The human body is amazing. And when a body is giving birth, well, it’s just about the most mindblowing thing out there. (This includes when that body is giving birth via Cesarean section).

Sometimes it can be hard to wrap our minds around what exactly is happening in the body during labor and birth. For many people, the first time they experience birth is their own. We only really learn about the process in birth class—and even then it’s pretty mysterious!

That’s why we love the creative people on the internet who share their visual demonstrations of what exactly happens during labor and birth. The most recent demonstration to take the internet by storm is a TikTok video by certified nurse-midwife, Sarah Pringle (@midwifemama).

In this video, Pringle uses a model of the cervix to show what the cervix looks like in labor as it changes to allow the baby to be born.


#greenscreen we need more discussions and media attention regarding pain management during medical procedures like IUDs

♬ Bad Little Thing – Noa Kirel

Sigh, the human body is just so cool.

The cervix is the opening of the uterus. It’s at the bottom and it looks like the stretchy neck of a balloon. Check out this image by Stepha Lawson in “The Motherly Guide to Becoming Mama” to see what the cervix looks like:

reproductive anatomy ‘The Motherly Guide to Becoming Mama’

As I share in “The Motherly Guide to Becoming Mama,” the cervix does three things when you are in labor:

  1. It softens. Tap your chin. That’s about the firmness of your cervix when you are not in labor. Now tap your cheek. That’s how soft it will get.
  2. It effaces, or thins and shortens. We measure this in percentages. Throughout pregnancy, you are likely 0 percent effaced. When your cervix has thinned halfway, it is 50 percent effaced, and when it is as thin as paper, it is 100 percent effaced.
  3. It dilates, or opens. Before labor, your cervix is “closed.” Of note, some people do start to dilate before they are in labor, especially if they have had vaginal births before. As labor progresses, your cervix gradually opens. We measure this in centimeters. A “fully dilated” cervix is 10 centimeters wide—about the diameter of an average-size bagel.

The cervix does these 3 actions in response to contractions, which slowly pull back on the cervix to allow it to dilate.

In labor, cervical exams are done to assess how labor is progressing. The provider will ask your permission (this is key) and then insert two fingers (wearing sterile gloves and using lubrication) into your vagina and back to your cervix. We feel for the parameters of the cervix and can tell how dilated the cervix is based on the diameter. So for example, I know that if I can insert the tip of one finger into the cervix, it’s one centimeter dilated, two fingers side by side is three centimeters dilated, and when I can spread my fingers as wide as they’ll go and can’t feel any more cervix, you’re fully dilated—and it’s showtime.

Want to learn more about the amazing body in labor?