Stretch marks are beautiful signs of the baby who grows within you—but to be honest, they're something most women would prefer to avoid if possible. About 90% of pregnant women will develop stretch marks at some point in their pregnancies, so if you're one of them, be sure: You're so not alone, mama! We talked to dermatologist Dr. Rosy Chattha, MD, about where these little lines come from, and what (if anything) you can do about them.

Here's what Dr. Chattha says about stretch marks:

A photo posted by Cecilia (@ceciliaharvard) on

Stretch marks, also referred to as striae, will affect most women during pregnancy.

These small tears in the deeper layers of the skin occur when the skin expands to accommodate the remarkable growth of the baby over a relatively short period of time. The increased levels of hormones during pregnancy also play a role, and your genetics may determine how susceptible your susceptibility to the extent of the stretch marks.

The best way to minimize or possibly even prevent stretch marks is to follow your doctor's advice for steady and healthy weight gain.

Daily moisturizing will improve the suppleness of the skin, but apart from feeling good, it has no scientific basis for treating stretch marks. Stretch marks form in the deeper layers of the skin, far below the reach of surface creams and oils.

And be careful with what you slather on your body. Think about it—would you want something that you apply to the surface of your skin to get absorbed into your body, especially if you are pregnant? There is a reason that healthy skin is a barrier.

"Her stretch marks were lighting stripes of life, proving she could weather the storm."
A photo posted by Cecilia (@ceciliaharvard) on

After pregnancy and breastfeeding, more options are available.

Retinoid-containing creams improve the texture and appearance of stretch marks presumably by increasing collagen and elastin production.

Vascular lasers can reduce the reddish-purple appearance by targeting the new, abundant small blood vessels within the stretch marks.

Once stretch marks settle into less noticeable silvery lines, retinoid creams and vascular lasers are not as effective. At this stage, one option is treatment with a fractionated laser.

This is the only evidence-based treatment.

My bottom line: Don't spend money on expensive creams that claim to prevent or treat stretch marks. Instead, simply moisturize with what feels good and eat a sensible diet and exercise to keep weight gain in a healthy range.

Save your money for laser treatment after you're done nursing, if you're so inclined.

Remember, 90% of women will develop stretch marks during pregnancy. Give yourself a break and try to see the lines as a small price for a beautiful purpose.

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