Maternal stress and infant development: how prenatal programming is influenced by cortisol and physical activity

Adverse prenatal environments have been shown to increase the risk of offspring developing a range of physical and mental health issues. This study explored the effects of prenatal maternal stress and physical activity on infant cognitive development at 12 months of age. Participants included 95 mother-infant dyads; 60 percent of offspring were male. Infant cognitive development was objectively measured using the Bayley Scales of Infant and Toddler Development™, Fourth Edition (Bayley-4 ; Bayley & Aylward, 2019). Both subjective and objective measures were assessed for maternal stress (Depression, Anxiety and Stress Scales-21 and hair cortisol concentration) and physical activity (International Physical Activity Questionnaire Short Form and the 30 second sit-to-stand test). No significant correlations were found between maternal stress or physical activity and Bayley-4 cognitive scores (all p > .05), suggesting nuanced pathways that warrant further research.