According to a new study from the Medical University of Vienna, viral infections during pregnancy have an impact on the mother's brain and postpartum behaviour.

The findings of the research were published in the journal 'Molecular Psychiatry'. There is ample data from studies in mouse models demonstrating that viral infections during pregnancy can affect the developing brain of the young in utero (in the womb) with lifelong consequences for brain function and behaviour.

A preclinical study has now shown, for the first time, that a viral-like immune activation during pregnancy also affects the maternal brain and significantly disrupts maternal care behaviour after birth.

These results are published by a research group led by behavioural biologist Daniela D Pollak from the Division of Neurophysiology and Pharmacology at MedUni Vienna's Center for Physiology and Pharmacology, working together with colleagues from the Division of Molecular Neurosciences at MedUni Vienna's Center for Brain Research and from Columbia University (USA).

In this preclinical study, the researchers used a chemical substance that activates the same receptor pathways as viruses, to trigger the immune system of the mother during pregnancy in a manner that is comparable to the typical course of a viral infection. Once the young had been born, the maternal care behaviour of the dams was behaviourally tested.

"Dams who had experienced a viral-like immune activation were less caring towards their young than animals in the control group," said Daniela D Pollak, describing the results.

"The naturally strong drive to take care of one's own offspring and to keep them safe from harm was much less pronounced corresponding to a significant decline in attachment behaviour."

The researchers not only observed changes in the behaviour of the dams but also identified structural, molecular and functional changes in their brains and were able to discover some of the underlying mechanisms.

Even though animal-model results cannot be directly translated to humans, the study team said it is an indication that viral infections during pregnancy can change mothers' behaviour toward their babies. "Women who have had systemic viral illnesses during pregnancy may be at increased risk of impaired mother-infant bonding," Pollak explained.

The researcher hoped that this will raise awareness so that women with a history of infection during pregnancy may be more prompted to seek medical or psychotherapeutic treatment if they experience indications of impaired bonding after birth, which may affect the well-being of the mother and child.