Heather Radke
Appearances
Radiolab
Everybody's Got One
As the mother's blood starts rushing into the placenta, the fetus just starts growing and growing. It's the size of a grapefruit by week 15, a pineapple by 24, a watermelon by 36.
Radiolab
Everybody's Got One
And all the while, the placenta is gobbling up more and more of the mother's blood.
Radiolab
Everybody's Got One
Preeclampsia is very, very scary. And it's basically when the mother's blood pressure spikes so high that she can actually die. Whoa. And it's really serious. It's one of the leading causes of maternal death. And I think it's easy to sort of think, like, high blood pressure, you know, not such a big deal.
Radiolab
Everybody's Got One
But it's actually the placenta, you know, sucking so much blood out of the mother's body that she can't. continue to survive.
Radiolab
Everybody's Got One
But the placenta is still in there. And so the placenta actually also kind of has to be born. I'm getting the sense that the placenta may be underneath this blue cover. Is that right?
Radiolab
Everybody's Got One
So we didn't actually see anyone give birth to a placenta. But Harvey did show us one in his lab.
Radiolab
Everybody's Got One
So I'm going to pick it up and see how heavy it is. So I grabbed the placenta. It's kind of heavy. Like what?
Radiolab
Everybody's Got One
About as wide as a volleyball. It's really weird. Okay, first of all, it's cold. Maybe slimy is the word. And it's got a lot of texture when you're in the beefy part. You can feel what I imagine are the veins. And it has like, it's not all one texture. It's like hard in spots and soft in spots. It feels sort of like crazy.
Radiolab
Everybody's Got One
And what's kind of cool is it leaves no scar. It's like one of the only things like this in the body, maybe the only thing like this, where something sort of gets sheared off and there's no, like no mark remains there.
Radiolab
Everybody's Got One
This is Tina Delisle. She's a professor of history at the University of Minnesota Twin Cities, and she's writing a book about the placenta. Indigenous people were understanding the placenta for a long time. She explained to us that this dawning we were having, that the placenta is kind of like a parent.
Radiolab
Everybody's Got One
Well, I think I can... You take it. Okay. I was thinking about getting pregnant, and I started to do a bunch of research about And, you know, pregnancy is this thing, at least for me, where I was like, I know about that. You know, I took like 14 years of sex ed in my public high school.
Radiolab
Everybody's Got One
It's something that a lot of people had already been thinking about the placenta for a really long time.
Radiolab
Everybody's Got One
Okay, so you're saying that the placenta isn't just looking after the well-being of the child when it's in the womb, but also into adulthood? Yes.
Radiolab
Everybody's Got One
But things have changed some since Tina gave birth in 2006. In states like Hawaii and Texas and Oregon, now you can legally take your baby's placenta home with you.
Radiolab
Everybody's Got One
But I'll just say the more I learn about it, the more I realize how little I know and maybe like how little anyone knows about pregnancy. Yeah. And one of the very first things I discovered was that when you're pregnant, you don't just grow a baby. You grow an entirely new organ.
Radiolab
Everybody's Got One
Your whole life, you've got your heart, your lungs, your bone, your skin, your eyes, etc. So this is the main hospital. But then all of a sudden during pregnancy...
Radiolab
Everybody's Got One
I had heard of the placenta before, but I really didn't know anything about it.
Radiolab
Everybody's Got One
I think I thought a thing a lot of people think, which is that the baby grows inside the placenta.
Radiolab
Everybody's Got One
So it's actually grown by the fetus, which means that every single one of us has had a placenta.
Radiolab
Everybody's Got One
I'm interested in how you got interested in the placenta. Presumably it wasn't because you got pregnant. Serendipity.
Radiolab
Everybody's Got One
Eventually he figured out that what he was looking at were stem cells, placental stem cells. And over the next few decades, he and a bunch of other scientists would start to piece together the story of the placenta.
Radiolab
Everybody's Got One
So before we start, we just want to say a note on the word mother. Not everyone who gets pregnant or has a baby identifies as a mother, but it's a word a lot of people use when talking about pregnancy, including some of our sources. And so we're using it in addition to more inclusive language like pregnant person and parent. Got it.
Radiolab
Everybody's Got One
By the time it gets to about 32... The cluster of cells sort of forms into two layers.
Radiolab
Everybody's Got One
So from the very first few days of pregnancy, these placental cells are wrapped around what's going to become the embryo, like a little blanket. And as Harvey explained all this to us, and he walked us deeper into the story of the placenta, we started to see that pregnancy isn't a peaceful nursery rhyme kind of a story about a pregnant person nurturing a fetus until it becomes a cute little baby.
Radiolab
Everybody's Got One
It's actually more like a struggle and not like a calm college debate. It's like a cage match, like a knock-down, drag-out boxing match, or a tiny war, maybe even. On one side is the pregnant person, and on the other side is the fetus. And in the middle, or maybe not actually in the middle, more like actually in the corner, rubbing the shoulders of the fetus, is the placenta.
Radiolab
Everybody's Got One
But... Before the mother's body even has a chance to attack the embryo, the placenta blanket hides it.
Radiolab
Everybody's Got One
Mom's still at the bar. She sure is. Okay, so for the first week or so of the pregnancy, the placenta is pretty much just hiding the embryo from the mother. But then...
Radiolab
Everybody's Got One
The embryo gets hungry. And the placenta's like, I gotta feed this thing. And this is when the battle lines really start to get drawn. Because essentially this war between the placenta and the pregnant person is a war that's about food. The placenta, Harvey says, has one mission.
Radiolab
Everybody's Got One
So basically the story we told then is that before placentas, all animals that would become mammals laid eggs. And an egg is a special little thing. It's a self-contained little package where the fetus has everything it needs to eat until it's ready to hatch and all of its waste products stay inside the egg and nothing comes in and nothing goes out until the animal is ready to leave its egg.
Radiolab
Everybody's Got One
an ancient proto-mammal and changed its DNA so that eventually, many generations later, the eggshell transformed from a hard shell that exists outside the body to a sort of permeable layer that exists inside the body, which then becomes the placenta. And this was a huge advantage because it made it possible for the blood of the mother to actually feed the fetus.
Radiolab
Everybody's Got One
So it could get tons more nutrients. It wasn't limited to just like whatever yolk was inside the egg from the beginning.
Radiolab
Everybody's Got One
Geneticist Melissa Wilson again. That's mind-blowing. Because it made it possible to actually make a baby with a big, giant brain, like a human being or a dolphin. And that was great. But it also had this downside.
Radiolab
Everybody's Got One
Okay, and this is how we've ended up four weeks into what's basically a war between the mother and the placenta, with the placenta trying to suck blood out of the mother, and the mother basically trying to box it out. And this fight...