Re: Does anyone really go birth to potty in one size?
I voted newborn/os, but it isn't completely true. That worked for DD1, but DD2 outgrew the os at around 7-9 months (I was often asked if she was 2!). We switched to flats and nb covers + OS covers of my own design that fit MUCH better. I have a 3 mo and 23 mo (DD2) wearing the same covers. I do carry 2 different sized flats, but only because I prefer origami fold.