researchers at the Mount Sinai School of Medicine reported that a man over 40 is almost six times as likely as a man under 30 to father an autistic child. Since then, research has shown that a man’s chances of fathering offspring with schizophrenia double when he hits 40 and triple at age 50. The incidence of bipolarity, epilepsy, prostate cancer and breast cancer also increases in children born to men approaching 40.
Both dwarfism and Marfan syndrome (a disorder of the connective tissue) have been linked to older fathers, and according to research published in 1996 in the journal Nature Genetics, Apert syndrome (a disorder characterized by malformations of the skull, face, hands and feet) is a mutation caused exclusively by advanced paternal age.
A 2009 study at the University of Queensland, Australia, found a correlation between advanced paternal age and poorer performance by children on intelligence tests (the children of older mothers actually performed better). And when researchers at King’s College, London, bred mice from fathers of differing ages, the offspring of older fathers exhibited significant deficits in social and exploratory behavior.
Women are born with somewhere between one million and two million eggs, 75% of which are depleted by puberty. Eggs die daily