The black line on the stomach after giving birth usually disappears in about 1 year, and the exact time varies according to the individual’s physique and skin condition. The dark lines on a woman’s abdomen after giving birth are called pregnancy lines, which usually appear during pregnancy and gradually become darker as they approach the expected date of delivery. Since everyone’s physical condition is different, the time for the stretch marks to disappear cannot be generalized. Generally, the stretch marks can disappear on their own about one year after delivery; some women may need a few months for the stretch marks to gradually fade or even disappear. Some women may need a few months for the stretch marks to fade or even disappear. In a few cases, the dark lines on the belly after childbirth can last a lifetime. Black lines on the belly of pregnant women are generally normal phenomenon, without special treatment. If they persist after delivery, women who need them may consider visiting a dermatologist for laser removal. In addition, it is recommended that women pay attention to keeping their skin clean after giving birth, adjusting their diets, and supplementing with foods rich in collagen, which is conducive to repairing damaged skin and accelerating the metabolism of pigments.