Not all pregnant women get stretch marks. First, let’s understand what stretch marks are all about. Stretch marks are small, narrow lines that appear on the skin of pregnant women during pregnancy, and they appear after the middle of pregnancy as the fetus grows. Stretch marks usually appear on the abdomen, thighs, and hips of pregnant women, and they can be very distracting, especially for mothers who are very fit and fashion forward. Why not all pregnant women will have stretch marks? First, genetic factors, these pregnant women are susceptible, the skin itself is poor tension; second, dry skin, or the use of some hormone creams led to poor epidermal tension, can not withstand the tension of the dermis; third, rapid weight growth, resulting in rapid expansion of the skin. The speed of this tension is far more than the skin can withstand. All three of these conditions can lead to a break in the collagen fibers, resulting in stretch marks. So not all pregnant mothers will get stretch marks.