• Posted September 16, 2024

Pregnancy Changes the Brain, Study Finds

With implications for research around postpartum depression and other health issues, scientists have tracked the changes pregnancy brings to the female brain.

These changes weren't subtle: Big shifts in what's known as the brain's "white matter" versus "gray matter" were observed, according to a team from the University of California, Santa Barbara (UCSB).

“The maternal brain undergoes a choreographed change across gestation, and we are finally able to see it unfold,” said study co-author Emily Jacobs, an associate professor of psychological and brain sciences at the university.

The study is thought to be the first to track brain changes throughout a pregnancy, rather than looking at discrete 'snapshots' taken at various points in gestation.

The study focused on the brain of one woman undergoing her first pregnancy.

Researchers led by Laura Pritschet, a PhD student working in Jacob's lab, took scans of the woman's brain every few weeks -- starting before pregnancy, during gestation and then for two years after delivery.

The "neuroplasticity" observed in her brain was dramatic, Pritschet and colleagues report.

The biggest alteration came with the ratio of white matter and gray matter within the brain.

Cortical gray matter -- the kid found on the wrinkly outer surface of the brain -- decreased in volume as hormonal changes associated with pregnancy occurred, the researchers said.

That's not a particularly negative change, the researchers said, and might just reflect a "fine-tuning" of the brain as the body undergoes a major transformation. Similar changes in cortical gray matter occur during puberty, for example.

Meanwhile, white matter -- tissue located deeper in the brain and crucial to cross-brain communications -- appeared to increase during pregnancy.

But while the gray matter changes lingered long after a pregnancy, the white matter increase was transient, peaking in the second trimester but then reverting to earlier levels by the time of delivery.

The findings were published Sept. 16 in the journal Nature Neuroscience.

“Eighty-five percent of women experience pregnancy one or more times over their lifetime, and around 140 million women are pregnant every year,” Pritschet said in a UCSB news release.

She hopes to “dispel the dogma” that women are fragile during a pregnancy, showing instead the dynamism of the brain as it adapts to a new biochemistry.

Beyond pregnancy, the new research should “deepen our overall understanding of the human brain, including its aging process," Pritschet said.

Research into postpartum depression, which affects 1 in every 5 childbearing women, might also benefit from the new findings.

“There are now FDA-approved treatments for postpartum depression,” Pritschet explained, “but early detection remains elusive. The more we learn about the maternal brain, the better chance we’ll have to provide relief.”

More information

Find out more about postpartum depression at the Mayo Clinic.

SOURCE: University of California, Santa Barbara, news release, Sept. 16 2024