Manual and automated assessments of general movements in neonates are associated with early autism risk at 18 months

General movements (GMs) refer to infants’ spontaneous motor activities before the emergence of voluntary motor activity. Abnormal GMs in neonates have been regarded as a marker of poor neurodevelopmental outcomes, with preliminary findings in autism. To examine the relation between abnormal GMs in neonates and autism risk, videos of neonates (n = 76) extracted from a Japanese birth cohort were retrospectively exploited. A manual assessment of GMs was completed using the General Movement Assessment Optimality Score (GMOS-R) rated by professionals blinded from all clinical information. An automated assessment of several features of neonates’ motor activity was also conducted using videos of neonates. Outcome measures were the M-CHAT score at 18 months to document autistic risk status and the Strengths and Difficulties Questionnaire (SDQ) at four years to measure non-autistic general psychopathology. The GMOS-R total score and subscores significantly predicted the autistic risk status according to M-CHAT, but not any SDQ scales or the Total Difficulties score. In the manual assessment of GM, “Global poorness of motion” was the most informative feature in predicting ASD risk. The classification performance systematically increased with the addition of automatically extracted features, as indicated by the Loglikelihood tests. In contrast, the DeLong tests for comparison of AUC failed to reach statistical significance. Such improvement came mainly from incorporating information about the imbalance in motion strength between the upper and lower limbs, and was more marked for awake babies. This finding confirms the relevance of considering abnormal motor patterns in neonates as an early marker of autistic risk.