The benefits associated with being born in a later year outweigh the biological risks associated with being born to an older mother, researchers said.
The reason is that in industrialised countries educational opportunities are increasing, and people are getting healthier by the year. In other words, it pays off to be born later, they said.
Previous research suggests that the older women are when they give birth, the greater the health risks are for their children.
However, despite the risks associated with delaying childbearing, children may also benefit from mothers delaying childbearing to older ages, researchers from Max Planck Institute for Demographic Research (MPIDR) in Germany said.
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For example, a ten-year difference in maternal age is accompanied by a decade of changes to social and environmental conditions. Taking this perspective, the new study shows that when women delay childbearing to older ages their children are healthier, taller and more highly educated.
It shows that despite the risks associated with childbearing at older ages, which are attributable to ageing of the reproductive system, these risks are either counterbalanced, or outweighed, by the positive changes to the environment in the period during which the mother delayed her childbearing.
"Those twenty years make a huge difference," said Mikko Myrskyla from MPIDR. A child born in 1990, for example, had a much higher probability of going to a college or university than somebody born 20 years earlier.
Researchers used data from over 1.5 million Swedish men and women born between 1960 and 1991 to examine the relationship between maternal age at the time of birth, and height, physical fitness, grades in high school and educational attainment of the children.
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 their sibling born when the mother was in her early 20s.
"The benefits associated with being born in a later year outweigh the individual risk factors arising from being born to an older mother," said Myrskyla.