Summary:
Chronic stress during pregnancy fundamentally shifts how the placenta communicates with the fetus, altering vital antiviral immune signaling, cellular energy metabolism, and gene-regulatory programs. These placental changes, confirmed across both mouse models and human tissue, reveal a direct biological pathway connecting maternal psychological stress to elevated neurodevelopmental risks in offspring.
Key Facts:
- Placental Reprogramming: Chronic gestational stress alters crucial molecular pathways in the placenta, specifically disrupting cellular energy metabolism, antiviral immune defenses, RNA processing, and extracellular-matrix organization.
- Cross-Species Validation: Single-cell RNA sequencing in mice identified cell-specific stress responses that overlapped with genetic stress signatures identified in human placental tissue.
- Opposing Immune Impacts: Prenatal stress and infection-like immune activation were found to alter the exact same fetal-brain gene networks, but in opposite directions, revealing that different maternal insults disrupt shared neurodevelopmental programs in distinct ways.
Source: The Ohio State University Wexner Medical Center
Approximately one in five women in the United States experiences maternal mental health challenges. Decades of epidemiological studies have confirmed that chronic psychological stress during pregnancy increases the likelihood that a child will later develop cognitive, behavioral, or psychiatric disorders. However, the exact biological bridge transferring maternal stress across the gestational barrier into the fetal brain has remained elusive.
Now, a study led by researchers at The Ohio State University Wexner Medical Center and College of Medicine has identified a critical culprit: the placenta.
Published in Molecular Psychiatry, the research demonstrates that the placenta is far more than a passive vascular filter for nutrients and waste. Instead, it functions as a highly dynamic communication organ whose cellular signaling and energy pathways become significantly reprogrammed under chronic maternal stress, directly influencing early neurodevelopment.
Beyond a Passive Filter
During gestation, the placenta regulates the exchange of oxygen, nutrients, hormones, and waste products between mother and fetus. Because it forms the physical interface between two biological systems, researchers hypothesized that maternal stress signals might alter its underlying cellular machinery.
“The findings are quite remarkable. We found that the placenta isn’t simply a passive organ. It’s an active communication system between the mother and fetus,” said senior author Tamar Gur, MD, PhD, endowed director of the Soter Women’s Health Research Program and researcher with Ohio State’s Institute for Behavioral Medicine Research. “Our research suggests that stress can shift that communication in ways that may matter for brain development.”
To map these cellular shifts, the team used single-cell RNA sequencing in pregnant mouse models subjected to chronic stress. Because the placenta contains diverse cell lineages, including trophoblasts, endothelial cells, and immune cells, examining tissue on a single-cell level allowed the investigators to determine how distinct cell types respond to stress signaling.
The sequencing data revealed marked disruptions across several core systems:
- Antiviral Immune Pathways: Altered immune signaling that regulates how the placenta responds to pathogens and inflammatory cues.
- Cellular Bioenergetics: Dysregulated energy metabolism, impacting nutrient handling and cellular mitochondrial output.
- Gene-Regulatory Architecture: Shifts in chromatin remodeling, RNA processing, and structural extracellular-matrix organization.
Confirmation in Human Tissue
To verify that these animal findings translated to human biology, the researchers examined human placental tissue for corresponding molecular markers.
“In the human placentas, we saw stress-related signals that overlapped with key findings from the mouse studies, which strengthened our confidence that we were identifying biologically meaningful pathways,” Gur explained.
During the analysis, the team made an unexpected discovery when comparing psychological stress to physical infection. While prenatal psychological stress and infection-like immune activation impacted the exact same fetal-brain gene networks, they did so in opposite directions. This finding demonstrates that while different maternal environmental challenges converge on the same neurodevelopmental circuits, they alter their expression in distinct ways.
Toward Interventions That Block Stress Transmission
By mapping the exact molecular cascades that shift within the placenta, the researchers hope to lay the foundation for targeted interventions that shield fetal neurodevelopment from maternal stress.
Future work from the Ohio State team will explore whether pharmacological or nutritional modulation of specific placental energy and immune pathways can rescue fetal brain development during periods of high gestational stress or immune challenge. The researchers also plan to evaluate larger human cohorts to determine how the specific timing, duration, and intensity of stress exposure across trimesters alters these biological signals.
“We now know that pathways that help with stress are being altered,” Gur noted. “If we can uncover more of those pathways, then maybe we can target a therapy that can help stop the transmission of stress.”
Funding: The research was funded by the National Institutes of Health and the Soter Women’s Health Research Program.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this Neurodevelopment Research:
- Media Contact: Allison Matthews
- Source: Ohio State University
- Image Credit: Image credited to Neuroscience News
- Original Research is Open Access: Molecular Psychiatry (Oct 1, 2026). “Prenatal stress reprograms placental signaling and opposes maternal immune activation effects in the fetal brain.” Authors: Branden G. Verosky, Helen J. Chen, Jessica L. Anderson, Therese A. Rajasekera, Maya Neidhart, Suhanna Halaharvi, Brett L. Worly, Andy J. Fischer & Tamar L. Gur.
- DOI: 10.1038/s41380-026-03914-8
Abstract
Prenatal stress reprograms placental signaling and opposes maternal immune activation effects in the fetal brain
Prenatal psychosocial stress and maternal immune activation (MIA) increase risk for overlapping offspring psychiatric disorders, but whether they influence fetal neurodevelopment through shared or distinct mechanisms is unclear. Positioned at the interface of maternal and fetal physiology, the placenta has a critical role in regulating fetal brain development.
Here, we combine mouse placental single-cell RNA sequencing, transcriptomics of matched placentas and fetal brains, maternal cytokine profiling, and human placental RNA-seq to dissect this axis. In mice, chronic stress suppressed interferon signaling across placental immune cells and downregulated oxidative phosphorylation pathway expression in trophoblasts.
Stressed dams also mounted a blunted type I interferon response to poly(I:C), resulting in attenuated placental antiviral signaling. Weighted gene co-expression analysis of fetal brains revealed that prenatal stress and MIA regulate overlapping DNA repair, synaptic, and translational networks in opposite directions, with stress promoting signatures of premature maturation and MIA driving replication stress.
In human placentas, higher perceived stress was associated with chromatin-regulatory, RNA-metabolic, and extracellular-matrix modules that mirrored the murine stress signature. These findings identify a conserved placental stress-associated transcriptional program and suggest that stress and MIA affect shared neurodevelopmental pathways in opposing directions.
