Neuroscientist Liz Chrastil had a rare opportunity to observe the changes in her brain during pregnancy and to share her findings in a groundbreaking study that presents the first comprehensive mapping of a woman's brain throughout gestation.

Researchers found that the journey into motherhood impacts nearly every area of the brain.

While the study focuses on a single individual, it marks the beginning of a significant international research initiative aimed at scanning the brains of hundreds of women, potentially offering insights into conditions such as postpartum depression.

“It’s been a very long journey,” stated Chrastil, co-author of the paper published on Monday in Nature Neuroscience. “We conducted 26 scans before, during, and after pregnancy” and discovered “some truly remarkable findings.”

Over 80% of the brain regions examined showed a decrease in gray matter volume, which is associated with cognitive functions. This reduction averaged about 4% of the brain, closely resembling the changes observed during puberty. Although a decrease in gray matter might seem concerning, researchers suggest it likely indicates the refinement of neural circuits in preparation for a new life stage.

The research team began monitoring Chrastil—who is affiliated with the University of California, Irvine and was 38 at the time—just before her pregnancy through in vitro fertilization. They continued to perform MRI brain scans and blood tests during her pregnancy and for two years following childbirth to track how her brain evolved with fluctuating sex hormones like estrogen. Some changes persisted beyond the pregnancy period.

“Previous research had only captured the brain's state before and after pregnancy, but we have now observed the brain during this transformative process,” remarked co-author Emily Jacobs from the University of California, Santa Barbara.

In contrast to previous research, this study examined various inner brain regions in addition to the cerebral cortex, the brain's outermost layer, according to Joseph Lonstein, a professor of neuroscience and psychology at Michigan State University who was not part of the study.

In this photo provided by Liz Chrastil, a neuroscientist with the University of California, Irvine, she her holds her newborn son in May 2020. (Courtesy Liz Chrastil via AP)

He remarked that this represents "a significant initial step toward gaining a deeper understanding of the comprehensive brain changes that may occur in women during pregnancy and the postpartum period."

Animal studies have associated certain brain alterations with traits beneficial for infant care. Although the current study does not directly link these changes to human behavior, Lonstein emphasized that it highlights modifications in brain regions related to social cognition, which encompasses how individuals engage with others and interpret their thoughts and emotions.

The research team is collaborating with partners in Spain and advancing the larger Maternal Brain Project, which receives support from the Ann S. Bowers Women’s Brain Health Initiative and the Chan Zuckerberg Initiative.

Ultimately, the researchers aspire to enable scientists to utilize data from a substantial cohort of women to predict conditions such as postpartum depression before they manifest.

Jacobs noted, "There is still much to learn about the neurobiology of pregnancy, and this gap in knowledge is not due to the complexity of women or pregnancy being an insurmountable challenge. Rather, it stems from the historical neglect of women's health in biomedical sciences."

AP