Studying the placenta to better understand a child illness

Certain regulatory genes in the placenta may be linked to the varying severity of febrile seizures during fever episodes in babies and toddlers, a new study co-led by UdeM’s Sarah Lippé suggests.

For the first time, a Quebec research team is studying the expression of three families of genes in the placenta and the incidence of febrile seizures in children.

Led by Université de Montréal psychology professor Sarah Lippé and Institut national de la recherche scientifique (INRS) professor Cathy Vaillancourt, the study was published in mid-September in the Journal of Neuroendocrinology.

Febrile seizures, or convulsions associated with fever episodes, affect 2 to 5 per cent of children from birth through the age of 5. Under certain conditions, these children are at risk of presenting cognitive difficulties as they develop.

As part of a doctoral project by Fanny Thébault-Dagher, who was assisted by postdoctoral fellow Morgane Robles for placental analyses, the researchers looked at three families of genes expressed in the placenta.

During pregnancy, the serotonin and stress hormone systems play a role in the development of the unborn baby’s brain. Vascular regulators are linked to oxygen and nutrient transport.

The researchers are trying to find a link in humans between the mother, the placenta, and the baby, which they have found is a difficult triad to study.

"We first studied these regulators in the placenta," said Vaillancourt. "So it’s important to systematically observe the placenta after pregnancy, whether normal or abnormal, since there may be predictive factors."

Maternal stress linked to changes

In a previous study , Vaillancourt observed that maternal stress was linked to changes in the expression of certain systems in the placenta. Lippé found that prenatal stress reported by the mother predicted an earlier age of seizure onset.

In animals, maternal stress during pregnancy may play a role in the severity of seizures after birth. "It is still difficult to make this connection in humans," said Lippé. "It’s important to understand the mechanisms during pregnancy, since they may be associated with seizures after birth."

The team would like to do further research to validate their results on a larger cohort.

"Neurodevelopment begins the first day after conception," said Lippé, "so it’s essential that we understand the stages of growth that can lead to postnatal consequences."

About this study

" Febrile seizure incidence and age at first occurrence are associated with changes in placental normalized gene expression: the ’3D’ pregnancy cohort study ," by Fanny Thébault-Dagher et al, was published on September 20, 2021, in the Journal of Neuroendocrinology. This study was made possible thanks to the 3D Study of 2,366 Quebec mother/child dyads. Financial support was provided by the Canadian Institutes of Health Research (CIHR), the Natural Sciences and Engineering Research Council of Canada (NSERC), Fonds de recherche du Québec - Nature et technologies, Fonds de recherche du Québec - Santé, and the Fonds Jean-Pierre Hogue.

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