Intrathalamic morphometery in infants with congenital heart disease and infants born preterm

ObjectiveTo compare intrathalamic morphometry in infants born preterm, with congenital heart disease (CHD) and typical controls and investigate associations with neurodevelopmental outcomes. Methods592 infants underwent T2-weighted brain MRI: 107 CHD [gestational age at birth (GA) [&ge;]37.00 weeks], 126 preterm (GA 23.00-36.86), 359 controls (GA [&ge;]37.00). We used data-driven structural covariance analysis to derive 8 components of coordinated expansion and contraction within the thalamus. Permutation testing was used to test associations between intrathalamic morphometry and group (control, CHD, preterm birth <32 weeks GA), GA in infants born preterm and controls, cerebral oxygen delivery (CDO2) in infants with CHD, and neurodevelopmental outcomes at 18-24 months. ResultsPreterm infants born <32 weeks GA differed from infants with CHD and controls in 6 components encompassing most of the thalamus. Infants with CHD differed from controls in 2 components containing medial, ventricle-bordering and some anterior and ventrolateral thalamic areas. GA was associated with 7 components covering most of the thalamus, excepting the left posterior thalamus. CDO2 was not associated with intrathalamic morphometry. Right posterior thalamus morphometry was associated with motor scores in preterm infants born <32 weeks, but not in controls or infants with CHD. InterpretationPreterm infants born <32.00 weeks showed widespread morphometric changes across the thalamus, with alterations in the right posterior thalamus associated with motor outcomes at 18 months. Thalamic alterations in CHD were less widespread, confined to medial, ventrolateral, and ventricle-bordering tissues, which were not related to CDO2. Together, these findings suggest distinct thalamic phenotypes in prematurity and CHD.