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 f
etal milieu, (ii) the sequential functional develop ment of the sensor
y systems and (iii) physiological and behavioral responses of fetuses
to various types of stimulation. Human data are compared with data col
lected in other mammalian species. Most studies have investigated audi
tory 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 characte
ristics of stimulation; (ii) fetal sensory experience has short- and l
ong-term effects at morphological, functional and behavioral levels (f
or example transnatal learning). The clinical consequences of the feta
l sensory functioning are developed.