The association between prenatal maternal anxiety, infant brain volumes, and temperament during the COVID-19 pandemic.

Prenatal maternal stress (PNMS), anxiety, and depression are associated with altered trajectories of infant socio-emotional and brain development, including the amygdala and prefrontal cortex (PFC). During the COVID-19 pandemic, prenatal anxiety and depression was significantly elevated, yet the impact on infant neurodevelopment remains uncertain. The objective of this study was to determine whether PNMS and mental health during the pandemic was associated with infant amygdala and PFC volumes as well as temperament. Participants were enrolled in the Canadian 'Pregnancy during the COVID-19 Pandemic' cohort study. Pregnant individuals had their perceived stress, pandemic-related objective hardship, and mental health measured via questionnaires. Infant magnetic resonance imaging (MRI) scans (n = 100) were conducted at 3 months of age, and parents reported on infant temperament at 6 months of age. General linear models were used to examine the associations among PNMS, mental health, brain volumes, and developmental outcomes. Prenatal maternal anxiety negatively predicted 3-month left infant amygdala volumes (B = -5.919; p = 0.016; 95% CI, -10.748 to -1.089). Smaller left amygdala volumes were associated with greater infant 6-month negative affectivity (B = -0.003; p = 0.002; 95% CI, -0.006--0.001). This study provides evidence for infant brain alterations related to prenatal maternal anxiety, indicating that the impact of anxiety on infant development during the COVID-19 pandemic may have long-lasting implications for children's health. Our findings suggest that prenatal anxiety may be a key area for screening and intervention during pregnancy to best support healthy infant development.