This article is from The Checkup, MIT Technology Review's weekly biotech newsletter. To receive it in your inbox every Thursday, sign up here.
Hello, and welcome back to the Checkup!
This week I found myself back in the classroom, sitting on a small plastic chair and carefully noting down what the teacher told me. It was my first parent’s evening. By coincidence, just a few days earlier I had been listening to scientists and ethicists at a meeting in Amsterdam discuss what it means to be a parent.
It’s a huge question—and one that is changing in light of new reproductive technologies that are transforming the way we make families. We tend to think of these technologies with the baby in mind: How likely are they to result in a baby? Do they have any impact on the baby’s health or well-being?
But parenthood is the goal of most people seeking these treatments. As Heather Draper, a bioethicist at the University of Warwick, put it at the Amsterdam meeting: “Arguably the main purpose of assisted conception is not the creation of a child, but the creation of parents.”
Advances in reproductive technologies are forcing us to reconsider what it means to be a parent—even at the genetic level. IVF allows would-be parents to use eggs and sperm donated by others, who may or may not have a role in the life of the resulting child. But it’s not just IVF. Technologies that result in babies with three genetic parents are already in use. And others that enable four or more genetic parents could be available in the near future.
This kind of progress inevitably raises vital questions. What is it about a genetic contribution that may or may not make a person a parent? Is there an ideal number of parents a child can have? And, when we come down to it, do genetics even really matter at all?
The question came to the fore around six years ago, when a doctor in New York revealed that he had used a new technology that led to the birth of a “three-parent baby.” The baby’s mother carried genes for a potentially fatal disease in her mitochondria—components of the cell that provide energy. To get around this, the doctor and his colleagues used mitochondrial DNA from a donor, as well as the woman’s egg and her partner’s sperm.
The resulting baby technically had three genetic parents—even though the donated mitochondrial DNA made up only a tiny fraction of his total DNA. Some scientists said this meant that the term “three-parent baby” didn’t really apply. But this implies that there is some cutoff—what percentage of a baby’s DNA do you need to contribute to be considered a parent?
The technique is used at a handful of clinics today, mostly to help parents avoid passing mitochondrial diseases on to their children. For most of these cases, the person contributing mitochondrial DNA might simply be an unrelated donor who will have no further contact with the baby.
But for others, mitochondrial DNA might represent an important genetic link to a child. If two women want to have a baby together, for example, they might use one of their eggs and sperm from a donor. In those cases, the baby is genetically related to only one of the women. Including the mitochondrial DNA of the other woman would offer her a genetic link to the baby too, albeit a much smaller one.
Four or more parents?
There are other technologies on the horizon that might enable even more people to share genetic parenthood of a baby. Scientists are working hard to turn human skin and blood cells into egg and sperm cells in the lab. They’ve already done this in mice. If they can manage to do it in people, the possibilities for biological parenthood expand even further.
The first application would be to enable same-sex couples to have genetically related children. You could, for example, turn the skin of one man into an egg cell, and fertilize it with the sperm of his partner to create an embryo.
But you could also use the same technology to create another sperm or egg cell from that embryo. In theory, you could do this with sex cells from two couples, ultimately creating an embryo that has four genetic contributors.
Things get even more confusing here, because the four adults would actually be grandparents, and the embryos created in the middle step would be the baby’s parents. Some scientists have said that, technically, these babies would be born orphans. But the way others see it, they’d have four parents.
Of course, a genetic connection is not really what makes someone a parent. A parent is not the supplier of DNA—it is the person who takes care of the child and provides an environment for them to flourish.
You don’t need to be a child’s biological parent to do this. That’s obvious, but it’s also backed up by data collected by Vasanti Jadva, at University College London. Jadva and her colleagues have followed the progress of 223 children born around 2000. While 80 of the children were conceived in the typical way, 51 resulted from egg donation, 50 were conceived with sperm donation, and 42 were gestated by a surrogate. But there was no real difference in the children’s well-being throughout their childhoods.
By the age of two, the children that resulted from donors and surrogates showed no difference in social, emotional, or cognitive development. If anything, they appeared to have more positive relationships with their parents than those conceived in the typical way.
And they weren’t particularly bothered about the circumstances of their conception, either. By the time they were 21 years old, most of them weren’t concerned about having been born through egg or sperm donation or surrogacy, Jadva said at the meeting in Amsterdam.
Draper said she “doesn’t get” the importance some people seem to place on genetic parenthood. “An obsession with biological connectedness tends to make non-biological parents be seen as second-best parents, and I think that’s actually quite offensive,” she said.
I’ve been thinking over these words since I heard them. For the most part, I’m inclined to agree—fulfilling your responsibilities as a parent has nothing to do with how much DNA you share with your child. But we also need to remember that biological parenthood is important for a lot of people. And if it’s technically possible, why shouldn’t we all have the option, no matter our gender, sexual orientation, or health status?
It's a tricky one. In the meantime, I’ll be focusing on fulfilling my own parental duties—whether that means catching up with homework, trying to limit processed foods and screen time, or just finding more time for cuddles. My daughter’s teacher told me that she’s already showing an interest in science, which I’ll take as a win for now.
There’s lots more to read from the Tech Review archive:
I recently took an in-depth look at the race to make human egg and sperm cells in the lab …
… which followed on from a piece my colleague Antonio Regalado wrote last year, when he covered the work of Conception, one of the biotech companies attempting to do just that.
In 2017, a year after the birth of the “three-parent baby,” Emily Mullin described how the doctor behind the case was planning to use the same approach to rejuvenate eggs.
Other scientists are working on ways to mature the eggs of transgender men in the lab, which could help them have genetically related children …
… and the “three-parent” approach could be useful here too.
From around the web
Researchers at Boston University have been generating new versions of the coronavirus in the lab. University representatives said the new virus was no more dangerous than the “original” found in Wuhan, but it still killed 80% of infected mice. (STAT)
Is aging a disease? The debate rages on. (MIT Technology Review)
Three hundred thousand chickens are due to be culled in the Netherlands after a highly infectious strain of bird flu was found on a farm. Almost 6 million birds have already been culled in the country in the last year. (Reuters)
Public schools in Texas are about to start sending children home with DNA kits. The idea is to provide parents with information they might find useful in an emergency—but the move might just make families more anxious about school shootings. (Motherboard)
Biotechnology and health
Scientists are finding signals of long covid in blood. They could lead to new treatments.
Faults in a certain part of the immune system might be at the root of some long covid cases, new research suggests.
Gene editing had a banner year in 2023
This year, gene editing finally started living up to its potential
The first gene-editing treatment: 10 Breakthrough Technologies 2024
Sickle-cell disease is the first illness to be beaten by CRISPR, but the new treatment comes with an expected price tag of $2 to $3 million.
This baby with a head camera helped teach an AI how kids learn language
A neural network trained on the experiences of a single young child managed to learn one of the core components of language: how to match words to the objects they represent.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.