I was back to pre-preg weight on day 4 (i only gained 6kg) and was way thinner a few months later. BUT i had the distance between my hipbones measured before i got PG (the bones, not the flesh) and they are wider now, by 4mm (hardly enough to make clothes not fit) and by 6mm if i have AF (you have more relaxin in your system when you have AF, which is why the cervix is low, because the uterine ligaments relax). In terms of clothes i am 3 sizes smaller, but in terms of bones i am 4mm bigger.

To be honest i think it is only the naturally very slender, whose clothes are actually against bone rather than chub (like mine are LOL) who would have clothes not fitting because of the bones having spread. Like, we often notice our shoes don't fit, because feet are basically all bone so when they grow we really notice, if that makes sense.

Bx