Fetal sensory competencies.

A growing body of evidence is available about the functioning of fetal sensory systems during gestation. This article aims at reviewing data concerning (i) the presence of potential sensory stimulation in the fetal milieu, (ii) the sequential functional development of the sensory systems and (iii) physiological and behavioral responses of fetuses to various types of stimulation. Human data are compared with data collected in other mammalian species. Most studies have investigated auditory and chemosensory (olfactory and gustatory) responsiveness of the fetus in the second half of gestation. They demonstrate that (i) motor and heart rate responsiveness depends on gestational age and characteristics of stimulation; (ii) fetal sensory experience has short- and long-term effects at morphological, functional and behavioral levels (for example transnatal learning). The clinical consequences of the fetal sensory functioning are developed.