Babies’ sense of smell, called “olfaction,” is highly developed at birth. Scientists think a baby’s ability to smell his mother is one of the important ways he learns to recognize her. Newborns spend a lot of time with their eyes closed. Researchers have found that newborns are able to tell the difference between the smell of their mothers and the smell of other women (yes, they really did a study!). Babies’ early exposure to a smell (in the first couple of hours after birth versus more than 12 hours after birth) results in a stronger and longer memory of the smell. This may be because newborn babies learn from their senses best when they have high levels of the hormone norepinephrine and this hormone is high in most babies in the first few hours after they are born.
Babies don’t have the ability to know what smells are; they won’t know a flower or diaper by its smell – that takes experience. But, babies are calmed by familiar smells that they associate with good experiences (like a loving touch or breastfeeding). In contrast, babies may turn away from strangers with strong unfamiliar odors, so you might ask Aunt Sara not to wear too much perfume when she comes to visit!
Because babies are more likely to remember the odors they were exposed to very early in life, they are more likely to be familiar with and calmed by the smell of their own mothers – since she’s right there after birth. These studies do not mean that babies won’t be able to recognize their mothers’ smell if they are not with her in the first hour or two, but it might take longer than those who are physically close to their moms earlier in life.
Skin-to-skin contact for about an hour immediately after birth increases babies’ recognition of the smell of their moms’ milk at 4 days postpartum. Early skin-to-skin contact has many benefits for mom and baby and many hospitals encourage the practice immediately after birth, during the best time for learning. Dads can make sure that baby is familiar with their smell by cuddling close early and often!
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