During the approximately 40 weeks of pregnancy, a woman's body undergoes some significant changes.

As the fetus grows, it occupies more and more space inside the mother. This is the cause of the obvious pregnancy bump, but just expanding outward isn't enough — her internal organs are also put under a significant amount of pressure, which can cause some discomfort.

That movement can also be pretty dramatic to look at. In the GIF below, which we spotted when it was recently tweeted out by the UK publication Scienmag, you can see those nine months of change sped up to just a few seconds.

The GIF is from an ongoing exhibit at Chicago's Museum of Science + Industry which shows the "impact of a pregnancy on a mother's body as she adjusts physically and mentally to the changes inside her."

If you go to the museum's website, you can actually play with an interactive slider that shows what's happening throughout pregnancy. During weeks 29 through 32, for example, they note that organs are being squeezed.

In the YouTube video below, you can see a slower version of the interactive, beginning near the start of pregnancy and going through birth.