That's called stretch marks, because pregnancy is influenced by hormones. The swelling of the abdomen causes the elastic fibers and collagen fibers of the skin to be damaged or broken to varying degrees due to external forces, and the skin becomes thinner and thinner, and some pink or purple wavy patterns with different widths appear on the abdominal wall skin. After delivery, these patterns will gradually disappear, leaving white or silvery shiny scar lines, that is, stretch marks.

But it will gradually fade over time.