Tinéo's P'tit loup collection features a sleeping bag in several sizes: the birth sleeping bag, the 3 - 9 months sleeping bag and the evolving sleeping bag, so you can find this adorable pattern in several sizes. Tinéo's P'tit loup collection features a sleeping bag in several sizes: the birth sleeping bag, the 3 - 9 months sleeping bag and the evolutionary sleeping bag, so you can find this adorable pattern in several sizes. On Le Choix Des Bébés you will find a large choice of sleeping bags in different sizes, for birth but also evolving sleeping bags very practical when baby grows. The 3 - 9 months sleeping bag is a good intermediary because it will allow you to cover your baby from birth and will allow you 6 months before changing size. It is important to choose a sleeping bag adapted to baby's size because the purpose of a sleeping bag is to reassure baby during his sleep. A baby needs to feel supported and wrapped when he sleeps because it reminds him of the sensations he experienced in utero. That's why a sleeping bag for newborns or 3-9 months old will be very well adapted for a newborn baby. When he grows, the feeling of being wrapped up is always desired but he must also be able to be free to move around. That's why the evolving sleeping bags are very practical for baby. You will also need to choose a sleeping bag model adapted to the season, i.e. either a winter sleeping bag or a summer sleeping bag, in order to avoid baby getting cold or sweating.