Summary:
Chronic psychological stress during pregnancy remodels how the placenta communicates with the fetus, changing antiviral immune signaling, cellular energy metabolism, and gene-regulatory programs. These placental alterations, demonstrated in both mouse models and human placental tissue, provide a direct biological pathway linking maternal stress to increased neurodevelopmental risk in offspring.
Key Facts:
- Placental Reprogramming: Prolonged gestational stress rewires core molecular pathways in the placenta, disrupting cellular bioenergetics, antiviral immune defenses, RNA processing, and extracellular-matrix organization.
- Cross-Species Validation: Single-cell RNA sequencing in mice uncovered cell-type specific stress responses that matched stress-related transcriptional signatures observed in human placentas.
- Opposing Immune Impacts: Prenatal psychological stress and infection-like maternal immune activation influence the same fetal-brain gene networks but in opposite directions, indicating distinct modes of disruption on shared neurodevelopmental programs.
Source: The Ohio State University Wexner Medical Center
Background: Approximately one in five women in the United States experiences maternal mental health challenges. Long-standing epidemiological research shows that persistent psychological stress during pregnancy is associated with higher odds that a child will later face cognitive, behavioral, or psychiatric disorders. Until now, the precise biological pathway that transmits maternal stress across the placenta into the developing fetal brain has been unclear.
New research led by investigators at The Ohio State University Wexner Medical Center and College of Medicine identifies the placenta as a key mediator. Published in Molecular Psychiatry, the study demonstrates that the placenta is an active signaling organ whose cellular communication and energy pathways are significantly reprogrammed by chronic maternal stress, with direct implications for early brain development.
Beyond a Passive Filter
The placenta performs vital functions—exchanging oxygen, nutrients, hormones, and waste between mother and fetus. Because it sits at the interface of two biological systems, researchers proposed that maternal stress signals could alter the placenta’s cellular machinery and downstream effects on the fetus.
“These findings are striking. The placenta is not merely a passive filter; it acts as an active communication hub between mother and fetus,” said senior author Tamar Gur, MD, PhD, endowed director of the Soter Women’s Health Research Program and a researcher at Ohio State’s Institute for Behavioral Medicine Research. “Our results indicate that stress shifts that communication in ways that can matter for brain development.”
To chart these changes, the team applied single-cell RNA sequencing to placentas from pregnant mice exposed to chronic stress. Because the placenta contains multiple cell types—trophoblasts, endothelial cells, and immune cells—single-cell analysis allowed the researchers to pinpoint how individual lineages respond to stress signals.
The sequencing revealed pronounced disruptions in several core biological systems:
- Antiviral Immune Pathways: Stress altered interferon-related signaling and other immune responses that control how the placenta reacts to pathogens and inflammation.
- Cellular Bioenergetics: Energy metabolism became dysregulated, affecting nutrient handling and mitochondrial activity in key placental cell populations.
- Gene-Regulatory Architecture: Stress influenced chromatin remodeling, RNA processing, and the organization of extracellular-matrix components, reshaping gene expression programs.
Confirmation in Human Placental Tissue
To ensure the findings were relevant to human biology, the investigators examined human placentas for matching molecular signatures. They found stress-associated transcriptional programs in human tissue that mirrored the murine patterns, lending confidence that the identified pathways are conserved across species.
An unexpected but important discovery emerged when the team compared the effects of psychological stress with maternal immune activation that mimics infection. Both types of maternal challenges targeted the same fetal-brain gene networks—DNA repair, synaptic machinery, and translational control—but they pushed those networks in opposite directions. Prenatal stress produced signatures consistent with accelerated or premature maturation, whereas immune activation produced signs of replication stress. This divergence suggests that different maternal environmental insults can converge on shared neurodevelopmental circuits while producing distinct molecular consequences.
Toward Interventions to Prevent Stress Transmission
By delineating the exact molecular cascades altered in stressed placentas, the researchers aim to pave the way for targeted interventions that protect fetal brain development. Future work will test whether pharmacological or nutritional modulation of specific placental energy and immune pathways can reverse or mitigate stress-induced effects during pregnancy.
The Ohio State team also plans larger human cohort studies to determine how the timing, duration, and severity of maternal stress across trimesters influence these placental and fetal signals. “We now know that pathways that help with stress are being altered,” Gur said. “If we can identify more of those pathways, we may be able to develop therapies that interrupt stress transmission to the fetus.”
Funding: The research was supported 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.
- The journal paper was reviewed in full by the editorial team.
- Additional context was provided by staff editors to clarify implications and study design.
About this Neurodevelopment Research:
- Media Contact: Allison Matthews
- Source: Ohio State University
- Image Credit: Image credited to Neuroscience News
- Original Research (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) both raise the risk of overlapping psychiatric outcomes in offspring, but it has been unclear whether these maternal exposures act through shared or distinct mechanisms. The placenta, positioned between maternal and fetal systems, plays a pivotal role in shaping fetal brain development.
This study integrates mouse placental single-cell RNA sequencing, combined transcriptomics of matched placentas and fetal brains, maternal cytokine profiling, and analysis of human placental RNA-seq to interrogate this maternal–placental–fetal axis. In mice, chronic stress suppressed interferon signaling across placental immune cells and reduced oxidative phosphorylation pathway expression in trophoblasts. Stressed mothers also showed a muted type I interferon response to poly(I:C), diminishing placental antiviral signaling.
Weighted gene co-expression analysis of fetal brains demonstrated that prenatal stress and MIA regulate overlapping networks involved in DNA repair, synaptic function, and translation in opposite directions: stress promoted signatures resembling premature maturation, while MIA induced features of replication stress. In human placentas, higher perceived stress correlated with chromatin-regulatory, RNA-metabolic, and extracellular-matrix transcriptional modules that resembled the murine stress signature. Together, these results identify a conserved placental stress-associated program and indicate that stress and immune activation affect shared neurodevelopmental pathways in opposing ways.