“Remind me never to go into business with a pregnant woman again!” said my then childless business partner. I was so hurt and upset, I had to take myself off for a big cry. We’d just come out of a meeting with the builders overseeing the development of our shoppers’ crèche, Kinderpark, in Wood Green Shopping Centre. Try as I might, I just couldn’t get my head around the figures they were presenting. It all felt like gobbledygook, as though my brain was wading through fog.
The BBC series Child explains that the physical strain a woman is under in the final trimester is equivalent to that of an Olympic athlete at peak training. The brain, in its wisdom, starts prioritising only what’s essential to keep the body going, shelving anything it deems unnecessary, like complex building quotes!
The brilliant news is that after birth, the brain begins building new synapses, and mums often become sharper than ever - organised, efficient, brilliant multitaskers, and creative problem solvers. As an employer now, there’s no one I’d rather hire than a mum of a two year old!
Becoming a parent is one of the most transformative times in a person’s life. Not only does having a baby dramatically change how you live your life, it changes the way you think, behave, and, as science is beginning to discover, it physically changes the structure of your brain.
Why does this matter? Understanding how parenthood alters our brains could be key to self-compassion during this transformative and tumultuous time.
You may have heard the phrase ‘mummy brain’ or ‘baby brain’ thrown around to describe the forgetfulness and brain fog that new mothers experience in pregnancy and early motherhood. Although it’s usually a throwaway comment, there are many solid biological reasons why ‘baby brain’ happens, which are infinitely more complex than the dismissive idea that it just makes a new mother more likely to forget her keys. It doesn’t just affect mothers either; there is increasing evidence that men’s brains also go through significant changes when they become fathers.
In this study, published in Nature Neuroscience, researchers found there was a reduction in grey matter in certain areas of women's brains during pregnancy lasting for two years postpartum. Although this sounds like a negative, it may mean that new mothers' brains are more efficiently wired in key areas, such as responding to their infant's needs or detecting threatening people in their environments.
It could also play an important role in bonding. In one task, mothers were shown pictures of their own babies and other babies whilst their brain activity was monitored. The parts of the brain which lit up when they saw pictures of their own babies closely matched the areas where grey matter had been reduced or "fine-tuned" during pregnancy. The same areas did not light up when pictures of other babies were viewed.
“This presents a compelling idea that ‘baby brain’ is an important adaptive phenomenon that might help women prepare for raising their children by allowing their brains to adapt to their new role as mothers,” says Sasha Davies, first author of the Medical Journal of Australia study.
Scientists have discovered that the brain is at its most plastic and malleable during the transition into motherhood. This plasticity is driven by hormonal changes and the new demands of motherhood, resulting in changes in brain structure and function that support the mother's new role.
The only other time in life when a human’s brain undergoes remodelling as significant as this is during adolescence. This understanding has led to the increasing popularisation of the word ‘matresence’ to describe the significant physical, psychological, and emotional transition a woman undergoes when becoming a mother.
During pregnancy and postpartum, scientists have found significant growth in the amygdala, an almond-shaped set of neurons in the lower centre of the brain which helps to process memory and drives primal emotional reactions like fear and aggression. Growth in this area of the brain, caused by an increase in oxytocin (the bonding hormone), helps mothers to deepen their connection with their baby and be hypersensitive to their needs.
Whilst the brain undergoes some structural changes during matresence, we can’t underestimate the impact of hormones and sleep deprivation on the brain’s ability to function effectively.
Hormonal changes, particularly those involving estrogen, progesterone, and prolactin, can affect brain structure, function, and cognitive processes.
Estrogen and progesterone, which influence brain regions associated with mood, memory and social behaviour, rise gradually during pregnancy, peaking just before birth and declining sharply after giving birth. The sharp decline in both of these hormones after giving birth can contribute to irritability, low mood, anxiety and in some cases, postpartum depression.
The same can be said for the hormone prolactin, responsible for milk production, which can lead to feelings of sadness, anxiety, or irritability as levels drop postpartum, particularly during weaning.
In 2020, a groundbreaking study by a group of scientists in Madrid looked at the brains of men before their partners became pregnant and after the baby was born. They discovered that having a baby changes a father’s brain anatomy, too.
First-time fathers showed a significant reduction in the volume and thickness of grey matter in specific areas of the brain associated with empathy, attention and visual processing. The higher the volume reduction, the stronger the father’s brain responds to pictures of his baby. Although this might sound like a negative effect, researchers theorise that, similarly to changes seen in new mothers, this means that the brain is becoming more streamlined or fine-tuned to take care of an infant.
Lucy Jones, author of the book Matresence, said:
“This is built on previous studies, which found that the amount of time a father spends with their baby, and how affectionate he is, is associated with the reduction of testosterone, and increases in oxytocin and activity in the brain’s reward systems. In other words: the more a father cuddles, holds, gazes at, speaks to, sings to and plays with his infant, the more rewarding he finds it.
Neurobiology suggests people of all genders experience parenting in much the same way: it can just take longer for fathers, as well as non-biological mothers and adoptive parents. They also develop the hormones associated with nurturing – oxytocin, prolactin, and vasopressin.”
Fathers also experience a decrease in testosterone levels when becoming a parent which is thought to shift focus away from a mating instinct and towards a nurturing instinct. They are therefore more sensitive to their children's needs and more likely to respond to their cries.
Although the immediate impacts of pregnancy and early parenthood on your brain might leave you feeling scatty and foggy, the good news is that it is transitional (and often compounded by sleep deprivation in the early years). Long-term there are may be many important benefits to your brain such as;
Memory Improvement:
The streamlining that your brain goes through when becoming a parent means that it is primed for learning new things. Some studies suggest that mothers may even experience better memory retention overall after the first two years postpartum.
Resilience to Age-Related Decline:
Evidence suggests that motherhood can protect against age-related cognitive decline and even make the brain more resilient in later life. Studies indicate that the structural and functional changes in the brain experienced when women become mothers, potentially lead to a "younger-looking" brain and improved cognitive performance, particularly in verbal memory, in middle-aged and older women.
Increased empathy
As a parent you are constantly trying to understand and respond to your child's needs. This strengthens the brain's capacity for empathy and theory of mind (understanding others' perspectives).
Did you experience brain changes when you became a parent? How did it affect you?
