Positional cranial deformation and domain-specific neurodevelopment in small-for-gestational-age infants: a cross-sectional study

Background Infants born small for gestational age (SGA) face a higher likelihood of divergent neurodevelopmental trajectories. Positional cranial deformation is an early and observable clinical feature that has been associated with developmental differences in general populations, but its neurodevelopmental relevance in SGA infants remains unclear. This study investigated the associations between positional cranial deformation and domain-specific neurodevelopmental performance among SGA infants. Methods This cross-sectional analysis was conducted within a clinical follow-up cohort of SGA infants. A total of 156 infants who completed both three-dimensional cranial morphology assessment and Gesell Developmental Schedules (GDS) evaluation were included; the upper eligibility limit was 18 months of age. Assessments were concentrated in early infancy, with median ages of 6.36 months (IQR, 4.80–9.18) at cranial scanning and 6.90 months (IQR, 6.12–10.08) at GDS assessment. Multiple linear regression models examined the associations between cranial shape and developmental quotient (DQ) scores. Results Overall cranial deformation was associated with lower developmental quotient scores in the fine motor and adaptive behavior domains after false discovery rate correction ( P FDR < 0.05). Exploratory subtype analyses suggested similar patterns for brachycephaly and plagiocephaly, particularly in fine motor and adaptive behavior domains. The direction and magnitude of associations were generally consistent in sensitivity analyses. Conclusion Cranial deformation in SGA infants was associated with differences in developmental performance in fine motor and adaptive behavior domains. Exploratory subtype analyses suggested nominal associations for brachycephaly and plagiocephaly, but these associations were no longer significant after multiple-comparison correction. These findings suggest that cranial morphology may provide an accessible clinical indicator for developmental monitoring during SGA follow-up.