How to avoid sagging skin on the tummy area

Cadelaria

I could say that I was fit and had a flat tummy prior to my pregnancy with my son. When I gave birth, there's a little sagging skin but I could still wear my swimsuits and fitted tops like I haven't given birth at all. Through the years I have gained a lot of weight perhaps because of age, being busy with work and family and being not too conscious on my figure. Now I'm wondering, if I do get pregnant, how do I avoid having sagging skin on the tummy area? I feel like I'm so sure that I will have a sagging skin coz of the extra inches I've gained around my waist... Care to share any tips? Thanks!