The formation of stretch marks is mainly due to the hormonal influence of pregnancy, with the growth and development of the fetus, coupled with the expansion of the abdomen so that the elastic fibers and collagen fibers of the skin damage or break, the abdominal skin becomes thinner and thinner, and in the location of the break appears in different widths and lengths of pink or purple wavy patterns. After delivery, the pattern will basically disappear. If the disappearance is not complete, a spot-like pattern will appear, which is called stretch marks. Whether or not stretch marks appear after pregnancy or how early they appear varies significantly from one individual to another and cannot be generalized. Generally, stretch marks are formed in the middle of pregnancy, when women are most affected by hormones. In the case of a woman with a normal body type, basically, the breakage of elastic fibers may occur at 5-6 months of pregnancy, resulting in the formation of pink marks, and at around 8 months, if such marks do not appear, they will not appear. Therefore, stretch marks are a normal physiological phenomenon of the body and can be healed basically without treatment. At the same time, stretch marks can also be prevented by taking certain measures, such as pregnant women can prevent or alleviate the appearance of stretch marks by properly controlling their diet, not eating too much high-salt, high-fat, high-sugar food, and avoiding excessive weight gain in a short period of time.