8 Surprising Ways Your Pregnant Body Changes During the Third Trimester

Caroline Olney | Feb 27, 2015 Pregnancy

It's the period of pregnancy you've been waiting for! Well ... almost. The third trimester of pregnancy is when most of the BIG (and by that, we mean your tummy) changes happen to a pregnant woman's body -- as you've probably noticed. But what's really going on beneath all that glowing and gorgeous skin?

From an increase in the amount of blood pumping through your veins to some eye-opening optic differences, the body in the last 12 weeks of pregnancy is an amazing thing. Check out eight of the biggest things that happen in the last three months of carrying your baby.

What's the biggest body chance you noticed?

Image via YanLev/shutterstock

  • You have 50 percent more blood than you’re used to


    Image via Image Point Fr/shutterstock

    By week 35 of pregnancy, the average woman has created an extra 1.32 quarts of blood. That’s a little less than half of the non-pregnant volume for an average-sized woman. What’s it all doing? Well, bringing oxygen to your organs on overdrive and bringing life to your baby. 

  • The amount of plasma in your body increases by 45 percent


    Image via 2nix Studio/shutterstock

    If you've ever given blood, you've probably heard of plasma, a pale yellow liquid that helps hold the cells in your blood. Though the number can vary widely, on average a pregnant woman has 45 percent more plasma than a non-pregnant woman. In some women, their plasma volume doubles or more! All this extra plasma serves the placenta and through it, the fetus, but it also helps out all of your organs that are working on overdrive.

    More from The Stir20 Craziest Things Pregnant Moms Have Done While 'Nesting'

  • Your nerves get squished


    Image via Image Point Fr/shutterstock

    Image via Image Point Fr/shutterstock

    This is usually because of all the extra fluid in your body and because your growing uterus is pushing all your other organs out of its way. The most common places you'll notice this is in your legs -- which are probably cramping during the night -- and in your wrists. When it's in your wrists, it's called Carpal Tunnel Syndrome, and it affects 62 percent of pregnant woman. Good news? It usually goes away after the baby's arrival.

  • Your blood becomes more acidic


    Image via MitarArt/shutterstock

    Moms-to-be breathe heavier in their third trimesters because of their body's increased demand for oxygen and the fetus’s growth. This results in a condition called respiratory alkalosis, which elevates the pH of your blood.

    More From The Stir: 8 Surprising Ways Your Pregnant Body Changes During the First Trimester

  • Oxygen intake increases by 20 percent.


    Image via wavebreakmedia/shutterstock

    There are a lot of factors in play that cause this one -- not only is your metabolism getting a kick-start, you’re also breathing heavier and more often (if you haven’t noticed already). Add to this that your little baby-to-be is metabolizing more and more himself, and you’ve got yourself a recipe that requires a lot more oxygen.

  • Your eyeballs change shape.


    Image via Voronin76/shutterstock

    Strange, right? Most experts agree that your eyes change shape because of all the water your body is retaining mixed in with all the new hormones. Either way, it means that your vision can actually change, and chances are you’ll be more nearsighted than you were before. But this doesn’t mean you should run off to get Lasik – your eyeballs should return to their normal shape in the months after you give birth.

    More from The Stir15 Gross Pregnancy Symptoms That Stick Around Long After the Baby Is Born

  • The level of calcium in your body drops


    Image via Ermolaev Alexander/shutterstock

    Don’t worry, it’s not dangerous. But interestingly, women in the third trimester of pregnancy have 5 percent less serum calcium than women in the first trimester of pregnancy.

  • Your voice lowers.


    Image via Chrystya/shutterstock

    Though the scale of the drop will change from woman to woman, you’ll probably notice a drop in the pitch of your voice, especially if you’re a singer or use your voice a lot. The changes are probably because of mild swelling of the vocal folds that relates your increased fluid retention. All the extra mucous in your body probably isn’t helping, either.


3rd trimester

More Slideshows