Scientists reveal the countless ways pregnancy alters the brain

Neuroscientist Liz Chrastil has embarked on a remarkable journey, providing insights into how pregnancy influences brain structure. Her recent study presents the first comprehensive mapping of a woman’s brain during the transformative process of gestation.

This research indicates that the transition to motherhood triggers significant changes across nearly every area of the brain.

While the study primarily focuses on Chrastil, it is the beginning of an expansive international initiative aimed at scanning the brains of hundreds of women. This project could ultimately yield valuable information regarding disorders such as postpartum depression.

“It’s been a very long journey,” Chrastil expressed. She is a co-author of a paper published in *Nature Neuroscience*. “We conducted 26 scans throughout the different stages: before, during, and after pregnancy,” revealing “some really remarkable things.”

The findings indicate more than 80% of the brain regions analyzed experienced a reduction in the volume of gray matter, the area responsible for processing thoughts. The average reduction was about 4% of the brain’s volume, a change comparable to what occurs during puberty. While it might seem concerning that gray matter declined, researchers emphasized that this is likely a result of the brain optimizing its neural circuits, preparing for this new chapter in life.

Chrastil, who was 38 years old at the onset of her pregnancy through in vitro fertilization, underwent regular MRI scans and blood tests throughout her pregnancy and two years postpartum to examine the influence of fluctuating sex hormones, such as estrogen, on her brain.

“Previous studies have only captured snapshots of the brain pre- and post-pregnancy, but we have the opportunity to witness the brain as it undergoes this significant transformation,” said Emily Jacobs, a co-author and researcher at the University of California, Santa Barbara.

This study distinguishes itself by exploring not only the cerebral cortex, the brain’s outer layer, but also numerous internal regions. Joseph Lonstein, a neuroscience and psychology professor at Michigan State University, remarked on the importance of this approach, calling it “a good first step to understanding much more about whole-brain changes that could occur in women during pregnancy and postpartum.”

Prior research on animals has suggested that certain brain changes could enhance parental caregiving abilities. Although the current study does not delve into the implications of these changes on human behavior, Lonstein highlighted that the research details alterations in brain regions pivotal for social cognition, such as the ability to interact with others and comprehend their emotions and thoughts.

Collaborating with researchers in Spain, the team is advancing the Maternal Brain Project, which has backing from the Ann S. Bowers Women’s Brain Health Initiative and the Chan Zuckerberg Initiative.

Through this extensive research effort, the ultimate goal is to equip scientists with data that can help predict postpartum depression before it manifests.

“There is still much to uncover about the neurobiology of pregnancy,” Jacobs remarked. “This gap in understanding is not due to the inherent complexity of women or pregnancy itself; rather, it stems from the historical oversight of women’s health in biomedical sciences.”

This groundbreaking research suggests significant implications for understanding motherhood from a neurological perspective. The ongoing work promises to provide deeper insights into how the brain adapts during one of life’s most profound transitions.