AIMS: This study aimed to (1) evaluate associations between Early and Term structural MRI (sMRI) brain abnormality scores and adverse motor outcomes at 6-years corrected age (CA), (2) determine their diagnostic accuracy in predicting adverse motor outcomes and cerebral palsy (CP) at 6-years CA. METHODS: Infants born <
31-weeks gestational age (GA) returning for 6-year follow-up were included. Early and Term sMRI were scored using a validated method, deriving white matter, cortical grey matter, deep grey matter, cerebellar and global brain abnormality scores (GBAS). At 6-years CA, Movement Assessment Battery for Children-2nd Edition (MABC-2) was administered. Linear regression assessed associations between Early and Term GBAS/subscale scores and 6-year MABC-2 total score. For diagnostic accuracy, sMRI scores were categorised as none/mild vs moderate/severe, MABC-2 cut-off ≤ 5th percentile, and CP as present/absent. RESULTS: Infants had Early MRI (n = 123) at mean PMA 32.5-weeks (median GA 28.4-weeks
mean birthweight 1101 g) and n = 114 had Term MRI (Mean PMA 40.8-weeks). Nine had CP and n = 116 had MABC-2 scores. Early (B: -1.92
p ≤ 0.001) and Term (B: -1.67
p ≤ 0.01) GBAS were negatively associated with MABC-2 scores. Both Early and Term GBAS had high specificity (Sp) and low sensitivity (Se) in predicting MABC-2 ≤ 5th percentile (Early: Se 36 %, Sp 82 %
Term: Se 28 %, Sp 93 %) and predicted CP with high Se and Sp (Early: Se 78 %, Sp 78 %
Term: Se 75 %, Sp 89 %). CONCLUSION: High Sp of Early and Term MRI predicting an outcome on MABC-2 may help accurately identify infants unlikely to develop motor impairments at 6-years CA.