Maternal age is increasing all over the Western world, having now reached the average age of 31 for first-time mothers in Ireland, the highest in Europe as it stands.
But much as experts are warning about all the possible risks of leaving motherhood so late, becoming a mother in your 30s or even 40s is certainly not all bad news.
A recent study, published in the International Journal of Epidemiology, found that children born to older mums today are more likely to perform better in tests of cognitive ability compared to 40 years ago. The researchers at the London School of Economics and Political Science and the Max Planck Institute for Demographic Research looked at how the different characteristics of mums now giving birth to babies later in life mattered, noting that older mothers tend to, nowadays, be more “advantaged” – as in, they often have higher education, are at a better place in their careers, make more money and are much less likely to smoke during pregnancy.
As part of the research, the team examined data from three longitudinal studies conducted in the UK, one from 1958, another from 1970 and the latest dated from 2001. In each cohort, children’s cognitive ability was assessed when they were 10-11 years old.
Here are some of the most interesting finds the researchers discovered:
- In the 1958 and 1970 cohorts, children of mums aged 25–29 scored higher on intelligence tests than children born to older mothers.
- By 2001, however, this trend was reversed. Kids born to mums aged 30–34 and 35–39 had better outcomes than kids of mums aged 25–29.
- A similar pattern was observed for children of mums aged 40 and over – although the sample size was much smaller.
This is how the authors explains the results:
“The negative association [between mum’s age and children’s cognitive ability] in the earlier cohorts appears to be associated with the fact that the children born to older mothers in these cohorts were more likely to have been high parity births than their counterparts in the 2001 cohort.”
Meaning that back in the day, older mums were more likely to be giving birth to their third or fourth child if they were in their 30s or 40s, not baby #1. This matters when you know that many studies have shown that firstborn children typically perform better on cognitive ability tests, with a recent study showing eldest kids receive more “mental stimulation” from their parents.
“It’s essential to better understand how these children are doing given that, since the 1980s, there has been a significant increase in the average age of women having their first child in industrialised countries,” lead author Alice Goisis explains. “Cognitive ability is important in and of itself but also because it is a strong predictor of how children fare in later life – in terms of their educational attainment, their occupation and their health.”
