Some pregnant girls get striae in the skin. what i have to do for the striae to disappear?

They won't: Stria occur when the skin is stretched beyond its elastic limit and undergoes permanent deformation. If you stretch certain kinds of rubber they behave in a similar manner. Once the stria have been created, they may improve a bit in appearance but will not disappear. If the stria are in certain places, like the lower part of your abdomen, they can be removed surgically as is done in a tummy tuck.

Unfortunately nothin: Unfortunately, those striae are stretch marks and stretch marks are scars. Once a scar, always a scar. Once the stretch is gone (after delivery) the marks will fade but they will always be there.

Stretch marks.: Striae, or strtch marks, are separations (tears) in the dermis, the deeper layer of the skin. Once the form, they cannot be repaired. They tend to become less noticeable with time, and lasers can help lighten red or purple marks. Moisturizing and massage can help decrease their formation, but unfortunately they are caused my stretching and increased by hormones.