I think I read somewhere that sagging skin depends on genetics, skin elasticity and other factors. For example someone that bakes in the sun will have less elasticity. Also someone with thin, dry skin. Look at your mom for an idea of your skin elasticity. I think it is very individual, but I haven't seen too many post pregnancy bellies to be certain of this. Moisturizing helps and I heard dry skin brushing could help sagging skin. I believe prevention is a good thing too. For example wear sunscreen, moisturize, and massage your skin.