Do Women in Their 30s Have Smarter Babies?

A recent study finds that children born to women in their 30s might be smarter than babies born to moms in their 20s or 40s—and the reason why might surprise you.

Do Women in Their 30s Have Smarter Babies?

We've all heard that fertility starts to decline once a woman hits age 30—but some new information provides a great counterargument: Women might actually want to wait until their 30s to give birth.

Recent research conducted with data from The Millennium Cohort Study finds that children born to women in their 30s are healthier and smarter than children born to mothers in their 20s or 40s. The team of researchers analyzed the development of 18,000 British children to determine the link between the child's development and mother's age for the study, which was published in the journal of Biodemography and Social Biology.

According to results from the London School of Economics researchers, the children born to mothers in their 30s had higher cognitive scores than others.

Theories behind the findings

But these results might have more to do with sociological factors than just plain biology. For example, one theory is that women in their 40s don't seem to play with their children as much as younger women do. Women who give birth in their 30s also tend to be more educated and successful—after all, many of the women who delay motherhood do this so they can finish educating themselves and establish their careers a bit first.

"First-time mothers in their 30s are, for example, more likely to be educated, have higher incomes, are more likely to be in stable relationships, have healthier lifestyles, seek prenatal care earlier and have planned their pregnancies," researcher Alice Goisis told The Times.

Imperfect evidence

With that being said, data was analyzed from a large study—but there are just 53 children who were born to mothers in 40s included, which likely means more research is needed before a conclusion can be reached. Despite the fact that so few of the children analyzed were born to older mothers, mothers in the US are having babies later and later. The average age of first-time mothers was 21.4 in 1970 but had risen to 26 by 2013, according to the Centers for Disease Control and Prevention.

As with all other studies, you should ultimately make the decision that works best for your life—if delaying motherhood until your 40s or having children in your 20s is the right choice for you, no study should deter you. These are simply findings and while they're interesting, they're just one piece of a complicated puzzle.

Related: Putting Off Motherhood Could Be Good for You