The Swedes have always been at the forefront of female empowerment. They were the first to experiment with rooming-in in the 1960s, taking what was once considered an enormous risk, that of having mothers looking after their own babies in the postnatal ward.

Then in the early 90s they published a paper in the Lancet 1, which observed a series of babies left alone on their mother’s tummy straight after birth. The babies were not touched, merely kept warm. After twenty minutes or so, the babies made crawling movements, then made their way up the abdomen and without assistance found their way to the breast, taking an average of an hour and a half for the journey. There they attached themselves successfully with wide mouth and an efficient latch.

The control group of babies who were removed, even briefly, to be dried, weighed, measured and then replaced with their mother, made no effort to find the breast, and tended to go to sleep.

It seems that babies following birth innately search for the breast as long as they are not interfered with. But how do they know which way to go? What draws them to the breast?

Information from baby rats (and many other animals) can help us understand. These young are born small, blind and deaf. The only sense they can use to locate and move towards the breast is that of smell. Wash the mother’s nipples and the rat pup is lost but the attraction is reinstated by painting the nipples with amniotic fluid (or mother’s saliva which, as she licks her genitals after birth, is also amniotic fluid). 2

The young of all placental species love amniotic fluid, its taste and smell. It’s what they’ve been gulping and swallowing all the time in the womb. It smells like home.

Now back to the human. We know that given a choice human babies prefer to turn to, and suck on, a breast coated with amniotic fluid rather than the unwashed, natural breast. 3 Through evolution we became erect biped apes and (unless you’re a contortionist or yoga teacher) we can’t lick ourselves after birthing and transfer the smell to the breast.

Evolution however found an elegant solution. Around the nipple in pregnancy we develop enlargement of our areola glands (also known as Montgomery glands). They secrete a sebaceous, moisturising and lubricating milky fluid. Chemical studies show that milk has volatile components similar to that of amniotic fluid. 4,5 That is, it smells the same.

So our babies have a smell beacon beckoning them to the breast,6 just like the rat!

This is yet another reason to spend time with your baby skin-to-skin following your birth. You get to know your baby, and the baby gets to know you, sight, sound, touch – and smell.

References

1. Righard L.,Alade M ‘Effect of delivery room routines of the success of first breastfeed’ Lancet (1990), 336: 1105-07.

2. Blass E. Teicher M. ‘Suckling’ Science (1980); 210, 15-22.

3. Varenti H, PorterRH, Winberg  ‘Attractiveness of amniotic fluid odour: evidence of prenatal olfactory learning?’ J Acta Paediatr (1996) 85: 1223-1227.

4. Naeslund, J. ‘The function of the Montgomery’s Tubercles’.  Acta Obst. et Gynae. Scandinav.(1957) 36:460 .

5.  Stafford M. Horning MG, Zlatkis A. ‘Profiles of volatile metabolites in body fluids’. J. Chromatograph(1976) 126. 495-502.

6. Doucet S. Soussignan R. Sagot P. Schaal ‘The Secretion of Areolar (Montgomery’s) Glands from Lactating Women Elicits Selective, Unconditional Responses in Neonates’ BPLoS One (2009);4(10):e 7579.