Translation. Region: Russian Federation –
Source: Peter the Great St. Petersburg Polytechnic University –
An important disclaimer is at the bottom of this article.
Influenza virus infection during pregnancy poses significant risks to the health of the mother and fetus and may contribute to adverse neuropsychiatric outcomes in the offspring. Epidemiological studies conducted over the years have linked influenza in pregnant women with an increased risk of autism spectrum disorders, schizophrenia, and cognitive deficits in the child later in life. A study by a team of St. Petersburg scientists demonstrated that the underlying cause is not the virus itself, but rather the mother's protective response. Understanding these mechanisms may help develop strategies to reduce the risks of neurodevelopmental impairment associated with prenatal infections. The study was supported by the Ministry of Science and Higher Education and the Ministry of Health. The results were published in the scientific journal Frontiers in Cellular and Infection Microbiology.
Seasonal influenza causes between 3 and 5 million severe cases of illness worldwide each year, and its danger to pregnant women is particularly high. During the 2009 H1N1 pandemic, for example, it was found that the infection could lead to premature births and low-birth-weight babies. Other adverse effects of influenza on pregnant mothers include preterm birth, low birth weight, increased risk of infant mortality, weakened respiratory immunity, and, in some cases, various neurodevelopmental disorders (including schizophrenia, psychotic or psychosis-like states, mood disorders, developmental delays, and bipolar disorder). Scientists worldwide are investigating the specific mechanisms underlying the development of such complications, but the detailed mechanism has not been fully elucidated. Most studies suggest that the influenza virus is generally unable to cross the placenta.
An interdisciplinary team of St. Petersburg scientists conducted a detailed study of the mechanism by which adverse effects on the fetus occur due to maternal influenza infection during pregnancy using an animal model of the infection. The study involved scientists from Peter the Great St. Petersburg Polytechnic University, the A. A. Smorodintsev Influenza Research Institute, and the I. P. Pavlov Institute of Physiology of the Russian Academy of Sciences. The scientists examined the effects of infection with two strains of the A(H1N1) influenza virus during pregnancy using an animal model (mice). Severe infection led to a sharp decrease in offspring survival—from the normal 92% to 20–46%. Even the surviving offspring showed significant disruptions in brain development. The primary focus of the study was the hippocampus, a brain region responsible for memory formation, learning, and emotional regulation. It is in the hippocampus that the process of new nerve cell formation—neurogenesis—actively occurs throughout the perinatal period and into adulthood.
The study found that the most serious adverse effects on the fetus were caused not by the influenza virus itself, but by the inflammatory response it triggered in the mother's body, which led to disruption of neurogenesis.
We found that inflammatory signals from the mother's body led to two critical consequences: suppression of neurogenesis and chronic activation of glial cells. The offspring of mice that had experienced an influenza infection during pregnancy had a decreased number of neuronal stem and progenitor cells, which potentially impacts nerve cell formation. At the same time, it was shown that glial cells, which normally perform protective and supportive functions, entered a constantly activated, "inflammatory" state in key areas of the hippocampus, creating an unfavorable environment for neuronal development. This may be one of the mechanisms for the development of potential serious neurocognitive disorders in the future, noted Anastasia Rakovskaya, a research engineer at the Molecular Neurodegeneration Research Laboratory at the Institute of Biomedical Systems and Biotechnology at SPbPU.
The study not only explains the observed link between influenza infection during pregnancy and the development of possible neurological complications in the future, but also suggests specific ways to protect the health of future generations.
Of course, the results of studies obtained on laboratory animals cannot be directly transferred to humans. However, given the available clinical data and the results of our work, we can formulate clear practical conclusions: 1. Vaccination of pregnant women against influenza should be a mandatory and primary preventative measure. 2. In the event of illness, antiviral therapy should be initiated as early as possible to suppress viral replication and, consequently, reduce the severity of the inflammatory response. 3. The development of safe drugs capable of selectively blocking proinflammatory cytokines in pregnant women is necessary, which could open a new direction in the development of anti-inflammatory drugs, said Yana Zabrodskaya, PhD in Physics and Mathematics and Associate Professor at the Higher School of Biomedical Systems and Technologies at the Institute of Biomedical Systems and Biotechnology at SPbPU.
The implementation of the above measures will not only prevent long-term consequences for the child, but will also provide a significant economic effect, saving money on the treatment of possible mental and neurological disorders in the future.
All experiments were carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation (state assignment No. FSEG-2023-0014), with the exception of measurements of the expression of proinflammatory cytokine genes, which were funded by the Ministry of Health of the Russian Federation (state assignment No. 056-00025-25-01, topic No. 123021300165-6).
Please note: This information is raw content obtained directly from the source. It represents an accurate account of the source's assertions and does not necessarily reflect the position of MIL-OSI or its clients.