The formation of stretch marks is mainly influenced by pregnancy hormones. The swelling of the abdomen causes the elastic fibers and collagen fibers of the skin to be damaged or broken to varying degrees due to external forces. When taking a bath, first wash your abdomen and legs with a towel, then apply warm milk to your stomach and rub it with your hands from the inside out. Finally, apply slimming firming cream, which can tighten skin and promote skin metabolism.