MRI study reveals never-before-seen changes in the brain during pregnancy

Researchers at the University of California, Santa Barbara, have compiled a neurological map of how the human brain changes throughout the duration of pregnancy. 

While prior imaging studies have compared changes that occur in the brain before pregnancy and after childbirth, this latest analysis is the first to span multiple time points during the full gestational period. Experts shared their findings this week in Nature Neuroscience. 

“Pregnancy is a period of profound hormonal and physiological changes experienced by millions of women annually, yet the neural changes unfolding in the maternal brain throughout gestation are not well-studied in humans,” lead author Laura Pritschet, PhD, from the Department of Psychological & Brain Sciences at UC Santa Barbara, and co-authors noted, adding that prior research has left gaps in understanding neural changes throughout pregnancy. 

For the study, the team conducted MRI brain exams on one first-time mother—a healthy 38-year-old woman with no history of neuropsychiatric issues or serious health conditions—for more than two years. The participant underwent a total of 26 MRIs, starting at three weeks prior to conception and ending two years after giving birth to a healthy, full-term baby. 

Through this, researchers were able to spot changes never before documented in pregnant women.  

Throughout the study, the group observed changes in both gray and white matter. Gray matter decreased as hormonal changes increased during gestation. The authors suggested that this could be a time of cortical “fine-tuning” when the brain reorganizes certain circuitry. This change persisted well into the postpartum months. 

In contrast to the gray matter finding, experts also noted a significant increase in white matter in deeper parts of the brain that are associated with communication between different regions. This finding—a first in pregnancy research—climaxed during the second trimester and returned to normal around the time of delivery. 

The group suggested that the neural changes “may have broad implications for understanding individual differences in parental behavior, vulnerability to mental health disorders and patterns of brain aging,” and could lay the groundwork for understanding issues mothers face after giving birth, such as postpartum depression. 

The study abstract can be found here.