Lila Metherate
Contributing Writer
Pregnancy is a period of tremendous physical and mental change in a woman’s life. It was previously unknown, however, what changes actually occur in the brain over the course of gestation. Research within this field has mostly focused on differences between the brain preconception and the brain postpartum, without much consideration for what occurs during pregnancy. Luckily, a new study conducted in collaboration between UC Santa Barbara’s associate professor Emily Jacobs, Ph.D., and UC Irvine’s Elizabeth Chrastil, Ph.D., sheds light on the dramatic changes the human brain undergoes during pregnancy. The Bottom Line (TBL) sat down with Hannah Grotzinger, a Ph.D. student from the Jacobs Lab, to learn more.
The study used magnetic resonance imaging (MRI) to scan the brain of one participant periodically from three weeks preconception until two years postpartum. The series of MRI scans showed that the brain underwent significant anatomical changes, such as decreases in gray matter volume and cortical thickness across the brain, as well as some increases in white matter microstructures, ventricle volume, and cerebrospinal fluid. When TBL asked what the purpose of these changes may be, Grotzinger commented, “I think it’s tough to know because we don’t have other behavioral metrics that we’re tracking alongside it … it’s too soon to say anything too conclusive. It’s showing that we need more research on a cellular level to really know why that might be happening.”
Grotzinger highlighted that the most robust structural changes were in specific midline, prefrontal, and parietal regions of the brain. “These [regions] are involved in a lot of different social processes,” she explained, “for one, theory of mind processing, so being able to understand someone else’s wants and needs and that others might have different points of view from your own, is a crucial skill for parenting.”
These structural changes may reflect a fine-tuning in the brain to promote skills relevant for parenthood. A connection between neuroanatomical changes and maternalistic behavioral changes during pregnancy has been observed in rodent studies, however, further research is needed to confirm this connection among humans.
When asked about next steps, Grotzinger explained to TBL that she is currently expanding the study to include more participants and more controls, and also plans to scan the brains of non-pregnant partners. “One partner is completely going through this massive physiological change and the other one is observing it happening, and so it’ll be really cool to compare those two trajectories and see how it’s unfolding,” she shared with TBL. Grotzinger hopes to be able to tease out how much of these neurostructural changes are due to biological factors versus behavioral or environmental factors.
On a broader scale, the Jacobs Lab aims to understand how demographic and social variables around the world can impact changes during pregnancy. Grotzinger stated that they are “really interested in how different policies like maternity leave and how different healthcare systems … might impact these changes.”
By providing a comprehensive understanding of the neuroanatomical changes that occur over gestation, this study has made a profound contribution to women’s health. It uncovers some of the mysteries surrounding pregnancy and offers women a deeper look into the changes they are undergoing. Future research in this field may focus on how neurostructural changes during gestation could relate to postpartum depression, parental attachment, and dementia. Hopefully, the high volume of positive response this study has received will spark funding to continue exploring these research avenues.