Stay hydrated, and I put on argon oil on my belly after shower first, and body cream all over my body, and then over the oil once it’s dry. If my belly doesn’t feel moisturized I do the oil again as needed.
Not much can prevent stretch marks but just drink lots of water and keep your skin hydrated so you don't itch. I like Burt's Bees Mama Bee Belly Butter. It's unscented which is amazing.