Orbito-frontal cortex functional connectivity mediates the relationship between fetal growth and childhood impulsivity

The prenatal period is critical for a healthy development, and exposure to adversity during it may provoke alterations of several biological tissues and systems, resulting in health outcomes that may take place into childhood and adulthood. The orbito-frontal cortex (OFC), central in cognitive processes, is sensitive to negative environmental effects in the intrauterine environment. We investigated the association between OFC function and decision-making behavior in response to a poor-quality prenatal environment. We evaluated a subsample of the MAVAN longitudinal Canadian birth cohort gathering data on anthropometric measurements at birth, and resting-state functional MRI (rsfMRI) and decision-making (using the Information Sampling Task from the CANTAB battery) measured later in life. We performed a mediation analysis to investigate the direct and indirect effect of being born small for gestational age (SGA) on the Information Sampling Task performance, through OFC-related functional connectivity. Being born SGA is associated with decreased functional connectivity between the left hemisphere OFC and the middle frontal gyrus (OFC-MFG). Additionally, increased OFC-MFG connectivity is linked to better IST performance. Thus, SGA individuals have an altered OFC- MFG functional connectivity, which impacts on their performance on a decision-making task. Lower OFC-MFG functional connectivity and impulsive decision-making were associated to the SGA condition, reflecting a poor-quality prenatal environment. These findings highlight the importance of the prenatal period for a healthy development and suggest that neuroimaging focusing on the affected areas may identify individuals at higher risk of developing psychopathologies, and direct for proper interventions.