EMERGENCE OF STATE REGULATION IN V.L.B.W. PREMATURE INFANTS

Abstract

Behavioral observations of state were made for 24 low birthweight healthy premature infants at 32 and 36 weeks gestational age. Each observation lasted for 2-4 hours between feedings and included on a 30-second interval basis an assignment of state (quiet sleep, active sleep, drowse and alert)and a coding of related behaviors. Heart rate and respiratory pattern were also monitored mechanically. After the 32-week observation, 12 of the infants (intervention group) were transferred from the open floor intermediate special care nursery which is busy, bright and noisy, to a small nursery room where day/night cycles are maintained, noise and activity levels are significantly reduced, and nursing care is on a more individualized basis. Twelve infants (control group) remained in the open floor nursery. Developmentally expected improvements in state behavior from 32 to 36 weeks (increase in overall quiet sleep, longer mean interval of REM during active sleep, and less startle/tremor behavior) were greater for the intervention babies compared to the control group. Additionally, we are looking at each subject's change over time for specific improvements in state behavior that comprise our group comparisons and the overall coordination of these specific state behaviors for each subject to arrive at an index of state regulation at each age. This approach to data analysis may more clearly identify individual responses to environmental support or injury.