3 Uterus facts everyone should know

What is a uterus?

The uterus, or womb, is the name for the muscular internal organ of the female reproductive system. The uterus is hollow and shaped like an upside-down pear. During pregnancy a fertilized female egg cell (or zygote) implants in the uterine wall, growing inside the uterus, developing into a fetus before birth.

What else should I know?

Now we’ve defined what a uterus is, where it’s located and its role in our reproductive system, let’s dive a little deeper and unpack some lesser-known facts about this incredible organ… 

1. The uterus is super stretchy

Most of the time our uteruses are surprisingly little, only about two-and-a-half inches wide or the size of a small apple. During pregnancy the uterus stretches, and by the end of pregnancy, the uterus is the size of a watermelon! That’s pretty stretchy…

After giving birth, the uterus shrinks back down again. This can take around six weeks, a process known as involution. We think that’s pretty impressive! No other organ can stretch that much without causing permanent damage.

2. The womb doesn’t wander, but it can tilt!

The Ancient Greeks believed that the uterus had a tendency to move around the body and this ‘wandering womb’ was responsible for women’s health problems, especially ‘hysteria’. In hindsight, this seems laughable. Like all of our organs, the uterus isn’t free to drift away at any moment and the wandering womb is just another throwback to the stigma and misinformation around female reproductive rights. While wombs never wander, there is, however, such a thing as a tilted uterus. In most women, the uterus is tilted forward, towards the belly button. However, some women have a reverse tilted uterus, pointing backward. 

This is actually pretty common, with an estimated 1 in 5 women’s uteruses tilting in reverse. Most women with a tilted uterus might not even know that they have one. In some cases, inserting tampons can be tricky and certain sex positions may be uncomfortable. We always recommend consulting with a healthcare professional if you have questions or concerns about your reproductive health. 

3. Some women are born without a uterus

In some rare cases, women are born without a uterus, this is called Mayer-Rokitansky Küster-Hauser syndrome (MRKH). Although the internal reproductive parts can be underdeveloped or missing entirely, the vulva might not look any different. In recent years, uterus transplants have become possible, with the first baby born from a uterus transplant delivered in Sweden in 2014. Only around 1 in 4,500 women are born without a uterus.

There is another very rare condition where women are born with two uteruses, this is called uterus didelphys. A woman born with two uteruses may also have two cervixes, and two vaginas. It’s still possible for women with two uteruses to conceive and experience a healthy pregnancy, though this condition is extremely rare.   

Discover more about your body with hormone-free birth control

We hope you’ve discovered something new about the uterus! Learning about our reproductive health is an on-going journey, one we are proud to prioritize at Natural Cycles. Our mission is to pioneer women’s health with research and passion – by empowering every woman with the knowledge that she needs to be in charge of her health. Natural Cycles is more than a period tracker, it’s an app that can help you prevent or plan a pregnancy by giving you the tools to know your own fertility. It’s also completely hormone-free.