Development of the brain white matter (WM) is highly plastic, and myelination continues from the second trimester into early adulthood which predisposes the brain to effects of both adverse and supporting factors during early life. Maternal perinatal psychological distress is acknowledged as an important contributor to the offspring’s development. Furthermore, sex is known to affect the WM microstructure as well as the emergence of psychopathologies. Understanding the normal variation of microstructure in the developing brain WM is a prerequisite for recognizing alterations inflicted by early adversity that have possible long-term programming effects on behavioral and socio-emotional outcomes.

This study aimed to 1) investigate the incidence, risk factors and consequences of incidental findings in brain magnetic resonance imaging of infants; 2) optimize data acquisition parameters and pre-processing pipeline of diffusion tensor imaging (DTI) protocol applied with children; 3) describe the normal microstructural features of WM in infants and 5-year-old children; 4) investigate the associations between WM integrity and exposure to maternal perinatal psychological distress; 5) explore the associations of WM integrity and child’s emotional attention.

Vacuum assistance and vaginal birth were observed to increase the risk for subdural hemorrhages (incidence 6.9%) with no effects on early neurological development. In 5-year-olds, higher WM integrity in widespread regions was observed in girls, and we found marked asymmetry in the WM, resembling patterns previously shown in adults. Maternal perinatal psychological distress showed sexand timing-specific associations with WM integrity: prenatal symptoms predicting higher integrity in boys and postnatal symptoms lower integrity in girls. Maternal postpartum anxiety increased girls’ vigilance toward fearful faces, which was also associated with reduced WM integrity. The results imply that maternal psychological distress affects WM development with effects especially on girls. Collectively, these studies provide fundamental insight for future studies addressing the mediating mechanisms and longer-term effects between the observed associations.