Functional analysis of spontaneous movements in preterm infants

Spontaneous movements of premature infants between 25 and 34 weeks conceptional age were observed for 1 hr on two or three occasions. Subjects had low-risk prognoses and were clinically stable at the time of testing. Behavioral acts were scored using a 0/1 time sampling technique in 60 continuous, 1-min time blocks. Temporal associations between individual movements were found using chi-square analyses. Some associated behaviors contained combinations consistent with neonatal action patterns, for example, single and bilateral leg kicking, head turning, and mouthing. Features of state organization were also evident in that general motor activity (GM), which has been used as a marker of active sleep (AS) in neonates, was found to cluster temporally with startle, facial, and head movements but not eye movements. Behavioral quiescence (> or = 5 s) was dissociated from AS-related behaviors (GM, facial, head, and eye movements). Combinations of state-segregated behaviors were more likely to exhibit co-occurrence within 1-min intervals in infants 30 weeks conceptional age and older.