From Milky Way X-Press
Volume 2, # 2
The Smell of Amniotic Fluid: A Bridge for Baby Between The Old World and New?
Beverly Morgan

Human infants are particularly responsive to smell. Beginning within minutes of birth, babies are attracted to breast odors associated with the nipple/areola that may reflect prenatal exposure and familiarization. To some extent, the
chemical profile of breasts secretions overlaps with that of amniotic fluids. Newborns are generally attracted to breast odors produced by lactating women. Breastfed infants rapidly learn to prefer their own mother’s characteristic smell
and can recognize her by that unique scent alone.
"Unique Salience of Maternal Breast Odors For Newborn Infants", Porter RH,
Winberg J, Laboratoire de Comportment Animal, CNRS/URA 1291, INRA, Nouzilly, France
Neurosci Biobehav Rev, 1999; 23 (3): 439-49
http://www.ncbi.nlm.nih.gov/htbin-post

A journal article reported the responses of newborn babies to amniotic fluid during their initial attempt to locate the mother’s nipple/areola all babies had been washed before observation. Only 12 out of 30 had suckled on their hands/fingers prior to approaching the nipple/areola. This is in contrast to previous work done with unwashed newborns where the corresponding proportion was 27 out of 30. The authors observed that the newborn had an attraction to the smell of amniotic fluid. They postulate that products [editors note: or procedures such as washing the baby] that remove, or mask, the smell of amniotic fluid should be avoided during the preinatal period so as not to hamper the infants attempt to initiate breastfeeding.
"Attractiveness of Amniotic Fluid Odor: Evidence of Prenatal Olfactory Learning?"
Varendi H, Porter RH, Winberg J, Department of Pediatrics, Tartu University,
Children’s Hospital, Estonia, Acta Paediatr, 1996, Oct;85 (10): 1223-7,
http://www.ncbi.nlm.nih.gov/htbin-post

At their first sucking contact, neonates prefer an unwashed breast to a washed one, but an amniotic fluid treated breast over a "natural odor" breast. On day 3-4 significantly more babies still selected their mothers unwashed breast than the washed alternative. In a follow-up experiment, the number of babies who selected a naturally scented breast rather than an amniotic fluid treated breast on day 2-5 were not reliably different. However, babies who selected the natural breast had longer pre-test maternal contact and had spent more time breastfeeding. Ten babies who chose the amniotic fluid treated breast were again tested in the same manner several days later: all preferred the naturally
smelling breast. Conclusion? While preferences for amniotic fluid treated breast fade after birth, responsiveness to natural breast odors may be enhanced by postnatal experience.
"Natural Odor Preferences of Newborn Infants Change Over Time", Varendi H, Porter
RH, Winberg J, Department of Pediatrics, Tartu University, Estonia, Acta
Paediatr, 1977, Sept: 86 (9): 985-90, http://www.ncbi.nlm.nih.gov/htbin-post

Another project looked at the initial pattern and development of odor preference in infants. It divides the process into 2 phases:
1) The Initial Stage (days 1-3) and before 7-12 breastfeeding episodes: No evidence of differentiation on amniotic fluid and maternal lacteal secretion (colostrum/milk) was found.
2) Days 4-5 and 7-12 breastfeeding episodes, infants showed a significant preference for lacteal secretions.
The authors theorize that the second stage may reflect the infant’s perceptions of change in milk quality and increasing experience with milk.
"Orientation Responses to Biological Odors in the Human Newborn," Marlier L, Schaal B, Soussignan
R, Laboratoire de Comportment Animal, CNRS EP 618,
Universite Louis-Pasteur, Strasbourg, France, C.R Acad Sci IIIm 1997, Dec;320
(12): 999-1005 http://www.ncbi.nlm.nih.gov/htbin-post

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