Longitudinal study of sleep behavior and motor development in low-birth-weight preterm children from infancy to preschool years.

objectiveTo verify the relationship between sleep characteristics and motor development in low-birth-weight preterm infants during infancy and preschool years.

methodForty-one healthy preterm infants (<37 weeks' gestation) with low birth weight (≤1500 g) were assessed longitudinally at three different time points: at 6 months of corrected age, at 12 months of corrected age, and at 4-5 years of chronological age. At 6 and 12 months, motor development was assessed using the Denver Developmental Screening Test II and Alberta Infant Motor Scale, while sleep-related habits and disturbances were assessed using the Brief Infant Sleep Questionnaire. At 4-5 years, motor development was reassessed using the Pediatric Evaluation of Disability Inventory and sleep was reassessed using the Sleep Disturbance Scale for Children. Correlations were performed using sleep quality as the predictor variable and motor development as the outcome variable.

resultsMost infants had suspected delay/atypical development at 6 and 12 months, with no difference between the scales (p = 1.000). Suspected delay/atypical development were associated with lateral sleep position (p = 0.004), greater number of nighttime awakenings (p = 0.008), and longer awake periods (p = 0.014) only at 6 months. At 4-5 years, the suspected delay/atypical development observed at 6 and 12 months disappeared.

conclusionsSleep quality correlated with delayed/atypical motor development in healthy preterm infants with low birth weight only at 6 months of corrected age, which did not appear to affect later development of motor skills.