Pregnancy leads to changes in a mother's brain: study

A new study has revealed that pregnancy causes long-lasting alterations in brain structure by improving the mother’s ability to protect and interact with her newborn.

Researchers from Universitat Autonoma de Barcelona in Spain compared the structure of the brain of women before and after their first pregnancy.This research shows that pregnancy involves long-lasting changes — at least for two years postpartum — in the morphology of a woman’s brain.

Using magnetic resonance imaging, the brains of women who have undergone a first pregnancy, showed significant reductions in grey matter in regions associated with social cognition.The researchers believe that such changes correspond to an adaptive process of functional specialisation towards motherhood.

“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 specialised neural networks,” said co-lead author Elseline Hoekzema.

According to Erika Barba, the other co-lead author, “these changes concern brain areas associated with functions necessary to manage the challenges of motherhood.”

In



fact, researchers found that the areas with grey matter reductions overlapped with brain regions activated during a functional neuro-imaging session in which the mothers of the study watched images of their own babies.

In order to conduct the study, researchers compared magnetic resonance images of 25 first-time mothers before and after their pregnancy, of 19 male partners, and of a control group formed by 20 women who were not and had never been pregnant and 17 male partners.

They gathered information about the participants during five years and four months.The results indicated a symmetrical reduction in the volume of grey matter in the medial frontal and posterior cortex line, as well as in specific sections of, mainly, prefrontal and temporal cortex in pregnant women.

“The findings point to an adaptive process related to the benefits of better detecting the needs of the child, such as identifying the newborn’s emotional state. Moreover, they provide primary clues regarding the neural basis of motherhood, perinatal mental health and brain plasticity in general,” explained another researcher Oscar Vilarroya.

The study was published in journal of Nature Neuroscience.