Pregnancy causes dramatic changes in the brain, study confirms

Pregnancy caused women to lose gray matter, and reshaped the brain’s “default mode network,” a set of brain regions that are most active when the mind is wandering. Pregnancy leads to striking changes in the brain, including alterations in gray matter and regions involved in self-perception, according to a new study.

The findings suggest that these neurological changes may promote bonding between mother and baby and could play a role in the identity shift that many women feel when they become new mothers, the researchers said. "These data provide key insights into the impact of becoming a mother on the human brain and point to pronounced changes in brain structure and function" during pregnancy, the authors wrote in the study, which was published Nov 22 in the journal Nature Communications. These changes "may confer adaptive advantages for a mother's gestational and maternal behaviour and the establishment of the new mother-child relationship," according to the study researchers, from Amsterdam University Medical Center.

The researchers again found that the women who became pregnant lost gray matter after giving birth. These gray matter losses aren't necessarily detrimental; rather, they may represent a "fine-tuning" of the brain that could be beneficial in caring for a new baby, they said. The researchers investigated what factors could be driving these brain changes, and their results point to a likely culprit: hormones.

Still, the researchers can't rule out the possibility that other factors not measured in the study — including exercise, nutrition and genetic markers — could be involved in these brain changes, and they called for further, larger studies to examine these factors.