Impact of kangaroo care on circadian rhythm, growth, physiological stability in premature infants, and cortisol and melatonin levels in maternal breast milk: A randomized controlled trial.

PURPOSE: This study aimed to examine the effects of regular kangaroo care (KC) on sleep-wake cycles, growth, physiological stability, and maternal breast milk cortisol and melatonin levels in premature infants.

DESIGN

This study was a parallel group, single-blind, pre-test-post-test, randomised controlled trial (RCT).

METHODS

This randomized controlled study was conducted in a neonatal intensive care unit (NICU) in Türkiye between September 2024 and September 2025 Thirty-six premature infants were randomized to intervention (n = 28) or control (n = 28). Infants in the intervention group received KC for three consecutive days, twice daily (10:00 a.m. and 10:00 p.m.) for 60 min per session. Data were collected using the Infant Information Form, Physiological Parameters Monitoring Chart, and Premature Infant Sleep-Wake Cycles Tracking Chart. Sleep-wake cycles were monitored using a Bispectral Index device. Breast milk cortisol and melatonin levels were measured at baseline and on day three using the competitive ELISA method. The study was registered at ClinicalTrials.gov (NCT06589349).

RESULTS

Regular KC had a statistically significant effect on BIS values, heart rate, respiratory rate, oxygen saturation, and body temperature (p < 0.05). No statistically significant effects were observed on infant body weight or on maternal breast milk cortisol and melatonin levels (p > 0.05).

CONCLUSION

The findings indicate that regular KC is associated with improved regulation of the sleep-wake cycle and enhanced physiological stability in premature infants. No significant changes were observed in maternal breast milk cortisol or melatonin levels following KC.