Familiar smells help calm newborns

The smell of amniotic fluid can relax newborns separated from their mothers after birth, according to a study reported in the April issue of Early Human Development (Vol. 51, No. 1, p. 47?55).

Vanderbilt University psychologist Richard Porter, PhD, and his colleagues tested the reactions of 47 newborns to the smell of their own amniotic fluid and their mothers? breast milk. For an hour and a half soon after birth, the researchers recorded babies? cries as they lay on examination tables, wrapped in cotton blankets under radiant heaters. The researchers placed a sterile cloth moistened with a newborn?s own fluid near 16 infants? noses and a cloth moistened with mothers? breast milk near 15 newborns? noses. Sixteen babies were not exposed to any special odors.

The babies exposed to their own amniotic fluid cried an average 29 seconds compared with 301 seconds for babies exposed to breast milk and 135 seconds for babies exposed to no special odors. The amniotic fluid odor lowered the amount of crying time almost as much as when mothers hold their newborns, Porter found.

The increased crying triggered by breast odor may indicate that babies were upset because they couldn?t find the source of food associated with the smell, says Porter. These results add to a growing body of evidence that odors strongly influence newborns? early behavior. Porter?s earlier work found that babies locate their mothers? nipples by their scent.

?B. Azar