Pregnancy is a profoundly understudied period of growth and development that millions of women each year experience. During this time, the body undergoes extreme hormonal and physical changes that are similar in magnitude to the overhaul seen during puberty. Previous studies on the effects of pregnancy on the brain have only yielded a snapshot comparison between women’s brains before and after pregnancy, an approach that has given little information on this topic. Earlier this month, Dr. Elizabeth Chrastil of the University of California Irvine conducted a study in collaboration with other researchers wherein neuroimaging techniques were used to track her brain through her own pregnancy in order to create the first comprehensive map of her brain’s evolution through pregnancy.
The team who conducted this study performed 26 different MRI scans before, during, and after Dr. Chrastil’s pregnancy and compared those scans to other non-pregnant women in order to map the brain’s changes. They conducted “four MRI scans before pregnancy, 15 scans during pregnancy and seven scans in the two years after the baby was born”, writes Laura Sanders of ScienceNews. This approach covered the entire arc of the pregnancy and gave insight into its lasting effects on the brain, which can help us to understand the causes of postpartum mental health issues that are common amongst mothers.
Previous research has noted a decrease in gray matter, a tissue composed of cell bodies and dendrites that controls movement, memory, sensation, and emotions. The research team confirmed this in their study, where they found that the volume of gray matter was reduced in “80 percent of the places in the brain […], shrinking on average by about 4 percent of its starting bulk”, writes Sanders. Areas with the highest loss of gray matter, and loss of thickness in the cerebral cortex, included the, “default mode network, which is associated with social cognitive functions”, writes Kristen Rogers of CNN. The scans from the study also revealed“increases in cerebrospinal fluid and white matter microstructure in the second and third trimesters”. White matter helps areas of the brain communicate with each other, and cerebrospinal fluid provides “nourishment, protection, and waste removal for the brain”, said Rogers. Drops in both of these areas have been linked to the rising levels of estradiol and progesterone, two hormones that play a major role in reproduction.
In the two years following her giving birth, some of the changes seen in Dr. Chrastil’s brain had reverted back to normal. Others, including gray matter volume and cortical thickness, remained the same as they were during the pregnancy.
This study not only lays the groundwork for future research in pregnancy-related neurological studies, but also makes note of various dynamical changes that affect women during and after pregnancy. Experts say that while findings of this study have been corroborated with the experiences of other pregnant women, larger-scale research has to be conducted to strengthen the conclusions drawn. Findings from this study support some methods that can be used to help women physically and mentally prepare for pregnancy in order to prevent common complications. Results about the lasting impact of pregnancy give way to the study of the reasons for postpartum depression and other mental health issues new mothers express, allowing us to predict them before they happen.
What used to be jokingly referred to as “pregnancy brain” is now a phenomenon being analyzed using advanced imaging, computer algorithms, and other biomedical innovations. Emily Jacobs of University of California Santa Barbara, who worked on this study, told CNN, “of the 50,000 brain imaging articles published in the last 30 years, less than half of 1% focus on health factors unique to women, like pregnancy.” Ignorance on the topic of women’s brain health through pregnancy has prevented doctors from predicting mental health and physical complications of new mothers. Results of this study are being analyzed by scientists around the world, as an international effort called the Maternal Brain Project was launched to further pregnancy research. Supporters include UC Santa Barbara’s Ann S. Bowers Women’s Brain Health Initiative and the Chan Zuckerberg Initiative. A push for a better understanding of pregnancy will help improve care for new and expectant mothers.
