The impact of having older parents on the child isn't well understood, but it's clear there are potentially serious issues.
What science tells us about the aging parental body should alarm us more than it does. Age diminishes a woman’s fertility; every woman knows that, although several surveys have shown that women—and men—consistently underestimate how sharp the drop-off can be for women after age 35. The effects of maternal age on children aren’t as well-understood. As that age creeps upward, so do the chances that children will carry a chromosomal abnormality, such as a trisomy.
These effects are not limited to having an older mother.
The Nature study ended by saying that the greater number of older dads could help to explain the 78 percent rise in autism cases over the past decade. Researchers have suspected links between autism and parental age for years. One much-cited study from 2006 argued that the risk of bearing an autistic child jumps from six in 10,000 before a man reaches 30 to 32 in 10,000 when he’s 40—a more than fivefold increase. When he reaches 50, it goes up to 52 in 10,000. It should be noted that there are many skeptics when it comes to explaining the increase of autism; one school of thought holds that it’s the result of more doctors making diagnoses, better equipment and information for the doctors to make them with, and a vocal parent lobby that encourages them. But it increasingly looks as if autism cases have risen more than overdiagnosis can account for and that parental age, particularly paternal age, has something to do with that fact.
Having a child later in life can bring more than just health issues.
But the experience of being an older parent also has its emotional disadvantages. For one thing, as soon as we procrastinators manage to have kids, we also become members of the “sandwich generation.” That is, we’re caught between our toddlers tugging on one hand and our parents talking on the phone in the other, giving us the latest updates on their ailments. Grandparents well into their senescence provide less of the support younger grandparents offer—the babysitting, the spoiling, the special bonds between children and their elders through which family traditions are passed.
They found that when mothers delayed childbearing to older ages, even as old as 40 or older, they had children who were taller, had better grades in high school, and were more likely to go to university. For example, comparing two siblings born to the same mother decades apart, on average the child born when the mother was in her early 40s spends more than a year longer in the educational system than his or her sibling born when the mother was in her early 20s.
While there are risks to the children, the social benefits may outweigh it.
"The benefits associated with being born in a later year outweigh the individual risk factors arising from being born to an older mother. We need to develop a different perspective on advanced maternal age. Expectant parents are typically well aware of the risks associated with late pregnancy, but they are less aware of the positive effects" said Myrskylä.