Pandemic-induced distress in pregnancy alters fetal brain development

Compared with infants born before the COVID-19 pandemic, those born during the pandemic had decreased fetal brain development, which researchers found was linked to higher levels of distress in women giving birth during the pandemic.

“Understanding how contemporary stressors may influence fetal brain development during pregnancy has major implications for basic science and informing public policy initiatives,” senior study author Catherine Limperopoulos, PhD, chief and director of the Developing Brain Institute at Children’s National Hospital and a professor of pediatrics and radiology at George Washington University in Washington, D.C., said in a press release. “With this work, we are able to show there’s a problem, it’s happening prenatally, and we can use this model to start exploring how we can reduce stress in moms and support unborn babies.”

Study enrollment

Limperopoulos and colleagues compared maternal distress levels in 137 pregnant women enrolled between March 2014 and February 2020 and 65 pregnant women without COVID-19 exposure enrolled between June 2020 and April 2021. They also compared fetal brain volume and cortical folding using 182 and 92 fetal MRI scans available for the pre-pandemic and pandemic cohorts, respectively.

At presentation for the fetal MRI, the researchers administered four questionnaires to assess maternal distress — specifically examining state anxiety, trait anxiety, stress and depression. Their analysis included measures from 173 women who provided responses.

Maternal distress

Among pregnant women who responded to the questionnaires, 34 (27.6%) in the pre-pandemic cohort and 26 (52%) in the pandemic cohort had elevated distress indicated in at least one of the questionnaires. Women in the pandemic cohort also had significantly higher levels of depression (beta coefficient = 1.7; 95% CI, 0.5-2.9) and stress (beta coefficient = 3.92; 95% CI, 2.03-5.81) compared with those in the pre-pandemic cohort.

MRI findings

MRI scans revealed that the pandemic cohort had smaller volumes of fetal white matter (least squares mean, 93.3 cm³ vs. 99.1 cm³; P < .01), hippocampus (least squares mean, 8.2 cm³ vs. 8.7 cm³; P = .01) and cerebellum (least squares mean, 1 cm³ vs. 1.1 cm³; P < .01) compared with the pre-pandemic group.

Volumes of white matter, hippocampus and cerebellum remained smaller in the pandemic cohort when adjusting for maternal distress.

Additionally, the cortical surface area of all four lobes was significantly smaller in the pandemic group compared with the pre-pandemic cohort. Local gyrification indices of all four lobes were also significantly smaller in the pandemic cohort, indicating less cortical folding.

The pandemic cohort also had significantly lower sulcal depths in the frontal, parietal and occipital lobes compared with the pre-pandemic cohort.

Elevated anxiety and stress were associated with smaller hippocampal and cerebellar volumes, and higher trait anxiety specifically was associated with lower white matter volume. However, elevated anxiety and depression were associated with greater sulcal depth.

“As we continue to elucidate the mechanisms underpinning these differences, concurrent efforts should emphasize the implementation of intervention programs for both maternal-infant dyads,” Limperopoulos and colleagues wrote.

Moving forward, research should examine — and already has begun examining — the long-term impacts of the pandemic on “the COVID generation of infants,” the researchers wrote.

Reference:

• Pandemic-related stressors in pregnant women may impact their babies before they’re born. https://e3.eurekalert.org/news-releases/953326. Published May 26, 2022. Accessed May 31, 2022.