As someone who has given birth to three children and who was raised by a labor-and-delivery nurse, you'd think I'd have a good handle on the physical mechanics of childbirth. But despite knowing all the terminology and experiencing all the details first hand—uterine contractions, cervical dilation, etc.—I'm a visual person, and most of the birth process happens internally. Feeling it and being told what's happening isn't the same as being able to visualize what's actually happening.

Enter high school teacher Brooke Bernal, who teaches consumer sciences. She shared a video on TikTok demonstrating how she teaches her students about childbirth, which she says is her "all time favorite lesson," using a balloon and a ping-pong ball. It's a simple, but-oh-so-helpful demonstration that even helped me get a better grip on the miracle of childbirth. (Without the baby shooting across the room at the end, of course.)

Bernal explains that the big round part of the balloon is the uterus, the skinny tube part is the birth canal, and the opening is the cervix. Then she puts a ping-pong ball into the balloon and shows how the pressure of the contractions causes the ball baby to push on the cervix, causing it to thin out (efface) and open up (dilate).

There's one little hiccup with this demonstration, which is that the "birth canal" isn't actually above the cervix like shown in Bernal's video. The cervix is immediately outside of the uterus, and then the birth canal is the vagina below that. So in a real birth, what you see happening with the cervix would happen before the baby goes through the birth canal (and is, in fact, what allows the baby to do so).

A video that may have served as the inspiration for this one (Bernal told Buzzfeed that she had seen the idea shared in a teacher group on social media but wasn't sure where it came from) illustrates that a bit more clearly:

Use a balloon and ping pong ball to show how the cervix thins and dilates during laborwww.youtube.com

Aside from the birth canal bit, Bernal's video is great. The first awesome part is how she illustrates the difference between Braxton-Hicks contractions and real contractions. For those who haven't experienced the joy of thinking you were in labor half a dozen times before you actually were, Braxton-Hicks contractions are basically practice contractions. It's your uterus running drills. Some people have them for weeks before real labor starts, and they can be pretty uncomfortable..

Real contractions come from the top of the uterus and actually move the baby down into the birth canal. This part of the video makes that difference so clear.

The other part that I found helpful was the effacement and dilation illustrations. Not being able to see your own cervix, it's hard to imagine what a midwife or doctor means when they tell you you're "90% effaced" or "7 cm dilated." You can see it in drawn diagrams, but I don't find those nearly as helpful as watching that balloon opening get thinner and wider as the ball was being pushed down.

"Normally, this demonstration does not faze my students at all," Bernal told Buzzfeed. "They are really just surprised that a ping pong ball can fit into a balloon and that a balloon can stretch like it does without popping. It's just a good visual aid for them."

"And, yes, they know a baby will not actually yeet across the room!" she added. "I personally feel that they get more out of me showing it this way than they would watching birthing videos because it's something that is hands on and they can't just zone out."

I will say, though, that as illustrative as it was to see the mechanics of contractions, effacement, and dilation goes, it's definitely a limited demonstration. First of all, babies are nowhere near the size of a ping-pong ball, and that whole contraction > effacement > dilation > baby popping out process takes a heck of a lot longer and involves a crapton more work than that. It doesn't even touch on the reality of what our bodies go through and what it's really like to grow an entire human being and then push it out through an opening that does not look or feel nearly large enough to do so.

So yes, this demonstration (with the caveat about the birth canal) combined with some real-life footage would go a long way in helping people understand what's happening during childbirth.

Well done, Ms. Bernal.