Objective: To evaluate whether prolonged exposure of preterm infants to their mother`s odor (breast milk) leads to decreased stress parameters.
Methods: Fifteen clinically stable preterm infants were included. The study design consisted of two days of pre-intervention, followed by two days of intervention using a cotton pad soaked with 1.5 ml of breast milk that was placed in the incubator about 10 cm from the infant`s head to provide continuous maternal breast milk odor, ending with two days of post-intervention. Physiologic parameters including heart rate and respiratory rate were recorded, as was salivary cortisol.
Results: The respiratory rates did not change, and the heart rate showed minute, un-meaningful sporadic changes. The saliva cortisol showed meaningful changes in the hypothesized direction. The levels were 11.38±5.03, 9.51±4.38 and 4.99±3.42 nmol/L during the pre-intervention, intervention and post-intervention stages, respectively. The overall repeated univariate analysis of the cortisol measure showed significant differences (F=9.34;df=2,28, p
Conclusions: By creating a method to expose the infant to continuous maternal breast milk odor without the mother`s presence, we were able to study the effect of milk odor on the reduction of stress parameters. The results of the decreased cortisol levels indicate that maternal breast milk odor has a soothing effect on preterm infants. The variability of the soothing response indicates the need for further studies to evaluate this simple, non-harmful, inexpensive and safe method of soothing for clinical use.
