preterm infant

stress-coping

neonatal intensive care unit

The purposes of the present study were to clarify the characteristics of responses to environmental stimuli andstress-coping behaviors exhibited by preterm infants between 33 and 35 weeks' post-conceptual age, and considerappropriate care for preterm infants that is based on their post-birth developmental stage. A total of 6 preterm infants,between 25 and 32 weeks' gestational age at birth and free of known developmental risk factors, were studied in theneonatal intensive care units at 2 general hospitals in Japan. The infants were observed and video-recorded from 33 to35 weeks' gestational age. Data were analyzed using quantitative and qualitative methods. The following results wereobtained.1. Between 33 and 35 weeks' post-conceptual age, various coping behaviors exhibited by preterm infants tendedto appear sporadically and tended to be accompanied by over straining.2. In situations in which an infant's arms are not close to his/her mouth, the natural posture for an infant, copingbehaviors using the hands or arms tend to decrease.3. Infants tend to have an unstable posture following over strained leg movements.4. Defensive coping responses, such a‘s weakened muscle tone' and‘ rapid sleep state decline', tend to occurfollowing over strained movements.5. In environments with high-pitched noise and in infants with an earlier gestational age at birth, defensivecoping responses tend to linger. Consequently, infants show a stressful sleep state( state 1-2A).These findings indicate that when caring for preterm infants between 33 and 35 weeks' post-conceptual age, it isnecessary to keep them in a stable position, especially their leg; avoid restricting their hand and arm movements; andregulate the neonatal intensive care unit based on appropriate evaluations.