What happens in a woman’s body when she becomes a mother?

“There are so many hormonal changes that take place which influence mood, the thyroid and the brain, which can take months to years to go away,” she says. “Breasts, whether you’re breastfeeding or not, tend to get bigger and remain so until you stop. The uterus shrinks in the first six weeks after birth, and it’s normal to get period-like cramping, discharge and some blood.”

Constipation is also common, and bladder control issues can arise, which can potentially be minimised if the pelvic floor is looked after by a woman’s physio. Beauty – which covers hair loss, skin conditions such as eczema, pigmentation, all sorts of rashes, stretch marks and even gum disease – also takes a beating.

Yet, as Leahy found, understanding what underpins our socio-cultural ideas about motherhood can tell us a lot about the psychological state of women who have just become parents, as well as those who have been mothers for a long time.

“There are so many shifts that happen in and to the mother,” says professor of psychiatry at Alfred Health, Jayashri Kulkarni. “For one, this is the only time in your life when you grow a whole other organ, the placenta, which has its own brain and which is part of the mother-child feedback loop of communication.”

Then there are the necessary immunology changes that help keep the foetus – essentially a foreign body whose DNA is half the father’s – alive. “The maternal immune system dampens the signals responsible for getting rid of a foreign body and accepts it,” she says.

“This is huge, and there can be lasting reminders of the immunological and brain chemistry in the maternal system”.

These significant neurological and brain changes have since been documented, with a 2016 study published in Nature Neuroscience finding that the grey matter (which plays a role in tasks such as hearing, seeing, processing memories and decision-making) in the brains of women who have recently given birth seemed to be reduced in certain areas, and that those changes stuck around for up to two years after birth.

However, these results are now being challenged, with researchers from the Turner Institute for Brain and Mental Health finding that the “baby brain” tag may actually be the result of sleep deprivation and the higher cognitive load that comes with having a baby, rather than acute changes in the brain.

“That grey matter paper is high profile and has been very influential in this area, but subsequent studies have not found such clear results,” says Associate Professor Sharna Jamadar. “The paper is probably based on a snapshot of women taken at a particular time in the parenting trajectory”.

Jamadar says the idea of the baby brain is so pervasive that it underpins mothers’ own judgments about their forgetfulness and cognitive abilities during the early years of parenting.

For the Turner Institute study, she and co-author Dr Winnie Orchard tested 43 mothers and 43 non-mothers on their verbal memory, working memory, processing speed and theory of mind (the ability to understand the reasons behind others’ behaviour), and found largely no differences.

Loading

“We think that when you’re a mother, you tend to be more focused on these periods of forgetfulness, not only because we have a social narrative about the baby brain, but also because memory errors in the postpartum period also carry heavier consequences, such as a sleepless night or, in extreme cases, harm to the baby.”

In fact, another study conducted by Orchard found that elderly mothers (aged in their 70s) actually had better brain function than elderly non-mothers.

“Becoming a mother is a huge thing – it adds so much more complexity to your life,” Jamadar says. “The early grey matter decline is probably the result of all this new stuff you have to learn and all that is going on, but across a lifespan, it does add up to cognitive protection.”

Make the most of your health, relationships, fitness and nutrition with our Live Well newsletter. Get it in your inbox every Monday.