Discrimination of taste and preference for sweet in premature babies

A modified method for registering non-nutritive sucking behaviour with and without taste stimulation enabled us to study taste perception of premature babies. We wanted to study how babies who had no extrauterine taste experience reacted to one or more stimuli with water and 33% glucose. Eight randomly selected healthy newborns (three of them being SGA without further symptoms), exclusively fed by gastric tube, were studied. The mean gestational age at the time of the study was 35.5 weeks. They were studied five times with water and five times with glucose just before feeding. In seven babies the sucking response to glucose was greater than that to water from the first trial onwards. Sucking response increased with repeated glucose stimulation, but remained the same with water stimulation. The eighth baby behaved completely differently. We concluded from our results that premature babies with a postconceptional age of 35 weeks can discriminate between sweet and not-sweet. The greater sucking response to glucose than to water at the first trial implies a genetic factor in the preference for sweet in humans.