Pregnancy: a viral infection can lead to neuropsychiatric consequences in teens

Montreal - A Montreal study examines the mechanisms triggered in children whose mothers were infected with a virus during pregnancy, and which could cause neuropsychiatric disorders later in life. The research, recently published in the journal Biological Psychiatry, was conducted by doctoral student Elisa Guma, under the direction of Mallar Chakravarty, of the CoBrA Lab Brain Imaging Laboratory at the Douglas Research Center. Begun four years ago, the study focuses on neuropsychiatric mechanisms in children whose mothers have been infected with a virus during pregnancy. Although the study does not specifically look at COVID-19, its relevance has only increased with the pandemic, given the increased risk of being infected with a virus. It is already known that exposure to an infection—such as COVID-19—can have effects on fetal brain development. Rather than the virus itself, it is the antiviral immune activation of the mother that is a risk factor for the fetus. Infection during pregnancy can thus increase the risk for the child of developing neuropsychological problems during adolescence (autism, schizophrenia, depression). Examine the mechanisms on animal models To better understand the impact of immune system activation on offspring's brain development and behaviors, researchers tracked mouse brain development using magnetic resonance imaging (MRI). They also evaluated their behaviours. “The advantage of using a mouse model is that the gestation period is short, and their development is rapid,” Mallar Chakravarty explained in an interview with CTV on August 24. The researchers therefore examined the development of the brain of mice who were exposed to the virus in early and late pregnancy (the equivalent of the end of Q1 and the end of Q2 in humans). The transcriptomic study revealed that certain genes linked to the development of psychiatric disorders had been altered. The researchers also observed anxiety-like behaviors and stereotypical behaviors related to autism and schizophrenia in mice. Protecting the mother is protecting the child The researchers found that the earlier the infection occurred, the greater the risk to children. Exposure to the activation of the maternal immune system was thus associated with an acceleration of brain volume growth in adolescents and young adults. Fortunately, these effects wear off in adulthood, regardless of the time of in utero exposure. The alterations in behavior observed in adolescence (anxiety, stereotypical and sensorimotor behaviors) also resolve in adulthood. Also, an infection in the mother does not automatically mean that the fetus will be affected. Finally, note that animal models serve as indicators, and their conclusions cannot be applied as such to humans. While little is known about the long-term risks of COVID-19 for pregnant women and their babies, this study adds a stone in the edifice of understanding the effects of viruses on fetuses, and supports the importance for pregnant women to be vaccinated. Without being alarmist, it will still be necessary to keep an eye on future adolescents whose mothers were infected during pregnancy. Reference: Guma E., do Couto Bordinon P., Misic B., Bagot RC, Chakrabarty MM 2021. Early or Late Gestational Exposure to Maternal Immune Activation Alters Neurodevelopmental Trajectories in Mice: An Integrated Neuroimaging, Behavioral, and Transcriptional Study, Biological Psychiatry, 90 (5): 328-341. Originally ran on our sister brand in Quebec, Profession Santé. Translated from French.

Pregnancy: a viral infection can lead to neuropsychiatric consequences in teens

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