A new study revealed that the brain of women during their first pregnancy undergoes structural changes in certain regions that could usually last for at least two years after the pregnancy.
The study, published in the journal Nature Neuroscience, showed that first time expecting mothers have a significant reduction in grey matter in some regions of their brain associated with social cognition and self-focused processing.
"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", explained co-lead author Elseline Hoekzema, currently working at Leiden University and a researcher at Universitat Autonoma De Barcelona during the time of the study, in a press release.
For the study, the researchers recruited 25 first-time mothers and 19 male partners. The researchers asked the participants to undergo brain scans. The magnetic resonance images of the participants were then compared to a control group consisting of 20 women who were not and never been pregnant and 17 male partners.
The researchers observed a symmetrical reduction in the volume of grey matter in the medial frontal and posterior cortex line in pregnant women. Synaptic pruning was also observed in specific sections of prefrontal and temporal cortex of pregnant women.
When the mothers involved in the study watched images of their babies during a functional neuroimaging session, the researchers observed that the areas in the brain activated by the images overlaps with the regions that experience significant reduction in grey matter volume.
Despite the reduction of grey matter volume, the researchers found no changes in the memory or cognitive functions during pregnancy. Due to this, the researchers believe that the grey matter pruning experienced during pregnancy is some sort of an adaptive process of the brain in preparation for motherhood.