Smell and Taste to Improve Nutrition in Very Preterm Infants: A Randomized Controlled Pilot Trial

The perception of smell and taste, though present early in development, is not routinely considered in the care of preterm infants. Smell and taste are known to increase gut motility, insulin secretion, and the release of appetite, digestive and metabolic hormones.

We aimed to investigate the effect of regular smell and taste on the time from birth to full enteral feeds, and the feasibility of the study protocol in very preterm infants.

In a randomized controlled trial, infants <29 weeks' postmenstrual age (PA) were assigned to receive either the smell and taste of milk before each feed or to have no exposure to the smell and taste of milk (control).

Infants in the treatment group (n = 28) and control group (n = 23) were born at a mean (SD) PA of 26.7 (1.5) and 27.2 (1.4) weeks, respectively. They reached full enteral feeds at a median (IQR) of 13.5 (10.0-19.0) and 15.5 (11.0-22.0) days, respectively. Survival analysis showed an adjusted hazard ratio of 1.63 (95% confidence interval 0.91-2.91; p = 0.10) for the effect on the time to establish full enteral feeds. Repeated-measures analysis indicated significant group differences in weight z scores at 36 weeks' PA and at discharge in favor of the intervention (p < 0.05).

These data indicate that the smell and taste of milk may improve milk tolerance and weight in preterm infants. The role of regular smell and taste in promoting enteral nutrition and growth in preterm infants merits a larger trial powered to detect important outcomes.