We all know that pregnancy and parenthood brings about profound changes. Yet while we’re aware of some of the more visible changes — the bump, the swelling, the look of chronic exhaustion — there’s a lot less focus on how the brain changes through gestation and parenthood.
And even when these changes are acknowledged, they’re usually dismissed as ‘mum brain’ or ‘pregnancy brain’ — slip-ups and oversights that tend to come with associations of scattiness.
But it turns out that the brain changes in very practical and beneficial ways during the early days of motherhood, triggering long-lasting changes to our cognitive abilities.
BBC Science journalist and author of The Motherhood Complex, Melissa Hogenboom became irritated by the term ‘mum brain’ after the birth of her two children (now five and three).
“I was like, ‘Wait a minute. That can’t be true’. When I came back to work, I felt more ambitious and more motivated. And I was juggling so much and [was] doing more than ever before,” she says. “Then when I looked at the literature, there’s some really interesting neuroscience that explains that during pregnancy your brain is optimised in a way that is beneficial to you.”
Pregnancy and parenthood cranks neurological development up a gear, she explains. During these hugely demanding periods of life there is a reduction in grey matter. That might sound scary — we usually associate a decline in any area of our brain as something to be concerned about — but this process is known as “synaptic pruning”, a brain phenomenon that eliminates certain connections between brain cells to encourage the facilitation of new connections. It occurs during pregnancy and parenthood to increase levels of empathy and theory of mind — aka the capacity to understand and perceive how others see things.
In studies in the US, scientists have collated evidence that shows that female brains change most quickly during pregnancy/ the postpartum period.
Hogenboom compares it to trimming back overgrowth in a garden to allow other flowers to bloom.
“It’s as if you’re getting rid of the weeds… and making other stuff more prominent… So the connections of those sections are stronger, and that is long-lasting as well.”
Some scientists argue that in the postpartum period our brains have increased plasticity — which is essentially the ability to reorganise.
A 2016 study published in the journal Nature Neuroscience scanned women’s brains and found those whose brains had changed the most typically had a stronger emotional bond with their children.
Pregnant people often feel undervalued and overlooked so it’s refreshing to hear your brain goes into hyperdrive during this period. Meanwhile, in the States, there have even been calls to ‘reframe mom brain’ as a positive or a ‘superpower’.
When she began researching her book, Hogenboom discovered other ways the brain is changed during pregnancy. She becomes animated when discussing microchimerism — the process where cells move between the pregnant person and the fetus.
“Fetal DNA transcends the blood-brain barrier. So you have these little snippets of your baby’s DNA inside you forever,” she explains. “And it’s been found in breast milk, it’s been found in C-section scars and it’s been found in the brain… [Scientists] analysed the brains of women who died in their 80s and found male fetal DNA… so it shows that you’re literally consumed by snippets of your baby’s DNA for life.”
However, Hogenboom stresses that while these changes occur with biological mothers, the lived experience of caring for a child can also result in comparable hormonal and neurological shifts in non-biological, adoptive or same-sex parents.
“I’m always really careful when I talk about this kind of research because some people may interpret it as something called biological essentialism, to show that we are primed for caregiving. That’s not necessarily true,” she says.
“Yes, the hormones give us a head start and result in these beneficial brain changes. But then the experience factor takes over.”
She cites a study in the US that shows non-biological parents experience beneficial brain changes in terms of things like an oxytocin boost.
“You’re primed by doing as well. Your brain changes with everything you do.”
As she discusses the neurological changes and the ongoing way having children can mentally test you, a lot of it hits home.
Like when we talk about the trauma of hearing your two small children crying in unison for the first time. “Your brain literally is going into fight-or-flight mode because you want to fix it, because you’re empathetic,” she explains. “So your brain goes into empathetic over-arousal… and because you can’t control everyone’s emotions it’s intensely stressful.”
Personally, I find it hugely reassuring to know that there is some reason or logic to feeling paralysed and unable to think in those situations. For some reason it feels like less of a personal failure when I understand what is going on inside my head.
Given all these profound neurological changes that are occurring in the brain and body, it makes sense why so many parents feel a stark shift in their identity after having children.
“I thought there must be a scientific reason for why this is so overwhelming and why the identity shift is so stark, and it turns out there is a lot of science to do with it,” she says.
“Our brain is changing and we feel different afterwards. And yet, in some sense, we’re expected to just go back… [when] our whole sense of self has completely changed.”
This is compounded by a societal expectation for women to return (the dreaded ‘bounce back’) to their professional and personal lives as if nothing happened — when most feel there has been an intense and irreversible change that they are still processing.
That expectation can sometimes be paradoxically coupled with being viewed as primarily a mother in huge sections of your life.
In hospitals and creches, first names seem to evaporate and you become Sadie / Jack / Lucy’s mum.
“Your sense of who you are gets overridden by how other people see you. So you might see yourself as a competent journalist or an ambitious career woman but as soon as you become a mother, there’s all these other expectations and judgements put upon you… your identity kind of is erased because your child is suddenly the most important thing and there’s good practical reasons for that. But psychologically, that can feel quite uncomfortable, especially when no one kind of explains that.”
Hogenboom believes the best way to deal with these feelings of identity loss is to acknowledge, validate and then find ways to practically solve them.
She came to this realisation after the birth of her second child, which she found challenging. When she told a fellow mother at a baby meet-up group that she was finding things ‘awful’ the woman looked shocked.
“For the first six months, my toddler was running away while I was holding the baby or she was biting the baby because she wanted attention and wasn’t getting it. Or I was putting her to bed while my baby was screaming. However much you love your children, that is not fun,” she says.
“People don’t talk about how hard it is and just how difficult the day-to-day is… that constant tug on your attention. How you’re always feeling guilty, because you’re never quite doing enough. You’re trying to reach these perfect ideals that are actually impossible,” she says.
“I think when you validate and understand that you can take steps to tackle what you are going through… it can empower you… and can then really help you be a better parent.”
