Pregnancy induces significant transformations in a woman’s body, but a new study highlights substantial changes in the brain as well. Researchers from the University of California, Irvine, have mapped these neurological shifts for the first time, using brain scans taken 26 times starting three weeks before conception, throughout the nine months of pregnancy, and extending two years postpartum.
The study found a widespread average decrease of 4% in cortical gray matter across approximately 80% of the brain regions examined, alongside a 10% increase in the microstructural integrity of white matter. These changes coincided with rising levels of the hormones estradiol and progesterone, crucial during pregnancy. Gray matter, composed of nerve cell bodies, and white matter, which consists of axons that connect different brain areas, both play vital roles in brain function.
Elizabeth Chrastil, a cognitive neuroscientist and co-author of the study, served as the primary subject, documenting her experience as a first-time mother. Although the initial study was limited to her, researchers have since observed similar patterns in other pregnant women involved in the ongoing Maternal Brain Project, aiming to expand the research to hundreds of participants.
“This research opens more questions than it answers,” said Chrastil, emphasizing the scarcity of information on pregnancy’s impact on the brain. The study suggests that the reduction in gray matter may not be detrimental, potentially indicating a fine-tuning of brain circuits similar to processes seen during puberty.
Emily Jacobs, a senior author of the study published in Nature Neuroscience, noted the importance of observing these changes in real time, contrasting it with previous research that offered only pre- and post-pregnancy snapshots.
Researchers also aim to explore how these neurological changes may correlate with conditions like postpartum depression and preeclampsia. Chrastil reflected on her experience, stating she was unaware of the brain changes during the study and did not feel significantly different, despite common perceptions of “Mommy Brain.”
