Stretch marks after pregnancy, mainly for the following reasons: First, because of hormonal secretion changes during pregnancy. Second, because the belly grows day by day, for the skin caused by excessive stretching, protein collagen fracture damage caused by. Because of your own body type and genetic reasons, it is recommended that you should control your weight during pregnancy to avoid excessive weight gain. You can increase skin elasticity and apply some local oils, such as olive oil, vitamin E, essential oil, etc., which can lighten the stretch marks. Eating more vegetables, fruits, lean meat, etc. and drinking more water to speed up metabolism can effectively prevent stretch marks.