Optimal Timing to Utilize Olfactory Stimulation with Maternal Breast Milk to Improve Oral Feeding Skills in the Premature Newborn

Background: Olfactory maturation is essential for successful oral feeding. Previous studies have suggested that olfactory stimulation with maternal breast milk may expedite oral feeding skills in the premature infant; however, the optimal developmental window to utilize this intervention and sex-specific responses to stimuli are largely unknown. Objectives: To determine individual responses to olfactory stimulation with mother's own milk (MOM) on feeding outcomes in premature newborns. Materials and Methods: Infants born between 28 0/7 and 33 6/7 weeks' gestation (n = 36) were randomized to receive either MOM or water (sham) stimulus during the learning process of oral feeding. Clinical and feeding outcomes were recorded. Statistical analyses examined the effect of stimulation with MOM on feeding outcomes stratified for age and sex. Results: Overall, there was no significant difference between sham infants compared with MOM infants in mean postmenstrual age of full oral feeds (sham: 35 5/7 versus MOM 36 0/7; p = 0.37). However, when stratified by gestational age (GA), infants born <31 weeks' gestation who received MOM stimulation learned to feed sooner than controls (p = 0.06), whereas infants born >= 31 weeks' gestation learned to feed later than controls (p = 0.20) with a significant interaction (p = 0.02) between the stimulus (MOM versus sham) and dichotomized GA (<31 versus >= 31 weeks). There were no sex differences in response to olfactory stimulus. Conclusions: Infants born <31 weeks' GA who received MOM stimulation learned to feed sooner than control infants and the impact of MOM is significantly different between infants born before or after 31 weeks GA. These data suggest there may be an optimal time in development to utilize maternal breast milk to expedite oral feeding maturation in the premature newborn.