Prenatal Stress Exposures Linked to Mitochondrial DNA Mutations in Infants, Study Suggests

Research conducted by the Icahn School of Medicine at Mount Sinai has uncovered a significant association between prenatal stress exposures and mitochondrial DNA mutations in infants. The study, published in the journal Biology of Sex Differences, found that higher mutational load in specific regions of placental mitochondrial DNA was positively associated with increased negative affectivity in infants. Notably, the findings revealed that girls were more susceptible to the adverse effects of these mutations, particularly under high maternal stress.

Key Takeaways:

• The study examined the association between placental mitochondrial DNA mutational load and negative affectivity in infants, and found a positive correlation between the two.
• Higher mutational load in the MT_CYB region was associated with increased negative affectivity in infants.
• Interactions between mtDNA regions (MT_DLOOP and MT_ND), child sex, and maternal stress revealed that girls with higher mutational loads in these regions were at greater risk for increased negative affectivity, particularly under high maternal stress.
• The findings suggest that placental mtDNA mutational load could serve as a biomarker for neurodevelopmental risk, with sex-specific vulnerabilities influenced by maternal stress.
• The study provides new insights into the potential role of the placenta as a tool for early detection and intervention in understanding early neurodevelopmental trajectories.

Statistics:

• 394 placenta samples were collected at delivery for analysis.
• 6.69 ± 1.61 months was the average age of children at the time of assessment.
• The study controlled for child sex, maternal age, self-reported race, and education in the multivariable regression analyses.
• 15% of U.S. children are impacted by neuropsychiatric and behavioral disorders.

Sources:

• Association of placental mitochondrial DNA mutations on infant negative affectivity: modifying effects of maternal lifetime stress and infant sex. Biology of Sex Differences, 2025,16(1):1-10.
• Icahn School of Medicine at Mount Sinai.
• National Institute of Health United States.
• National Institutes of Health.
• National Institute of Environmental Health Sciences.
• National Center For Advancing Translational Sciences.
• National Institutes of Environmental Health Sciences.