Effects of Bundled Supportive Interventions on Preterm Infants' Stress-Related Outcomes During Invasive Procedures

The proposed 2-year study has two specific aims: (1) to examine the effects of a "bundle" of supportive interventions on preterm infants' stress (salivary cortisol and dehydroepiandrosterone \[DHEA\] levels and physiological signals of infant distress), sleep, and physical activity in the NICU, and (2) to explore the relationships among preterm infants' salivary cortisol and DHEA levels, physiological signals of infant distress, sleep, and physical activity. This randomized controlled trial will adopt a longitudinal repeated-measures design to examine the effects of bundled supportive interventions on preterm infants' stress (salivary cortisol and DHEA levels \[using ELISA kit\] and physiological signals of infant distress \[using bedside electrocardiographic monitors\]), sleep and physical activity (using ankle actigraphy) during their NICU hospitalization. Preterm infants (N=120) meeting the study criteria will be randomly assigned to one of two conditions: (1) control condition: usual NICU care + positioning + gentle touch +routine kangaroo mother care (KMC) \ 45 minutes. Outcome variables will include infants' biological responses to stress (salivary cortisol, salivary DHEA, and physiological signals of infant distress), sleep patterns, and physical activity.