Epigenetic Changes Connect Maternal Infection During Pregnancy to Increased Schizophrenia Risk in Offspring

Recent research highlights the significant impact of maternal infections during pregnancy on the neurodevelopment of offspring, potentially leading to an elevated risk of developing schizophrenia. Schizophrenia is a severe mental disorder characterized by hallucinations, delusions, and cognitive impairments. Scientists from the University of Manchester and Manchester Metropolitan University conducted a comprehensive study to understand how infections during pregnancy might influence the brain development of unborn children through epigenetic mechanisms—biological processes that modify gene activity without changing the DNA sequence itself.

The study, published in Molecular Psychiatry, focused on the role of maternal immune activation (MIA) and its effects on the fetus. When a pregnant woman contracts an infection—bacteria, viruses, fungi, or parasites—her immune system reacts, which can indirectly affect fetal development. The researchers used rat models to analyze changes in epigenetic markers, particularly focusing on DNA methylation patterns and enzyme activity involved in gene regulation.

Their findings revealed that maternal immune activation increased the ratio of S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH), molecules critical for methylation processes in cells. Elevated SAM/SAH ratios led to increased activity of DNA methyltransferases (DNMTs), enzymes that add methyl groups to DNA, affecting gene expression. These epigenetic alterations were not only present during prenatal development but reemerged in adulthood, coinciding with observable cognitive deficits reminiscent of schizophrenia.

Furthermore, the study identified that these methylation changes affected genes associated with schizophrenia risk, especially those involved in neurodevelopment and neuronal signaling pathways. The findings suggest that maternal infections induce epigenetic modifications in the fetal brain, which may predispose offspring to neurodevelopmental disorders like schizophrenia.

This research advances our understanding of how immune responses during pregnancy can influence long-term mental health outcomes and underscores the importance of preventing infections during pregnancy. Future studies could pave the way for novel preventative strategies and targeted therapies to mitigate the risk of schizophrenia linked to maternal health during pregnancy.

For more detailed information, see the full study here. Source: https://medicalxpress.com/news/2025-10-epigenetic-shifts-link-maternal-infection.html