Pregnancy may make your lips appear fuller and darker. This isn’t anything to be concerned about.

It famously happened to Khloé Kardashian. Beyoncé. Serena Williams. British soap star Jacqueline Jossa.

These power women all shared — often when prompted by questioning fans — that pregnancy gave them plumper pouts.

But are “pregnancy lips” really a thing — or are they just something celebrities claim to keep cosmetic procedures (like Botox lip injections) on the DL? Let’s take a look.

Related: Is it safe to receive Botox while breastfeeding?

Well, aside from the fact that many doctors advise against using Botox during pregnancy due to its unknown effects — and we refuse to believe that these celebrity women care about the health of their babies any less than the rest of us — there are other reasons to believe that lip changes during pregnancy may be more than a myth.

That’s right: While not one of the better known body changes during pregnancy, fuller lips might come with your fuller hips. And it might be for the same reason that your lips have their reddish color and you may have that famous “pregnancy glow.”

Just below the surface of your lips are tiny blood vessels known as capillaries. In fact, they’re what make your lips red.

Capillary density increases during pregnancy. (“Capillary density” is just a fancy way of saying number of capillaries in a certain area.) In addition — and especially during the third trimester — you’ll have increased blood flow as your body supports your growing baby. This causes blood vessels, including capillaries, to dilate (enlarge).

This is the theory behind the rosy cheeks of a “pregnancy glow” — blood vessels near the surface dilating. And all this adds up to the possibility of increased blood flow in your lips as well, which in theory could cause a plumper, fuller, or even redder pout.

Speaking of a redder pout, you may wonder if lips could darken during pregnancy for the same reason nipples do — increased melanin production due to having more of everyone’s favorite hormone, estrogen. But lips don’t have melanocytes, which are the cells that make melanin. So no, melanin won’t make your lips darker during pregnancy.

You may, however, experience dryer, more chapped lips while pregnant. This is because your body needs extra hydration during this time, making it more likely that you’re not getting enough if you’re continuing your prepregnancy status quo. And your body can retain what it does get, drawing moisture away from the surface. Dehydration can also be a side effect of hyperemesis gravidarum, or severe morning sickness.

So hit the water bottle hard and moisturize your skin and smile — your body and your growing baby will thank you.

And we’d be remiss if we didn’t also mention changes to your, well, other lips. Vulvar varicosities, or varicose veins of the vulva, are more common during pregnancy. They’re also related to increased blood flow and can cause the labia to swell.

There’s no need to treat fuller lips unless they’re causing pain or discomfort. In fact, Serena Williams eagerly anticipated and then celebrated hers.

For dry or chapped lips, keep chapstick on hand — and drink plenty of water.

If you have other concerns about changes to your lips — above or below — talk to your OB about it. They’ll be able to tell you if these are normal, expected symptoms of pregnancy.