Forecasting the Revolution in Human Reproduction
A new book suggests that within just 20 to 40 years, most human reproduction will take place in the lab, rather than the bedroom.
Hank Greely, a Stanford professor who teaches law and genetics, writes about this potential brave new world in, “The End of Sex and the Future of Human Reproduction.”
While the book title refers to the “end of sex,” Greely is not predicting the end of human sexuality.
“I think that we will continue to have whatever we and Bill Clinton define as sex enthusiastically for a long time, but I don’t think we’re going to use it to make babies nearly as often,” Greely explains. “My guess is that in 20 to 40 years, most people in countries with good health systems will conceive their babies in clinics so they can do whole genome sequencing on about a hundred embryos and pick the embryo they like best.”
This is different from so-called designer babies, Greely says. “What I’m talking about is embryo selection. Two people get together and they make embryos. The embryos can only have whatever those two people bring to the plate. If they’re both blue-eyed, they’re not going to get a brown-eyed baby. If they’re both blood type O, they’re not going to get a blood type A baby.”
With designer embryos, on the other hand, one could, in theory, change the actual genes and change the genetic variation, so that people who were blood type O could have a blood type A baby, he says.
What Greely describes is based on the discovery of induced pluripotent stem cells (iPSCs), for which Shinya Yamanaka and John B. Gurdon won the 2012 Nobel Prize. iSPCs are cells that are reprogammed to become immature stem cells capable of developing into any type of tissue in the body.
iPSC research has generated great excitement in the scientific community and a lot of money and effort is going into it, Greely says. But it’s not going into it for reproductive purposes. “It’s going into it for nerve cells and pancreas cells and other cells for medical purposes — but as we learn more about deriving specific cell types from these iPSCs, we’re going to make eggs and sperm. … It’s just a matter of time.”
Making eggs this way is focused mainly on eliminating the need for egg harvesting, which is expensive, unpleasant and risky, Greely says. “Sperm harvest has not been as big a problem. But when you do a harvest for IVF, you get somewhere between zero and 25 eggs, Usually about 10 or 12. When you make them from skin cells, you could make hundreds of thousands, potentially millions.”
One hundred embryos seems a more manageable number to work with, Greely says. Each of those 100 embryos would have a combination of the genes from the parents, with different traits and possibility of diseases. Through analyzing the genetics of those embryos, doctors would be able to give parents a choice of good news and bad news. The prospective parents would then face the hard task of trying to weigh all the pluses and minuses.
“I think parents would be asked, ‘What do you want to know,’” Greely predicts. “‘We can tell you about the really nasty early genetic diseases that affect one to two percent of births; we can tell you about risk factors for later diseases like breast cancer, colon cancer, Alzheimer’s disease; we can tell you about hair color, skin color, nose shape, early white hair and things like that; we can tell you a little bit about behaviors. … What do you want to know? We’ll tell you and then you tell us which embryos you want to move into a womb to try to make a baby.’”
Among the many ethical issues Greely raises in the book is, what’s to prevent someone from getting some skin cells from a celebrity or a movie star and making a baby from them? You just happen to shake hands and rub off some skin cells, so you turn them into an egg and have their baby.
“I think we will need laws against inadvertent parenthood,” Greely says. “Right now, you’d have to steal somebody’s eggs or sperm, and that’s tricky. But stealing cells from somebody? Any discarded Coke can is going to have some cells on it. The whole issue of being able to make gametes from cells is going to bring up some things that will be surprising, and some I’m sure I haven’t thought of.”
Read an except from Greely’s book here.
Hank Greely is a professor of law who teaches law and genetics at Stanford University in Stanford, California. He’s the author of The End of Sex and the Future of Human Reproduction (Harvard University Press, 2016).
Read an excerpt from The End of Sex.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. We’ve been talking about radical ideas and ideas in using the body’s cells and using it to cure. But what if you could use parts of your body to actually choose. I have an idea, for example.
Here’s the idea. What if you could take your skin cells and turn them into viable human cells, human eggs? You know, the kinds that women carry around in their ovaries. Scientists have already done that procedure in mice, turning skin cells into eggs and into sperm. And guess what, they raised baby mice from those stem cell derived cells.
So how long before that’s the norm for human reproduction? Given the rate of technological advancement, well, my guest wagers it’s going to be just 20 to 40 years from now. He writes about the brave new world of human reproduction in his new book, The End of Sex and the Future of Human Reproduction. And being a lawyer and an ethicist, he raises a lot of dicey questions for that future world too.
Like if you could choose to spare your child a debilitating genetic disease by screening, let’s say, 100 test tube embryos first, would you do that? What if you also had the option to choose other traits, like hair color versus musical ability, and trade off something else? And more importantly, who has access to the technology and who doesn’t? Will you have to be a rich person? Will everybody have access to this?
What do you think? A dangerous idea, natural progression, stuff you’d like to be part of? Our number 844-724-8255. 844-SCI-TALK. Hank Greely IS the author of The End of Sex and the Future of Human Reproduction, professor of law who teaches law and genetics at Stanford University. Welcome back to Science Friday, Hank.
HANK GREELY: Thanks very much, Ira.
IRA FLATOW: When you say the end of sex, you’re just not talking about sex.
HANK GREELY: Yeah, I think that we will continue to have whatever we and Bill Clinton define as sex enthusiastically for a long time. But I don’t think we’re going to use it to make babies nearly as often. My guess is that in 20 to 40 years, most people in countries with good health systems will conceive their babies in clinics so they can do whole genome sequencing on about 100 embryos and pick the embryo they like best.
IRA FLATOW: So you would be able to take the skin cells from anybody and turn them into embryos and sperm?
HANK GREELY: Well, turn them into eggs and sperm–
IRA FLATOW: I’m sorry, eggs and sperm.
HANK GREELY: –and then combine those to make embryos, yeah. I think that’s likely to happen. This process of induced pluripotent stem cells, for which Shinya Yamanaka won the Nobel Prize in almost record time, is so exciting, and so much money and effort is going into it. It’s not going into it for reproductive purposes, it’s going into it for nerve cells, and pancreas cells, and other cells for medical purposes.
But as we learn more about deriving specific cell types from these IPSCs, these Induced Pluripotent Stem Cells, we’re going to make eggs and sperm. And the first steps have already been taken toward that in humans in terms of making the primordial cells that ultimately become eggs and sperm. No one has tried to make eggs and sperm for humans from these yet, as far as I know. But I think that’s just a matter of time.
IRA FLATOW: So then you would wind up with what, a few dozen embryos from the cells from your skin? And you would choose– you’d choose which embryos you’d want to keep?
HANK GREELY: Yeah, I think so. Although an interesting point about making eggs this way– the issue is mainly eliminating egg harvest, which is expensive, unpleasant, and risky. Sperm harvest has not been as big a problem.
But when you do egg harvest for IVF, you get somewhere between 0 and 25 eggs, usually about 10 or 12. When you make them from skin cells, how many eggs do you get? How many do you want? You could make hundreds, thousands, potentially millions. I think roughly 100 embryos, do whole genome sequencing on each of those embryos, and then the prospective parents have the real hard time of trying to weigh all the pluses and minuses in those 100 embryos.
IRA FLATOW: So each of those 100 embryos would have a combination of the genes from the parents, with different traits and possibility of diseases. And you would, through analyzing the genetics of those, be able to give them a choice of good news and bad news.
HANK GREELY: Right. I think parents would be asked, what do you want to know? We can tell you about the really nasty early genetic diseases that affect 1% to 2% of births. We can tell you about risk factors for later diseases, like breast cancer, colon cancer, Alzheimer’s disease. We can tell you about hair color, skin color, nose shape, early white hair, things like that.
We can tell you a little bit about behaviors. Maybe 12% chance of being in the top 10% in math ability. And the last and easiest category, we can tell you boy or girl. What do you want to know? We’ll tell you, and then you tell us which embryos you want to move into a womb to try to make a baby.
IRA FLATOW: This also means that gay or lesbian couples could have a baby with their own genetic material, without looking for a donor egg or sperm, doesn’t it?
HANK GREELY: Yeah, that takes one more step, but I think it’s a plausible one. And not just me. Other people I’ve talked to in the field think it’s a plausible one to take skin cells from a man and turn them into eggs, and skin cells from a woman and turn them into sperm, or at least things that are good enough to be used as sperm. They don’t have to be fully functional, because we can take sperm and inject them directly into the egg.
You don’t necessarily have to make sperm that can swim as far as they do the old fashioned way. The trickiest part would be making sperm from women that could give rise to boys. You’d have to add a Y chromosome. 20 to 40 years from now, I think that’s plausible. But we’ll have to wait and see.
IRA FLATOW: Well, what would be the difference between what you’re suggesting and so-called designer babies?
HANK GREELY: So what I’m talking about is really embryo selection. Two people get together. They make embryos. The embryos can only have whatever those two people bring to the plate. So if they’re both blue-eyed, they’re not going to get a brown-eyed baby. If they’re both blood type O, they’re not going to get a blood type A baby.
With designer embryos, you could, in theory, change the genes, change the genetic variation, so that two people who were blood type O could have a blood type A baby. When I started writing this book, I dismissed that as decades away. CRISPR-Cas9 caused me to rewrite a significant chunk of the book, because I now think it’s closer than I had expected. But it adds additional risks. And I think it’s still a decade or two farther away than what I called easy PGD.
IRA FLATOW: You know, the cynic part of me always thinks of things that could happen. And when I was reading about this, I said, what’s to prevent me from getting some skin cells from a celebrity, movie stars? Taking them– they drink out of a cup of coffee or water or something like that, and you take the cup. Or you just happen to shake hands and you scrub off some skin cells, then take it back. And then now I’m going to have their baby. You know, I can turn that into an egg.
HANK GREELY: So you’ll be pleased to know that you’re not the only cynical person out there. This issue occurred to me. And I talk about it some. I think we will need laws against inadvertent parenthood.
Right now, you’d have to steal somebody’s eggs or sperm, and that’s tricky. But stealing cells from somebody, any discarded Coke can is going to have some cells on it. But that’s just– the whole issue of being able to make gametes from cells is going to try out some things that will be surprising. Some I’m sure I haven’t thought of, but among other things, you could make eggs and sperm from people who were dead, or at least from well preserved cells from people who were dead. That makes– we’ve had posthumous parenthood, posthumous fatherhood for a while, but this opens some even wilder possibilities.
IRA FLATOW: We’re not talking about cloning dead people, so that people hear this going by, and they’re thinking we’re cloning. We’re not cloning dead people. We’re just–
HANK GREELY: Right.
IRA FLATOW: –taking the cells from them and making another person with two different people.
HANK GREELY: Right. You’re making eggs or sperm from the dead person and combining it with eggs or sperm from someone else, living or dead. You’d need the cells to be carefully preserved in order– or to be very fresh in order for that to happen, though.
IRA FLATOW: Let me give you a “for example.” What about someone like Stephen Hawking? He could have kids. He has kids, but could you then have other kids and screen out, let’s say, the ALS genes, sparing the disease? Could you notice that in the– through your gene screen in the embryos, and say, oh, that’s not a good one, but this one doesn’t have it?
HANK GREELY: Yeah. So the good news and the bad news of whole genome sequencing is it can tell you everything that genetics can tell us about those embryos. That’s the good news. The bad news is there’s an awful lot that it can’t tell us.
Most ALS doesn’t seem to have a genetic root. I don’t know about Hawking’s version of it. I think geneticists understand better than the lay population, genes aren’t as powerful as people often think that they are. This couldn’t guarantee you a healthy baby, but it could guarantee you 4,000 to 6,000 diseases that your baby wouldn’t have.
So if Hawking’s ALS is of genetic origin, and there are some people who have a heavily familial form of ALS, you could screen embryos made from his cells to make sure that those embryos didn’t inherit his ALS. Would that change their brilliance or change whatever drove them to be as great as Hawking is? Maybe. Hard to know.
IRA FLATOW: You saying that we’re talking 20 or 40 years from now. And we’d certainly, I would think, know that kind of information. Not how smart you are, but whether there’s a genetic connection or not, more closely between the genes and diseases. Let me go to the phone– I’m sorry, you want to jump in?
HANK GREELY: Yeah. I just– we certainly should know more. How much we’ll understand about just common diseases or diseases that aren’t obviously genetic remains to be seen.
IRA FLATOW: Let’s go to Aaron in Bethesda. Welcome to Science Friday.
AARON: Hi there. Just had a quick question. So I assume that technology for gene editing and sort of screening embryos and things of that nature wouldn’t be that cheap. And so my concern is that we end up having a genetics class divide. And I was wondering what your guest could say about that, whether or not that would happen, or sort of the realities of that situation?
IRA FLATOW: Good question.
HANK GREELY: Happy to. I think it’s Chapter 17 or so. Even today, trying to figure out what a medical procedure costs makes you crazy. And trying to predict it 20 to 40 years out is really insane. But I do it in the book anyway.
My ballpark guess is roughly $10,000 per baby. I think it’s actually likely to be less than that in today’s dollars, but somewhere around there. I actually think this will be made available free in countries that have good health systems, because at $10,000 a baby, 100 babies costs the system a million dollars. 1% to 2% of babies born naturally are going to have– conceived naturally– are going to have some serious genetic disease.
How many of those one or two do you have to– how many births of those 1% or 2% do you have to avoid to save a million dollars? About 0.2. I think this is going to be cost effective enough that both for egalitarian reasons, but also for sort of hard-nosed financial reasons, it’s going to be made available on a subsidized basis to every prospective parent.
If I turn out to be wrong about that, I’d still argue strongly it should be made available to everyone. It’s not going to make super babies. We don’t know how to make super babies. But to add another 10% to 15% better health to the children of the rich but not the children of the poor would be a bad thing. And it’s something we need to worry about and try to avoid.
IRA FLATOW: Do you think the FDA would approve something like this, making sperm and eggs from stem cells?
HANK GREELY: If it’s proven safe and effective, I think the FDA would have no choice but to approve it. The FDA isn’t a morals police. It’s a scientific agency focusing on safety and efficacy. But I think the really interesting thing, Ira, is I think the FDA will approve this not as part of genetic testing, but approve it first as a fertility aid for the millions of people in America who can’t have kids, can’t have genetic kids, because they don’t make eggs or sperm.
Early illness, an accident, a birth defect, or in the case of many women, just too old. It means that there are a lot of people out there who would like to have genetic children who don’t make eggs and sperm. This is likely, I think, to be approved first to treat those fertility problems. But in the United States, once the FDA approves a drug or a biological product for one purpose, a doctor is allowed to use it for any other purpose he or she sees fit.
IRA FLATOW: I’m Ira Flatow. This is Science Friday from PRI, Public Radio International. Talking with Hank Greely, author of The End of Sex and the Future of Human Reproduction. Really a terrific book, if for nothing else, that it teaches you the ABCs of all the genetics in there right at the beginning. And it really makes you think about the future.
HANK GREELY: I’m glad you said that. I’m really proud of that first section where I try to explain genetics, stem cells, reproduction to laypeople. I’m a lay person myself. I’m a lawyer whose last bio class was in 10th grade. And I hope people will read that part of the book too. I came to a love of biology late in my life. And it’s amazing stuff. And I hope other people will be similarly inspired.
IRA FLATOW: Do you think, though, that there are a lot of people– I mean, there are still people around who don’t want to know the sex of their children. They don’t want to even see ultrasound. Do you think there might be some pushback on this, and even 20 or 40 years from now?
HANK GREELY: Oh sure. I don’t think everyone will do this. At least if they’re in a country that gives them that choice. And that’s another worry. I think there will always be people who, for religious reasons, or philosophical reasons, or romantic reasons, or just because they’re teenagers and getting pregnant in the backseat of the car is what they do, I think there will always be people who won’t use this.
I think those numbers will decline as people see that it doesn’t produce three-headed monsters, and see that avoiding that 1% to 2% chance of having a seriously ill baby has a lot of value. I think that is– in the perhaps bad parlance of Silicon Valley– that’s the killer app for this. Avoiding that 1% to 2% chance of having a child who has an early and severe genetic disease will be very attractive to people, I think.
IRA FLATOW: And all those extra embryos, those hundreds of extra embryos, what happens to them?
HANK GREELY: Presumably they are destroyed, which means I think the Vatican City is not likely to legalize this procedure anytime soon.
IRA FLATOW: But they are– go ahead.
HANK GREELY: What that means for a more right to life states in the United States is an interesting question. We have a very strong right to life movement in the US, but we also have almost completely unregulated IVF. So I think right to life people like healthy babies. They don’t necessarily like destroying embryos. But my guess is the US will not ban this kind of technology, even if it does, if Mississippi does but Georgia doesn’t, I can imagine reproductive tourism being quite common.
IRA FLATOW: We’ve run out of time. I want to thank you, Hank, for writing the book and for coming on Science Friday.
HANK GREELY: Oh, thanks for having me. It’s always great.
IRA FLATOW: Terrific book. Hank Greely, author of The End of Sex and the Future of Human Reproduction. Hank is a professor of law who teaches law and genetics at Stanford University in California.