Usually stretch marks can disappear about one year after a woman gives birth, the exact time varies from person to person. Stretch marks are a normal physiological phenomenon caused by the imbalance between estrogen and androgen secretion and the increase of melanin secretion during pregnancy due to strong metabolism. Usually, stretch marks will appear in the third month of pregnancy and disappear on their own about one year after delivery. However, individual pregnant women may not be able to disappear on their own due to too much pigmentation in the bottom layer of the skin and need to undergo professional repair under the guidance of a doctor. During pregnancy, women should pay attention to weight control and avoid oily food. After delivery, the use of corset, proper exercise and consumption of protein-rich food can help the stretch marks disappear.