Volatile signals during pregnancy: a possible chemical basis for mother-infant recognition

Human pheromones play a role in regulating relationships and apparently influence partner choice and mother-infant recognition. We analyzed the chemical content of volatiles from sweat patch samples from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. Solid phase microextraction was used to extract the volatile compounds, which were then characterized and quantified by gas chromatography-mass spectrometry. During pregnancy, women developed a distinctive pattern of five volatile compounds common to the para-axillary and nipple-areola regions (1-dodecanol, 1-1'-oxybis octane, isocurcumenol, alpha-hexyl-cinnamic aldehyde, and isopropyl myristate). These compounds were absent outside pregnancy and had slightly different patterns in samples from the two body areas. Differentiation of the volatile patterns among pregnant women may help newborns to distinguish their own mothers.