General movements assessment and neonatal risk burden in relation to 24-month gross motor outcomes in high-risk infants: a longitudinal observational study

Early identification of high-risk infants for adverse motor outcomes is essential for timely intervention. This study aimed to compare neonatal clinical characteristics, neurological findings, and qualitative and quantitative spontaneous movement measures between infants with no or mild gross motor limitation and those with clinically significant gross motor limitation at 24 months corrected age, and to examine the associations of these early measures with continuous GMFM-88 outcomes. This longitudinal observational study included 53 high-risk infants consecutively recruited between May 2023 and May 2024 and followed through May 2026. Neonatal clinical characteristics, including gestational age, birth weight, and major morbidities, were recorded. At term-equivalent age, infants underwent HNNE, General Movements Assessment (GMA), GMOS-R score and percentile evaluation. At 3–5 months corrected age, fidgety movements and MOS-R were assessed. Motor outcomes at 24 months corrected age were evaluated using GMFM-88 and gross motor outcome group. Sixteen infants (30.2%) were classified as clinically significant gross motor limitation. These infants were characterized by a higher neonatal risk burden, including lower gestational age (p = .012), lower birth weight (p < .001), longer NICU stay (p < .001), and increased incidence of major morbidities. They also demonstrated lower HNNE, GMOS-R, GMOS-R percentile rank, MOS-R, and GMFM-88 total scores (all p < .001). GMOS-R percentile rank showed the strongest correlation with GMFM-88 total score (rho = 0.931, p < .001), followed by MOS-R (rho = 0.854, p < .001) and GMOS-R score (rho = 0.827, p < .001). In adjusted linear regression analyses, GMOS-R percentile rank and MOS-R score remained significantly associated with 24-month GMFM-88 total score after adjustment for gestational age or birth weight. Absent fidgety movements and cramped-synchronized term GMs patterns were associated with poorer outcomes (p < .001). Notably, infants with both elevated neonatal risk burden and abnormal movement patterns exhibited the most unfavorable developmental trajectories. Early neurological findings, spontaneous movement quality, and neonatal risk burden were closely associated with 24-month gross motor function. Integrating HNNE, GMA, GMOS-R/GMOS-R percentile rank, and MOS-R into structured follow-up programs may support early risk stratification and developmental surveillance in high-risk infants.