Pregnancy May Result in Long-Term Changes to a Woman's Brain

New study examines how pregnancy can alter a woman's brain as well as her body.

— -- Pregnancy may result in long-lasting changes in a woman's brain, according to a study of a small group of subjects published on Monday by the journal Nature Neuroscience.

Researchers examined the brains of 25 first-time mothers before and after their pregnancy and found that after a pregnancy there was a decrease in gray matter in regions of the brain that are associated with functions such as integrating sensory information and abstract thinking. The researchers followed up with 11 of the women two years after they gave birth and still observed those changes.

The changes to new mothers' brains were so distinct that the scientists were able to correctly determine about 85 percent of the time whether a woman recently gave birth, just by looking at her brain scan.

"They actually found changes in parts of the structure and size of the brain. The theory here is that those changes occurred to help streamline the moms' brains to prepare for more nurturing, vigilance and teaching," said Dr. Jen Ashton, ABC News' chief women's health correspondent. "We all know women who say, 'You know, I wasn't that maternal until I had my own child, and then something clicked,' or we become multitaskers."

"The current findings indicate that human pregnancy is associated with substantial long-lasting alterations in brain structure, which may serve an adaptive purpose for pending motherhood," reads the study, authored by Elseline Hoekzema of Leiden University and a team of researchers at the Autonomous University of Barcelona. "These data provide, to our knowledge, the first insights into the profound impact of pregnancy on the gray matter architecture of the human brain."

The researchers also examined first-time fathers and did not observe these brain changes.

“Interestingly, they studied male brains, and no difference. No difference in the male brain. Not even a little bit," Ashton said. "I’d like to see the study done in adoptive moms too."

The brain changes that the scientists observed in the mothers were not measured in terms of cognitive performance or intellectual sharpness, so it is impossible to directly link the alterations to real-world outcomes. The authors of the study speculated that the gray matter changes may facilitate a mother's attachment to her baby.