Health Care

Scans show reorganization of brain during pregnancy

Pregnancy appears to trigger a kind of “reorganization” of an expecting mother’s brain, new research suggests.  

MRI images taken of a 38-year-old woman throughout her pregnancy show the condition caused an extensive restructuring of her brain, according to a proof-of-concept study published Monday in the journal Nature Neuroscience.  

As part of the study, neuroscientist and first-time mother Elizabeth Chrastil underwent 26 magnetic resonance imaging scans (MRIs). The first was taken three weeks before she became pregnant via in vitro fertilization and the last captured two years after giving birth, according to the study.  

The brain is made up of two types of material — gray matter and white matter. When researchers looked at Chrastil’s MRI scans, some of the changes they noticed were a decrease in grey matter — or the wrinkly outermost layer of the brain.  

Another change was an increase in white matter — which is located deeper in the brain and is essentially a network of nerve fibers that enable parts of the brain to communicate with one another.  


Researchers noted that while many of the changes returned to baseline after childbirth, some, like cortical volume and thickness, remained altered in the postpartum years.  

Scientists have previously taken images of a woman’s brain before and after pregnancy, which have provided the strongest evidence to date that the human brain undergoes neural changes during pregnancy, according to Laura Pritschet, a postdoctoral fellow in psychiatry at the University of Pennsylvania Perelman School of Medicine and lead author of the study. 

But research on pregnancy is often ignored in the scientific community, and as a result, the neuroanatomical changes that occur during gestation are “virtually unknown,” Pritschet told The Hill.  

The newly released research findings offer a glimpse into the “profound hormonal and physiological changes” that come with pregnancy and how they impact the roughly 140 million women worldwide who become pregnant every year. 

During a pregnancy, a soon-to-be mother’s body undergoes numerous physical changes to support a developing fetus like increased plasma volume, increased metabolic rate and oxygen use.  

Most of these changes are triggered by major increases in certain hormone production — including estrogen and progesterone — which appears to also drive the “remodeling” of the central nervous system the researchers noticed in their study.  

More research is needed though to fully understand the degree to which the brain changes throughout pregnancy, Pritschet said.  

“Our hope is that this proof-of concept study serves as a jumping off point for more studies that take place in larger, more diverse cohorts of women,” she said in an email. “Only then can we begin to establish what constitutes a typical degree of neuroanatomical change expected during gestation and postpartum recovery.”