Baby sleeping bags Get baby’s sleeping in the bag! Depending on where you’re from, when and how you use baby sleeping bags may differ. In northern countries (think Scandinavia), they’re traditionally used from birth, while southern European parents (in France, Italy, Spain etc.) swear by baby sleeping bags during at least the first year. In terms of size, baby sleeping bags are available for newborns up 2 to 3 years. For premature babies or ones that are especially tiny, Numero 74 offers ones in size 0. GARBO&FRIENDS “Apple” sleeping bag in cotton, Greenable 56