Babies recognize their mother's scent even before they are born. Your baby is biologically and genetically programmed to connect to you through your unique smell. The process of development of olfactory cells (cells responsible for the sense of smell) begins as soon as the first trimester of pregnancy.
Yes, newborns recognize your scent within days of birth — but can newborns smell you when they sleep? Though there are mixed reviews on whether or not it's a good thing that they can smell you when you sleep, the general consensus seems to be, yes, they can smell you when they sleep
Do newborns know their moms smell?
