Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Master of Arts

Program

Education

Supervisor

Emma G. Duerden

Abstract

Prenatal maternal stress (PNMS) is associated with altered trajectories of infant socio-emotional and brain development, including brain structures such as the amygdala and prefrontal cortex (PFC). During the COVID-19 pandemic, which was a major global stressor, PNMS was significantly elevated, yet the impact on infant neurodevelopment remains uncertain. The objective of the present study was to determine whether PNMS during the pandemic was associated with infant amygdala and PFC volumes as well as temperament. In addition, we examined whether social support and resilience during pregnancy were protective factors.

Participants were enrolled in the Canadian ‘Pregnancy during the COVID-19 Pandemic’ cohort study. Pregnant individuals had their perceived stress, pandemic-related objective hardship, mental health, social support, and resilience measured. 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, brain volumes, and developmental outcomes and to assess the role of protective factors.

The results found that prenatal maternal anxiety negatively predicted 3-month left infant amygdala volumes. Smaller left amygdala volumes were also associated with greater infant 6-month negative affectivity. Maternal stress was associated with smaller infant PFC volumes, and this relationship was moderated by social support and resilience. This study provides evidence for infant brain alterations related to prenatal maternal perceived stress and anxiety, indicating that the impact of PNMS on infant development during the COVID-19 pandemic may have long-lasting implications for children’s health. Our findings suggest that social support, resilience, and mental health may be key areas for screening and intervention during pregnancy to best support healthy infant development.

Summary for Lay Audience

Stress during pregnancy has been related to differences in children’s brain, behavior, and emotions. Prenatal stress can increase a stress hormone called cortisol, which can negatively impact brain development in the fetus. Differences in brain development during pregnancy can impact children long-term. Given that anxiety and depression was at high levels during the COVID-19 pandemic, it is important to understand the impact of prenatal maternal stress on their children. Our study looked at the relationship between stress during pregnancy and two important brain regions for emotions: the amygdala and prefrontal cortex. We also looked at whether differences in brain volumes were related to infant temperament (i.e., innate emotional regulation style) at 6-months. Finally, we also studied whether partner support and resilience (i.e., ability to adapt/bounce back after a stressful event) lessened the link between prenatal stress and infant brain development. Our participants were a part of the Canadian ‘Pregnancy during the COVID-19 Pandemic’ (PdP) study. Questionnaires were used to assess individuals on their mental health, social support from their partner, resilience, and infant temperament at 6-months. Magnetic resonance imaging (MRI) was used to scan 100 3-month-old infants. Our findings showed that higher levels of anxiety during pregnancy was related to smaller amygdala volumes when infants were 3-months old. More negative infant temperament was also linked to smaller amygdala volumes. Social support and resilience lessened the relationship between maternal perceived stress and infant prefrontal cortex volumes. Our results suggest that prenatal stress during the pandemic could have long-lasting implications for children’s health and brain development, and that partner support and resilience could have a protective effect.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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