ATTRACTIVENESS OF AMNIOTIC-FLUID ODOR - EVIDENCE OF PRENATAL OLFACTORY LEARNING

Human infants art responsive to maternal odors beginning shortly after birth. In several non-human mammals, the fetus is capable of olfactor y learning and in some species neonates are attracted to the odor of a mniotic fluid (AF). The present study examined the responses of newbor n babies to AF in a biologically relevant context, i.e. during their i nitial attempt to locate the mother's nipple/areola. We observed newbo rns' spontaneous choice between a breast with the nipple/areola moiste ned with AF and an untreated breast; 23 of 30 infants chose the AF-tre ated breast. All babies had been washed before the observations, and o nly 12/30 sucked their hands/fingers prior to approaching the nipple/a reola. In a previous study with unwashed newborns, the corresponding p roportion was 27/30 (p < 0.001). We tentatively suggest that the obser ved attraction to AF odor may reflect fetal exposure to that substance (i.e. prenatal olfactory learning). Because of the salience of biolog ical odors for neonates, products that eliminate or mask such cues sho uld be avoided during the perinatal period.