Recent research conducted at the University of Illinois Urbana-Champaign has underscored the potential risks associated with severe influenza infections during pregnancy, particularly concerning neurodevelopmental disorders in offspring. Contrary to the virus itself causing harm, the study reveals that the mother’s immune response plays a pivotal role in impacting fetal brain development.
Using live influenza A virus in mouse models, the researchers observed significant fetal brain changes, particularly when the severity of maternal infection reached a critical threshold. This finding emphasizes the importance of flu vaccination for pregnant women as a preventive measure to mitigate such risks. It also sheds light on the specific threshold of infection severity that correlates with adverse fetal brain impacts.
Lead study author Ashley Otero, a doctoral student in the Neuroscience Program at Illinois, highlighted the study’s innovative approach using live virus infection in mice, which closely mimics human flu outbreaks. This method provided deeper insights into the cellular and molecular processes underlying maternal influenza infections and their effects on fetal brain development.
“Our findings provide compelling evidence for an infection severity threshold, mirroring what we observe in human cases,” commented senior study author Adrienne Antonson, assistant professor in the Department of Animal Sciences. “Pregnant individuals should prioritize getting the flu vaccine to reduce these risks,” she added, emphasizing the critical role of vaccination in protecting maternal and fetal health.
The study also explored immune responses in maternal mice, noting increased inflammatory activity in fetal microglia and border-associated macrophages (BAMs) following severe infections. These immune cells, crucial for healthy brain development, exhibited signs of overactivity that could potentially disrupt neuronal development in the fetus.
“While our study excludes interleukin-17 as a key factor in these processes, it highlights the need for further research into BAMs’ role in prenatal influenza infection,” Otero explained. Understanding these mechanisms could lead to targeted interventions to safeguard fetal brain health during maternal infections.
Antonson cautioned that while maternal infection is a significant risk factor, neurodevelopmental disorders arise from a complex interplay of genetic, environmental, and other factors across various developmental stages. She emphasized the importance of comprehensive research spanning prenatal and postnatal periods to fully grasp the multifaceted nature of these disorders.
This study marks a crucial step in advancing our understanding of how maternal infections impact fetal neurodevelopment and underscores the urgency of vaccination and prenatal care to promote healthy outcomes for both mothers and babies.
