The Reality of Pregnancy Stretch Marks: 7 Things You Must Know

What Causes Stretch Marks?

It’s all about the connective tissue beneath your skin. This tissue is rich in collagen and elastin, which give your skin strength and flexibility. But when your skin stretches too fast—whether from pregnancy, weight gain, or fluid retention—the collagen bundles can tear. When the body repairs these tears, it leaves behind tiny scars: stretch marks.

Hormonal changes during pregnancy also play a big role. Hormones like cortisol soften the connective tissue, making it more vulnerable to tearing as your belly expands.