Relationship Between Brain Tissue Volume and Gestational Age: Panel A on the left shows the relationship between gestational age (X axis) and volume of the cortex (Y axis), separated by sex. For males, the higher the gestational age, the higher the cortex volume at 12 months (corrected) age. Panel B on the right shows the relationship between white matter volume and gestational age. Higher gestational age predicts greater white matter in females, but low volumes in males. This effect for both sexes was not statistically significant for either group, though the interaction is.