you can already start applying to help skin retain moisture. but doin so won't 100% guarantee na di magkakstretchmarks, depende po sa genes and weight gain/ loss eto po ang mga known brands for stretchmarks prevention, lightening and improving its appearance Bio Oil Palmers Morrison buds and blooms may products din for stretchmarks lanbena ( please check safety for pregnant and lactating women) mustela and sanosan stretchmarks prevention products din