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MRI scans of a pregnant woman before, during and after her pregnancy. “/>Neuroscientists at the University of California, Santa Barbara obtained MRI scans of a pregnant woman before, during and after her pregnancy. © Jeff Liang/The Washington Post
How does the brain change during pregnancy? A scientist had herself examined before, during and after her pregnancy and shows results.
Scientists have captured the cognitive development of a woman becoming a mother, conducting repeated brain scans over three years to provide the most detailed picture yet of the dynamic changes in the brain that occur over the course of pregnancy unfold.
Emerging evidence suggests that “mommy brain” may really exist, but it has nothing to do with pop culture’s idea that new mothers become cognitively fuzzy and absent-minded. Instead, neuroscientists are just beginning to document how Hormone drive a series of complex, coordinated changes that respond to the brain Parenthood prepare and optimize.
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When neuroscientist Liz Chrastil and her husband were ready to start a family, she insisted on doing some self-examination. With a team of collaborators who have also studied the brain during menopause and the menstrual cycle, she slipped into the scanner 26 times – before, during and after her pregnancy – providing an unprecedented insight into a transformative event in human biology , which has long been overlooked by science.
How does the brain change during pregnancy? Scientist shows it
Key areas in her cortex, the wrinkled outer layer of her brain, shrank and thinned and stayed that way long-term, while the highways connecting brain regions improved during pregnancy and returned to baseline after the birth of her son. The proof-of-concept experiment, which took place on Monday (September 16th) in the specialist journal Nature Neuroscience published showed how malleable Chrastil’s brain was from month to month.
The experience of becoming a mother affects a person’s “biology, cognition, self-confidence and place in society – and even the risk of brain loss in old age,” says Sharna Jamadar, a neuroscientist at Monash University in Australia was involved in the study, in an email. “Despite these massive changes that occur during pregnancy, we have little understanding of exactly what changes occur in the brain during this time.”
An expanded project to scan the brains of more expectant mothers has already been launched to test how universal these changes are and to address the deeper question of how changes in brain structure affect behavior or thinking. The hope is that such studies could ultimately provide clues as to why some women develop depression after giving birth, or shed light on how pregnancy prepares the brain for aging.
“Mommy brain” isn’t what you think
Pregnancy is a pivotal point in human existence, but the maternal brain has been understudied and underestimated. Most of what researchers know about it comes from snapshots taken before and after pregnancy.
The new study agreed well with what was known from this research. There was a widespread and long-lasting reduction in the volume of gray matter, where brain cells are concentrated and thoughts, sensations and memories are rooted. These changes lasted two years after the birth of Chrastil’s son, and similar changes have been documented as lasting long-term in other studies.
<img class="id-RatioPlaceholder-element wv_story_el_image" src="https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg1BG.jpg" loading="lazy" srcset="https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg1b9.jpg 448w,https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg173.jpg 768w,https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg1BG.jpg 1100w,https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg17d.jpg 1408w,https://www.fr.de/assets/images/35/650/35650902-liz-chrastil-eine-kognitive-neurowissenschaftlerin-an-der-university-of-california-in-irvine-liess-ihr-gehirn-vor-waehrend-und-nach-ihrer-1xKLZinrg1PH.jpg 1600w" sizes="(min-width: 769px) 768px, 100vw" height="619" width="1100" alt="Liz Chrastil, a cognitive neuroscientist at the University of California, Irvine, had her brain scanned before, during and after her pregnancy. Your son is now 4 years old. “/>Liz Chrastil, a cognitive neuroscientist at the University of California, Irvine, had her brain scanned before, during and after her pregnancy. Your son is now 4 years old. © Liz Chrastil
Connections between brain regions strengthen during pregnancy
But because this team studied the brain itself during pregnancy, they were able to find something new: the integrity of the connections between brain regions – the white matter – increased in the first and second trimesters and then reversed again after birth.
A shrinking brain may not sound like a good thing, but Susana Carmona, a neuroscientist at the Gregorio Marañón General University Hospital in Madrid who was not involved in the study, has found that the decrease in gray matter volume during pregnancy is associated with increased maternal attachment, suggesting that the brain is adapting to the challenge ahead.
Emily Jacobs, a neuroscientist at the University of California, Santa Barbara and one of the study’s leaders, compares this process to Michelangelo’s masterpiece “David.” “You start with that block of marble and remove it piece by piece – that cut can reveal the beauty underneath,” Jacobs said.
Gray matter in the brain shrank by about 4 percent during pregnancy
Chrastil said she didn’t feel like she had a “mother brain,” although she has the rare ability to quantify exactly how much her gray matter has shrunk – by about 4 percent. She pointed out that most new mothers are sleep-deprived, which could play a role in how well people perceive their brains to be functioning.
Margaret McCarthy, a neuroendocrinologist at the University of Maryland School of Medicine, said that based on what is known about other animals’ brains during pregnancy, the changes likely represent refinement, not loss. In mice, for example, hormones trigger the remodeling of brain circuits that make them responsive to young animals. “We know from animal research that the hormonal environment of pregnancy changes the brain to prepare it for motherhood,” McCarthy said.
The constantly evolving brain
The new work is part of a wave of studies showing how changeable the brain is – what neuroscientists call “plasticity.” It’s easy to think of the brain as a static organ, but research has shown that its ability to change and adapt is key to its function. During adolescence, brain cells are pruned in a process that improves its efficiency. But the brain also changes in adulthood and even over short periods of time.
One of the leaders of the new study, Laura Pritschet, a postdoctoral fellow in psychiatry at the University of Pennsylvania’s Perelman School of Medicine, went into the scanner every day for a month during her menstrual cycle and showed that brain networks remodel over the course of a month.
And that doesn’t just apply to women. The brains of first-time fathers also changed after the birth of their child, researchers have found. Sex hormones also fluctuate over the course of a day, and when researchers scanned a man’s brain at 7 a.m. and 8 p.m. over the course of a month, they also found evidence of rhythmic changes in brain connectivity.
Still, there is something particularly interesting that happens during pregnancy, where the magnitude of change over a short period of time is particularly dramatic. “Overall, this supports the reconceptualization of motherhood as one of the periods of highest neuroplasticity in adult life,” Carmona said.
About the author
Carolyn Johnson is a science journalist. She previously reported on health care and health care affordability for consumers.
We are currently testing machine translations. This article was automatically translated from English into German.
This article was first published in English on September 16, 2024 at the “Washingtonpost.com“ was published – as part of a cooperation, it is now also available in translation to readers of the IPPEN.MEDIA portals.
