Expectant mothers undergo a variety of biological changes to their bodies during pregnancy, and researchers now have evidence that among those changes are alterations to brain structure, which appear to persist even two years after giving birth.
In a Nature Neuroscience paper published this week (December 19), a team of researchers at the Autonomous University of Barcelona compared MRI brain scans of 25 first-time mothers before and after they gave birth. The researchers found post-partem reductions of gray matter in regions of the brain involved with social cognition—the process of considering another person’s state of mind—and found that these same regions activated when the mother looked at photos of her child. And mothers that displayed the most significant brain changes tended to score higher on tests that measured their emotional attachment to their children.
The remodeling of gray matter could be a way for the brain to orient itself to the task of motherhood, the authors suggest. “These changes may reflect, at least in part, a mechanism of synaptic pruning, which also takes place in adolescence, where weak synapses are eliminated giving way to more efficient and specialized neural networks,” coauthor Elseline Hoekzema said in a press release.
An alternative explanation, University of Southern California neuroscientist Paul Thompson told The New York Times, is that these changes to the brain are simply the consequence of stress, loss of sleep, or changes to diet.