Why has it taken scientists this long to confirm 'mum brain' isn't just a pop culture term?

Liz Chrastil, a neuroscientist with the University of California, Irvine, holds her newborn son in May 2020. Liz Chrastil via AP

In the polarising conversations on social media about women’s bodies, it can be easy to forget one simple, extraordinary fact. Women’s bodies are capable of making new, tiny human beings. Little people that grow into big people with their own bodies, brains, ideas and personalities. It still astounds me because on an entirely personal note, nearly 15 years into my own motherhood journey, when I look at my children, I think, wow, they came from me.

I’ve been in a state of hyper-astonishment since reading about the publication of a new study demonstrating brain neuroplasticity during pregnancy. Pregnancy doesn’t just reshape lives, and create tiny people, it literally rewires women’s brains.

A study by neuroscientists at the University of California conducted 26 MRI scans before, during and after pregnancy of one woman, a neuroscientist herself, to see how the brain changes. Previous studies have looked at the before and after, but this time we get to see what happens during the pregnancy.

It showed a reduction in the volume of grey matter, which persists after the pregnancy, and an increase in white matter, which subsides after the pregnancy ends. The purpose exactly of these changes is still a matter of uncertainty. Grey matter is linked to cognitive function like thought and memory, and some speculation suggests it is a process of refinement.

Other periods of extreme brain neuroplasticity include, for example, puberty. The increase in white matter is thought to be about increasing communication between brain regions.

Or to put it in common parlance, "mum-brain" is a thing. But perhaps not in the trivial and sometimes demeaning way it is used colloquially – including by women.

"Mum-brain" is a pop culture term, referring to absent mindedness or feeling "brain fog", which might be as much to do with sleep deprivation and being on call 24/7 for a baby. But what this study shows is that actually might be the brain evolving, preparing a pregnant woman for motherhood. So the dynamic process of neuroplasticity termed "mum-brain" might not be a sign of cognitive loss but of improvement and focusing on what matters most in the core human function of giving birth to and nurturing a child.

Recognising the neurological changes that happen during pregnancy and what people experience is a fundamental step towards understanding the full scope of womanhood. PA Wire

In part, I am astonished at how the change to the female pregnant brain is being studied only now. There are a number of studies that show women are overlooked or undermined in data. Such oversight seems to be not just a glaring gap in scientific understanding, but a reflection of society’s ideas about women and pregnancy in general. Which is why it doesn’t surprise me that the study was led by women, and the subject was herself a neuroscientist who proposed the idea.

Societal views about pregnancy are a paradox. Some views might hold that pregnant women are fragile, vulnerable and don’t know their own minds. At the same time, it’s so completely ordinary that women should just carry on as normal both in the workplace and at home without complaint.

Biologically, pregnancy is extraordinary, but culturally the idea of pregnancy swings on a pendulum – between being minimised in some parts of society or being put on a pedestal.

Investigations of this profoundly female experience will hopefully be a groundbreaker for listening to women’s experiences

When it’s minimised, women tend to suffer through the attitudes of others and being treated as if they need to suck it up because millions have gone through pregnancy before them and it's normal to suffer.

Conversely, when pregnancy is put on a pedestal, it can appear that women can’t complain because motherhood is the pinnacle of the human process. And so they ought to stop complaining that it's physically exhausting, which is why perhaps a pregnant woman is too tired to clean the house.

That’s why studies like this are so important. They give us scientific data about pregnancy and women, and objective information to substantiate what women actually say about themselves. It's important to compare the stereotypes we hold about pregnancy to actual scientific proof.

The fact that some parts of science are have only now caught up to this reality suggests that society, too, has some catching up to do.

In my view, it’s lazy to think of pregnancy as nothing more than a purely physical transformation limited to the period of reproduction. This research shows that it’s much deeper, probably altering a woman’s sense of self, cognitive powers as well as her identity in the public space.

Recognising the neurological changes that happen during pregnancy and what people experience is a fundamental step towards understanding the full scope of womanhood.

Even as global fertility rates have dramatically declined and globally women are having fewer children, pregnancy is an existential, life-altering process.

If there were other physical process that were this widespread and fundamental I can’t imagine that we wouldn’t be racing to explore every single aspect of its impact.

Investigations of this profoundly female experience will hopefully be a groundbreaker for listening to women’s experiences and taking them more seriously. That societies generally tend to not give women’s voices about their own physical experiences more credence is still astonishing to me.