Becoming a new parent can take some time to adjust, with many women experiencing cognitive struggles during pregnancy and after birth in what is commonly referred to as the 'baby brain'.  

But, a new study from the Carlos III Health Institute in Madrid found that men's brains can also be impacted by their new role as a parent.  

Researchers found on average, new fathers lost up to two per cent of their cortical volume following the birth of their first child.  

The shrinkage was mostly found in an area of the brain that is associated with warmth and parental acceptance, known as the 'default mode network'.  

The reason for the shrinkage is currently unclear, but researchers have suggested that the change helps fathers connect with their children easier.  

"These findings may suggest a unique role of the visual system in helping fathers to recognize their infants and respond accordingly, a hypothesis to be confirmed by future studies," the authors of the study wrote.  

"Understanding how the structural changes associated with fatherhood translate into parenting and child outcomes is a largely unexplored topic, providing exciting avenues for future research."  

The study was published in the Cerebral Cortex.