First-time Fathers May Experience Brain Shrinkage, Scientists Reveal

parenthood fatherhood motherhood parenting Brain Shrinkage First-Time Dads first-time fathers

By Joel Brussels , Parent Herald Sep 12, 09:02 pm

Photo: (Photo : MARTIN BUREAU/AFP via Getty Images)

Becoming a new parent is an adjustment not only for women who gave birth to the baby but also the men. A dozen or so studies conducted previously have shown that motherhood can change the structure of a mom's brain. However, fatherhood is comparatively overlooked and its effect on dads.

That has now changed with new international research identifying neurological changes amongst first-time dads. The research, using data from the "Adolescent Brain and Cognitive Development" study suggests that the neural substrates of parenthood are not exclusive to moms, as dads can also be impacted by their new role as a parent, albeit in a less pronounced way.

The researchers found that new dads lost a percentage or two of cortical volume, on average, following the birth of their first child. The shrinkage found in the father's brains was mainly confined to an area known as the 'default mode network.' That part of the brain is associated with warmth and parental acceptance.

Brains of new dads that shrank being refined

A loss in cortical volume might sound like a bad thing at first, but it can indicate a refinement of the person's brain that makes connecting with a child more efficient and powerful. Similar cortical losses found in moms, for example, are associated with greater neural responses to a kid and stronger attachment between parent and child.

Previous studies have found subtle neurological changes in a new dad's brain following his child's birth. However, little evidence collected regarding this matter has proved conflicting and mixed.

Some studies showed increases in the gray matter following the birth of a baby, while others showed losses. Different regions of the person's brain have also been implicated, and few methods have differentiated between first-time fathers, dads of multiple children, and childless men.

Dads from Spain and the United States participated in the international study

The new study is more rigorous than most as the research is based on magnetic resonance imaging (MRI) data from 40 heterosexual first-time dads, half of whom were based in the United States and half in Spain.

The expectant dads in Spain participated in brain scans before their partners' pregnancies and then again a few months after the birth of their child. On the other hand, the expectant dads in the U.S. participated during the mid-to-late stages of their partners' pregnancies and then again seven to eight months postpartum.

The new study also included a control group of 17 men without kids based in Spain. The two laboratories in charge of the research gathered all their data and compared the thickness, volume, and structural properties of the male brain in each of the three groups.

Compared to similar studies on new moms, first-time dads in the current research did not show changes in their limbic subcortical network, according to Science Alert. This finding makes sense as this part of the brain is associated with pregnancy hormones.

Dads not carrying their babies as they develop and grow does not mean their brains are not impacted by parenthood. First-time dads showed signs of brain plasticity in their cortical gray matter, which is involved largely in social understanding. The study's authors also found pronounced reductions in the visual system's volume.