COVID-19: Pandemic distress during pregnancy may affect foetal brain development - study

Pregnant woman cradling her belly
Pandemic distress may affect foetal brain development, small study finds. Photo credit: Getty Images

Poor mental health and psychological distress experienced by pregnant women during the COVID-19 pandemic may be associated with changes in the brain of developing foetuses, according to new research.

Researchers from the Children's National Hospital at George Washington University and the MedStar Washington Hospital Center in Washington DC, US, conducted a small international study of 202 women who didn't contract COVID-19. The research found that mums-to-be were dealing with greater levels of stress and depression during the pandemic than the pregnant women studied prior. 

As part of the study - which was published in Communications Medicine - MRI scans were taken of foetuses in the latter half of pregnancy. In foetuses with distressed mothers, the researchers found some areas of the brain were smaller and brain development had been delayed.

While the authors say further research is required, the study suggests psychological distress experienced by pregnant women during the pandemic may be associated with altered foetal brain development.

The study involved 65 women who were pregnant during the height of the pandemic between June 2020 to April 2021. The 137 others had been pregnant prior to the pandemic, between March 2014 to February 2020. None of the participants assessed during the course of the pandemic were known to have been infected with SARS-CoV-2, the virus that causes COVID-19.

The study assessed the potential impact of the pandemic itself on pregnant women and their developing foetuses before birth, rather than the impact of contracting the virus.

Catherine Limperopoulos and her colleagues imaged the brains of foetuses in the wombs of mothers who were pregnant before and during the pandemic using MRI. The imaging assessed the surface structure of the brain, including cortical folding, the wrinkled shape - gyrification - and the depth of the wrinkles of the brain's surface.

Of the 202 participants, the authors asked 173 mothers a series of questions to investigate any distress experienced during pregnancy, including anxiety, stress and depression. The authors found stress and depression were reported proportionally more in the mothers who were pregnant during the pandemic. Overall, 27.6 percent of women in the pre-pandemic cohort and 52 percent of women in the pandemic cohort were considered to have high levels of psychological distress, although anxiety remained consistent across the groups.

The authors observed that three brain structure and volumetric measures - foetal white matter of the cerebrum, hippocampal and cerebellar volumes - were decreased in the foetuses from the pandemic cohort, compared to those in the pre-pandemic cohort. Development in these brain structures was negatively associated with anxiety, stress and depression scores. 

The authors observed that the foetuses of pregnant women who had reported low stress in the analysis also had lower volumes across the three brain measures in the pandemic cohort, compared to the pre-pandemic cohort. The authors suggest this variability and inconsistency indicates multiple factors are involved in foetal brain development.

When observing the foetuses' brain structure, the authors found the cortical surface area and local gyrification index were decreased in all four lobes, while sulcal depth was lower in the left frontal, parietal and occipital lobes in the pandemic cohort, with the metrics possibly indicating delayed brain gyrification or development.

The authors warn that the differences when comparing multiple findings suggest there are many factors that influence brain development - not just elevated maternal stress.

"The variability of data suggests there are periods of plasticity that could allow for interventions for mother and child. The authors did not investigate the long-term impact of the potential changes shown in this study and they suggest future research could investigate this further," the researchers said.