The long-debated phenomenon of ‘baby brain’ may actually be a significant structural overhaul, not just a lapse in memory, a study finds.
According to a landmark study published in Nature Communications, a mother’s brain undergoes a profound ‘rewiring’ process during pregnancy to prepare for the demands of parenthood.
Researchers with the Be Mother project, the largest study of its kind, monitored 127 women through a series of MRI scans and hormone tests before, during, and after pregnancy, with the results revealing a striking physical transformation.
Expectant mothers lost an average of nearly five per cent of their grey matter, the tissue responsible for processing emotions, information, and empathy.
This loss isn’t a sign of decline as Lead researcher Professor Susana Carmona of the Gregorio Marañón Health Research Institute likened it to pruning a tree. ‘Some branches are cut to make it grow more efficiently,’ she explained.
While the grey matter partially returned within six months postpartum, the initial shift suggests the brain is ‘priming’ itself for maternal instincts.
For years, ‘baby brain’ has been synonymous with ‘brain fog’ or intellectual lapses. However, this research suggests the brain isn’t becoming ‘dumber’, it’s becoming specialised.
The study found that a mother’s brain undergoes a profound ‘rewiring’ process during pregnancy to prepare for the demands of parenthood.(stock photo of a mother with her child)
Expectant mothers lost an average of nearly 5% of their grey matter, the tissue responsible for processing emotions, information, and empathy
Speaking to the BBC, Tania Esparza, a participant in the study said: ‘I’m tired of pregnant women being infantilised.
She added: ‘Rather than becoming dumber, we are becoming more specialised for the job.’
Ana Mudrinic, a new mum, told the BBC that at times during her pregnancy, she felt forgetful. She said: ‘I wanted to send an email to my boss and in that moment, I simply couldn’t remember her name.’
The team, co-led by Professor Oscar Vilarroya, compared the pregnant participants against a control group of 52 women who had never been pregnant.
While the control group’s brain structures remained steady, the pregnant women showed clear, consistent neural remodelling driven by hormonal shifts and changes to blood vessels and nerve networks.
The study didn’t directly examine pregnancy-related memory changes; however, a small 2016 study of 25 women by Professor Carmona’s team found no notable impact.
