The hidden pandemic: COVID-19-related stress, SLC6A4 methylation, and infants' temperament at 3 months

The COVID‐19 pandemic represents a collective trauma that may have enduring stress effects during sensitive periods, such as pregnancy. Prenatal stress may result in epigenetic signatures of stress‐related genes (e.g., the serotonin transporter gene, SLC6A4) that may in turn influence infants’ behavioral development. In April 2020, we launched a longitudinal cohort study to assess the behavioral and epigenetic vestiges of COVID‐19‐related prenatal stress exposure in mothers and infants. COVID‐19‐related prenatal stress was retrospectively assessed at birth. SLC6A4 methylation was assessed in thirteen CpG sites in mothers and infants’ buccal cells. Infants’ temperament was assessed at 3‐month‐age. Complete data were available from 108 mother‐infant dyads. Greater COVID‐19‐related prenatal stress was significantly associated with higher infants’ SLC6A4 methylation in seven CpG sites. SLC6A4 methylation at these sites predicted infants’ temperament at 3 months.