What Does Being Pregnant Do To Your Body? Here Are 9 Effects You Didn't Know About, From Loose Joints To Extra Blood

Even if the closest you've ever gotten to interacting with a real live pregnant woman is owning the director's cut DVD of Knocked Up, you still have at least some awareness of the many pregnancy body changes that occur when one has a bun in the proverbial oven. There's the increase in breast size, the fluid retention, the...increase in breast size. OK, so you might actually not know as much as you thought about what happens to a woman's body while she's pregnant — which is a shame, because over the course of a nine- (really closer to 10) month pregnancy, a woman's body does some absolutely amazing, unusual, and totally wild things.

I mean, of course, the wildest thing that happens during a pregnancy is that your body cooks up an entire human being, just from stuff you had lying around in there (so, presumably, your baby is mostly made of Pop-Tarts, Chipotle, and gum you swallowed in high school). But while it's busy doing that, your body also goes through a wide array of other impressive changes to help you prepare for childbirth, from creating a whole new organ — the placenta —to making your muscles, hair, and even blood function differently.

Not all of the nine things below will happen to everyone single person who gets pregnant. But taken as a whole, these unexpected bodily changes show just how dynamic our bodies are, how much they are capable of, and how far they'll go in order to create another person. Read on, and if you're not a mom, soak in the knowledge — and if you are a mom, immediately call your child over and demand that they thank you for going through all this.

1. Your Joints Get Loose

The hilariously named hormone relaxin helps your pelvis and hip joints get loose and flexible enough so that you can push a tiny human being out of through a part of your body that, mere months ago, you have may struggled to push a super absorbency tampon into. Relaxin isn't picky, though — it causes all the joints, ligaments, and muscles in your body to relax and stretch, including muscles wildly unrelated to giving birth, like your knees (which can make your walk a little wobbly). Not cool, relaxin! I thought we were chill.

2. Your Feet Expand

That lovable scamp relaxin isn't done with you yet, though (I picture relaxin as wearing a backwards neon baseball cap and a tank top as I say all this, chugging a margarita and disdainfully saying "You know, you used to be cool"). Relaxin can also loosen the tendons in your feet — and that, combined the pressure of supporting your body at its full pregnancy weight, can actually flatten out your feet, making them wider, and in some cases permanently changing your shoe size.

3. You Breathe Differently

No, not because that little sucker in your womb is using up all the good air. Throughout your pregnancy — but especially during the third trimester — you may breathe faster and more deeply, and run out of breath quickly, because the uterus is pressing against the diaphragm.

The amount of blood in your respiratory system also increases during pregnancy, which can have unusual side effects, such as slightly changing the pitch of your voice or making you sound kinda perma-congested, a la Steve Urkel. All this is compounded by the hormone progesterone, which tells your brain to lower the levels of carbon dioxide in your blood, to support the growth of your baby. Taken all together, it may turn living in a walk-up into a daily 5K no-fun run, but everything will go back to normal after you give birth.

4. You're Nauseated For A Reason

We're all well acquainted with the image of the newly pregnant lady who can't stop tossing her cookies. But what seems like yet another pointlessly cruel punishment inflicted by that sociopath Mother Nature could actually have a developmental purpose. A 2008 study conducted by evolutionary biologists at Cornell University theorized that morning sickness developed as a protective mechanism for pregnant women, to keep them from accidentally ingesting tainted meats and other food that harbor parasites and could interfere with carrying a healthy pregnancy to term.

So if you've been permanently stationed by a toilet bowl for your entire first trimester, just think of it this way: if ancient humans hadn't had morning sickness, your cavewoman ancestors could have accidentally eaten some rotten tiger meat, and you might not even be here. Does that help? No? Sorry. No, I guess I didn't really think it would. Also, I'm sorry I mentioned rotten tiger meat while you're feeling sick. I'll just go wait over here.

5. You Have More Blood

With your body expanding and performing so many new functions, like maintaining the placenta, it needs more blood — this is why your blood volume can increase by 50 percent by your 20th week of pregnancy. The extra blood is responsible for the famous "pregnancy glow" — that rosy flush in your cheeks isn't excitement, it is an actual excess of blood running around under the surface of your skin. It is also responsible for the eerie phenomenon of pregnancy nosebleeds.

6. Your Teeth Get Sensitive

There's an old saying that women lose a tooth for every pregnancy. Luckily, that's no longer true (or most of our moms would probably look like they play defense for the Toronto Maple Leafs), but pregnancy can induce some strange dental problems. Increases in estrogen and progesterone can lead to gum sensitivity and gingivitis (which, luckily, goes away after the pregnancy has ended).

7. You Have A Harder Time Pooping

As your pregnancy marches onward, your uterus expands so much, you may be wondering where it all goes. Answer: it pushes out onto your rectum and lower intestines, applying pressure onto them and making it a real ordeal to get a decent poop out. The hormone progesterone doesn't help on this front, either — it encourages all your muscles to loosen as your body preps for pregnancy, including your sphincter, which does not make for an easy or fun pooping experience. And while all that fruitless pushing may help prepare you for the main event, it may also leave you with a different bundle of joy — hemorrhoids.

8. You Pee By Accident

While you're pregnant, your uterus presses down on all your important pee-related parts — like your pelvic floor muscles, bladder, and urethra — which is why many prego ladies constantly feel like a dam on the verge of bursting. This state of affairs means you may always be one sneeze or laugh away from taking an accidental bathroom break in your jorts. And thus, peeing a little by accident is a standard part of most pregnancies — I mean, what are you supposed to do? Spend nine straight months locked away in a tower? What if you come across a particularly hilarious bumper sticker? Don't fight it — a little pants-pee never hurt anyone (might as well practice saying that one now, right?)

Since childbirth can weaken the pelvic floor muscles, as well as cause damage to the surrounding nerves, giving birth can male you permanently more vulnerable to literally peeing your pants in laughter. But most of the time, Kegels and guidance from a doctor can help get you and your pee back on track eventually.

9. Your Skin May Change Color

Some women experience a temporary change in skin coloration on their face during pregnancy, which is called chloasma — but is also medically known by the super-ominous name "the mask of pregnancy." Seriously, guys? This is what passes for a legitimate medical name these days? What, was "the terrifying cloak of maternity" already taken? Anyway, despite having a name that sounds like a direct-to-Netflix slasher movie, "the mask of pregnancy" is just when some patches of skin, primarily on the forehead and cheeks, darken. 50 to 70 percent of all pregnant women experience some form of this, so it is totally normal, and if it bothers you, don't worry — it should go away once you push that little tenant out of your womb and into the world.

So there you have it — pregnancy is one of the most massively physically transformative experiences the human body could go through on its own. And your mom went through all of it, just to have you. Keep that in mind the next time she sends you a super annoying text reminding you to pack a sweater when you go out, OK?

Images: Jerry Lai/ Flickr, Giphy (9)