This study was conducted to evaluate the effect of breast milk olfactory stimulation on physiological responses, oral feeding progression, and body weight in preterm infants.

A repeated measures design with nonequivalent control group was used. The participants were healthy, preterm infants born at a gestational age of 28~32 weeks; 12 in the experimental group and 16 in the control group. Data were collected prospectively in the experimental group, and retrospectively in the control group, by the same methods. Breast milk olfactory stimulation was provided 12 times over 15 days. The data were analyzed using the chi-square test, Mann-Whitney U test, Wilcoxon signed rank test and linear mixed models using SPSS 19.

The gastric residual volume (GRV) of the experimental group was significantly less than that of the control group. The heart rate, oxygen saturation, respiration rate, transition time to oral feeding, and body weight were not significantly different between the two groups.

These findings indicate that breast milk olfactory stimulation reduces GRV and improves digestive function in preterm infants without inducing distress.