Associations between oxidative stress biomarkers during pregnancy and infant cognition at 7.5 months

Oxidative stress has been identified as an important biological pathway leading to neurodevelopmental delay. However, studies assessing the effects of oxidative stress on cognitive outcomes during infancy, a critical period of neurodevelopment, are limited. Our analysis included a subset of those enrolled in the Illinois Kids Development Study (N = 144). Four oxidative stress biomarkers (8-isoprostane-PGF2 alpha, 2,3-dinor-5,6-dihydro-8-iso-PGF2 alpha, 2,3-dinor-8-iso-PGF2 alpha, and prostaglandin-F2 alpha) were measured in second and third trimesters urine and were averaged. Infant cognition was measured using a visual recognition memory task consisting of five blocks, each with one familiarization trial (two identical stimuli) and two test trials (one familiar and one novel stimulus). Outcomes measured included average run duration (a measure of information processing speed), novelty preference (a measure of recognition memory), time to reach familiarization, and shift rate (measures of attention). Linear regression was used to estimate associations between individual oxidative stress biomarkers and each outcome. Increasing 8-isoprostane-PGF2 alpha, 2,3-dinor-8-iso-PGF2 alpha, and prostaglandin-F2 alpha were associated with a decrease in novelty preference (beta = -0.02, 95% confidence interval [CI] = -0.03, 0.00; beta = -0.02, 95% CI = -0.04, 0.00; beta = -0.01, 95% CI = -0.02, 0.00, respectively), as well as a modest increase in shift rate. These findings suggest that oxidative stress may be associated with poorer recognition memory in early infancy.