Associations of prenatal maternal stress with measures of cognition in 7.5-month-old infants

Studies have shown that prenatal stress can negatively impact neurodevelopment, but little is known about its effect on early cognitive development. We assessed the impact of prenatal stress on cognition in 152 7.5-month-old infants using Cohen's Perceived Stress Scale (PSS), maternal telomere length (MTL), and a Stressful Life Events (SLE) Scale. A visual recognition memory task consisting of nine blocks, each with one familiarization trial (two identical stimuli) followed by two test trials (one familiar stimulus, one novel), was administered. Outcomes assessed included: average time looking at stimuli (measure: processing speed), time to reach looking time criterion (measure: attention), and the proportion of time looking at the novel stimulus (measure: recognition memory). We examined the association of each stress measure with each outcome adjusted for infant age and sex, which of the two stimuli in each set was novel, household income, and maternal age, education, and IQ. Higher prenatal stress was associated with shorter looking durations [PSS (β = −1.6, 95% CI: −2.5, −0.58); SLE (β = 0.58, 95% CI: −0.08, 1.24); MTL (β = 1.81, 95% CI: 0.18, 3.44)] and longer time to reach criterion [PSS (β = 9.1, 95% CI: 1.6, 16.6); SLE (β = 12.2, 95% CI: 1.9, 24.1); MTL (β = −23.1, 95% CI: −45.3, −0.9)], suggesting that higher prenatal stress is associated with decreased visual attention in infancy.