Baby’s sense of smell is one of their most developed senses at birth – when they were still only capable of seeing and processing things 8 to 12 inches away, they were already able to smell as well as you could, and in some specific instances, even better. By the time Baby is a few hours old, they can differentiate their mother’s scent from all other smells, as long as they have had some skin-on-skin-contact to learn it.
Baby‘s sense of smell isn’t the over-achieving sense out of nowhere, though – their ability to smell has been developing since their nasal cavity started to separate from their mouth at around 9 weeks of gestation, and has been fully functional since some time between 30 and 33 weeks of gestation.
For a long time, scientists believed babies in the womb had no sense of smell because instead of breathing air, they inhaled amniotic fluid. However, studies now show that newborns only a few hours old recognize the scent of their mothers’ amniotic fluid, proving that a sense of smell becomes fully developed in the womb and suggests that scent plays a part in the taste-preferences babies develop before they’re born, based on their mothers’ diets.