Pregnancy Triggers Widespread Brain Changes, New Research Confirms
A series of research initiatives have produced findings showing that pregnancy is associated with significant structural and functional changes in the human brain. Two separate studies—the Maternal Brain Project (MBP) led by the University of California, Santa Barbara, and research conducted at Amsterdam UMC—have released data detailing the nature and extent of these alterations during first and subsequent pregnancies.
Maternal Brain Project Findings
The Maternal Brain Project, led by neuroscientist Emily Jacobs at the University of California, Santa Barbara (UCSB), tracked a participant through pregnancy using brain scans. The preliminary findings detected widespread volume reductions and alterations in the cerebrovascular system.
"Approximately 97% of the 400 brain regions examined showed changes across gestation and after birth."
According to the MBP data:
- Total brain volume, gray matter volume, and cortical thickness decreased significantly during pregnancy, with partial rebound after childbirth.
- Cerebrospinal fluid levels followed the opposite pattern, increasing during pregnancy.
- Changes were consistent across participants and occurred in regions including the superior temporal lobes, midline, prefrontal cortex, and subcortical areas.
The MBP was launched following a 2024 case study that revealed brain metamorphosis during pregnancy. Jacobs noted that since 1990, approximately 0.5% of brain scan studies have focused on women's health.
The project has expanded to include 20 participants—including first-time mothers, second-time mothers, fathers, and non-pregnant women—across multiple institutions in the United States and Spain. Researchers are conducting regular MRI scans, blood draws, and questionnaires over an 18-month period. Future goals include establishing an open-access maternal brain database to study effects on cognition, postpartum depression, and pregnancy complications.
Amsterdam UMC Research on First and Second Pregnancies
Researchers at Amsterdam UMC determined that a second pregnancy also alters the female brain. The findings, published in Nature Communications, build on previous research from the same group that demonstrated the impact of a first pregnancy. The study tracked 110 women, including first-time mothers, women having a second child, and a control group of individuals who had not given birth. Repeated brain scans were used to observe changes.
During a first pregnancy, the most significant changes were observed in the structure and activity of the Default Mode Network, which is involved in self-reflection and social processes. This network also changed during a second pregnancy, but the alterations were less pronounced. A second pregnancy showed more changes in brain networks related to directing attention and responding to stimuli.
The study identified a link between brain changes and the mother-child bond, which was more prominent during a first pregnancy.
Connections between structural brain changes and peripartum depression were observed in both first and second pregnancies. For first-time mothers, this link was more evident after childbirth, whereas for women having a second child, it was particularly noticeable during pregnancy.
Implications and Ongoing Research
The Amsterdam UMC research offers insights into how the female brain adapts to motherhood. Researchers involved indicated the findings may contribute to improved maternal care, including the prevention and treatment of postpartum depression, and suggest the brain's capacity for flexibility and adaptation to significant life changes.