SOOTHING EFFECT OF AMNIOTIC-FLUID SMELL IN NEWBORN-INFANTS

Newborn young of several mammalian species are attracted to the odor o f amniotic fluid (AF); these chemical cues also appear to calm neonate s and help them adapt to their novel postnatal environment. AF odor li kewise elicits positive (head orientation) responses by human infants. The present study systematically examined whether the odors of AF and mother's breasts influence the crying of the newborn infant, when sep arated from its mother. The total crying time from 31-90 min postnatal was registered on tapes in 47 healthy fullterm newborns, allocated to one of three conditions: exposure to either AF or breast odor or no e xposure (controls). Babies exposed to AF smell cried significantly les s (median 29 s) than babies in the two other groups (breast odor-301 s , controls-135 s). The data are consistent with the hypothesis that th e fetus may become familiar with chemical cues present in the intraute rine environment. Our data provide new evidence of the human baby's fi ne olfactory discrimination capacity, and add to the growing body of e vidence indicating that naturally occurring odors play an important ro le in the mediation of infants' early behavior. (C) 1998 Elsevier Scie nce Ireland Ltd.