Summary of z-scores and z-score slopes of preterm infants.

<p>The z-scores measure whether the average metabolite levels in term versus preterm infants were significantly different. The z-score <i>slopes</i> measure whether an increase (or decrease) of a metabolite concentration in the premature cohort over time was significantly different from what was observed in the term-born infants. E.g., the significantly negative z-score <i>slope</i> for NAA in parietal WM indicates that NAA increased slower with age in the premature group. Values for mIns, glutamate, and taurine were all not significantly different from zero and are not listed.</p><p>p<0.05, **p<0.01, ***p<0.001.