Why You Didn't Die at Birth - Smarter Every Day 42

Hey, it's me Destin. Welcome to Smarter Every Day. So, today's episode's a little bit different. I have a question about breathing. It's pretty simple. See, our bags are packed and we're about to go to the hospital to have our third child, and my question is this: How do you go from "this is my baby" in my baby to "this"? Now, 72 hours ago, my son was inside my wife, and now he's not. He's no longer in a liquid environment; he is in a gaseous environment. So, something has to change, and in fact, it's awesome.

To learn more about this, let's go talk to somebody that's smarter than me. Well, my wife could do it, but she's tired. Goodnight! - Goodnight. Alright, so to figure out how babies go from living in a liquid environment to an air environment, we had to come to a smart guy's house, so we came to a doctor's house. Spiral staircase, you know he's smart. So, let's go check him out.

Hey, how's it going? - Hey Destin. So, this is Dr. Schuster, and Dr. Schuster is a baby delivery doctor we'll call you for the video. - Alright. So, he also plays music, so that lets you know that he's really, really smart. So, we're gonna get some info from him. [music]

Okay, so my question is pretty simple. How do we go from breathing fluid inside the mother's womb to breathing air? - As the baby's coming out and gets squeezed as it's coming through the birth canal, all that fluid that's been in the lungs, which is the urine from the baby and the poop from the baby, I mean all the bad stuff. Once they get squeezed, that stuff comes out, and that baby takes that very first gasp, that gasp of oxygen. The thing that that baby needs. That triggers huge changes in the circulation of the baby, and that's what allows everything to start working; the baby's breathing on its own then.

So there's actually like a switch that's flipped or something when the baby breathes for the first time? - A couple of valves that change the circulation, change the plumbing, if you will, in the heart. Really? So, where are these valves? These valves are actually in the heart? - The top half of the heart, yeah. There's something called the foramen ovale, which is just a big flap that sits between the right and left atrium. It closes once that baby gets that first little bit of oxygen, that first breath.

Okay, so that's pretty amazing. So, the first time the baby takes a breath, and that's why that first cry is so special because that's actually [clicks fingers] the moment where the baby's autonomous. - It's all breathing. Yeah, it goes from breathing its own poop to breathing real oxygen, the real nutrients that it needs for life. Oh, that's awesome. Thank you very much. - Anytime. Glad to do it.

Alright, we got a little man. Let's check him out. He's alive and well, and his lungs are working and he's breathing air. One thing that happened right when he came out is this right here. After he started squealing a little bit, I could hear that [clicks fingers] change when he went from fluid to air. The nurse brought him over here and she stuck this tube down his throat, and she starts sucking amniotic fluid. This little guy started telling us what he thought about everything. So, check him out. Get in there, see his face. Mmmhmm.. That's what I'm talking about.

Check this out. It's an ultrasound from 5 months ago when he was still in the womb. This is real data. If you look close, you can see all four chambers of the heart. If you look even closer, you can see that little thing that Dr. Schuster was talking about.

Okay, I didn't understand that, so I had to get my wife to put it on engineering paper so I could figure it out. So, in your heart, you have four chambers, and the blood, as it exits the lungs, it goes through the heart and comes back to your body. And after it exits your body, it goes back through the heart and then goes back to the lungs. We all know this, but here's the deal with the heart before the baby comes out of the womb. You have something here called the foramen ovale, and you have here something called the ductus arteriosus.

[newborn noises in background] I hear you, buddy, hold on. So what's going on here is, before birth, the foramen ovale and the ductus arteriosus divert blood from the lungs, so what that means is only about 7 percent of the blood flow goes to the lungs.

[infant crying] Daddy's here, hold on. So, basically, before birth, the lungs are really, really small. They're not inflated because the foramen ovale and the ductus arteriosus, which is right here, diverts that blood flow. So, once it flips over, the foramen ovale closes in about an hour, and the ductus arteriosus goes away and becomes a ligament after about 5 days.

I think this is really awesome. You can see that the blood flow goes back to 100 percent for the lungs, and the... Alright, I'll... [baby crying] I can get him. You're getting Smarter Every Day.

The nurses are gone, so I started messing around with their stuff. Woah. Check that out. Alright. Now we turn on a super light. This is, this is active tracking. You asleep? - Not anymore. Just bear with me. Look at this, I found a magic wand. What? Alright, so watch this.

So, there's a big light spot, and if I hold the magic wand at the light spot, and I start blinking away, the lights will follow the magic wand. It tracks it. So, it's actively tracking this bulb.

[Captions by Andrew Jackson] Captioning in different languages welcome. Please contact Destin if you can help.