The Maxaloons range are  grow with my style leggings from newborn up. Start by folding up for leg cuffs to make as small as possible, then as baby grows, unfold the cuffs bit by bit until they are all the way unfolded
 
Squishiloones from NB which can reach up to 6 months
Maxaloons (size 1) fit from about 3 months up to 3 years
Monsterloons (size 2) fit from about 1 year up to 5 years
 
These squishiloons are a flying pets in planes with mint expandalble bands and bum circle
 
Cotton 95% Lycra 5% jersey fabric. Wash with similar colours on 30 and line dry. Cool iron