An artificial womb could build a bridge to health for premature babies

TORONTO — A surgical team scurries around a pregnant female pig lying unconscious on an operating table. They're about to take part in an experiment that could help provide a new option to help premature babies survive.

"The ultimate goal of today is to transition a fetus onto that artificial womb," says Dr. Christoph Haller, motioning to a clear rectangular plastic sack with tubes running in and out of it.

"We're transitioning it into an artificial environment that allows the fetus to still maintain its regular physiology," says Haller, a pediatric heart surgeon at The Hospital for Sick Children.

Today, it's a pig fetus that Haller and his colleagues will be using to test their artificial womb. But their hope is that someday, technology like this will help humans survive extremely premature birth and avoid serious complications, such as blindness and permanent damage to lungs and brains.

"We're basically trying to find a new concept on how to preserve fetuses to allow them to mature more physiologically compared to the regular preterm. That would be the target — to treat extreme premature babies," says Haller, who's also an assistant professor of surgery at the University of Toronto. "This would hopefully be a big deal — a game changer."

NPR was granted exclusive access to watch Haller's team test their artificial womb.

Research like this is generating enormous excitement among doctors who treat babies who are born prematurely, a major cause of infant mortality and disabilities. But the prospect of an artificial womb is prompting a long list of questions.

"I think it's a really promising and fascinating technology," says Dr. Mark Mercurio, a professor of pediatrics who directs the program for biomedical ethics at the Yale School of Medicine. "But certainly it raises ethical concerns and questions that need to be addressed."

The procedure remains highly experimental

A metal tray next to the pig's belly is covered with blue paper. Haller's team just drew a picture of a pig's face on the paper surrounded by the words "Oink. Oink. Oink." and "We ❤ you." Then they laid out the artificial womb on top of it. Some call this kind of contraption a "biobag."

Next, the surgical team arranges equipment and examines the 10 fetuses in the sow's womb with an ultrasound. Haller uses a clipper to make some last-minute adjustments to tubing he'll stitch into the fetal pig's umbilical cord.

The tubes will supply the fetus's blood with oxygen, remove carbon dioxide from the blood and supply nutrition and medicine.

"I'm MacGyvering stuff here to make things work," he says with a laugh.

Finally, everyone's ready to remove one of the fetuses.

"All right, I think we're going to get started," Haller says, prompting the team to gather tightly around the pig.

Wisps of smoke rise from the pig's belly as Haller makes an incision with an electric scalpel. An assistant suctions the area to keep it dry.

"So what you're looking at is basically the uterus. And then in here is the fetus. The head's somewhere here, where I have my hand. The rest of the body is still inside," he says.

After deciding which fetus looks best on the ultrasound, Haller makes another incision in the uterus and pulls out a bright pink fetal piglet. The fetus looks peaceful, like it's sleeping.

Once the fetus is completely out, Haller and his team quickly assess its health and cut the umbilical cord so they can transfer the animal into the artificial womb.

A "biobag" becomes the new womb

After gingerly sliding the fetus into the "biobag," Haller quickly attaches the three umbilical cord tubes. His colleagues fill the bag with a clear, warm liquid meant to mimic amniotic fluid and seal the artificial womb.

"It's going to be a bit of a rocky period now," Haller says.

The team carefully monitors the fetus's heart rate, blood pressure and other vital signs. Once it looks stable, the researchers surround the biobag with warmers.

"It's as close to a good transition as you can get I think," Haller says. "I'm excited as if it was a proper human surgery I would say — just because I want to get it right and I want to see the fetus doing well there."

This will go on for hours.

"You may see the fetus starting to have breathing-like movements. But that's what's in line with what's happening in utero too — as if they are training basically a bit. You may see that it kicks its legs," Haller says. "That's what we like to see because it signals a certain level of health."

An artificial womb could be a bridge to better health

If very premature babies can be safely sustained on a device like this for just two or three weeks, it could make all the difference between life and death or a life with severe disabilities and health problems or not, Haller says.

The Toronto group has seen blood clots and heart problems develop. So far, they've only been able to sustain a pig fetus for about a week.

But researchers at Children's Hospital of Philadelphia have safely sustained fetal sheep on a very similar device for four weeks, making the Toronto group and others optimistic the approach will eventually work.

"If this artificial womb technology could sustain a patient even for a period of weeks and get them to a later stage and a bigger size, that could potentially be quite a dramatic change in our field," says Dr. Mike Seed, an associate professor of pediatrics at the University of Toronto who is working with Haller.

Scientific progress prompts ethical concerns

But the possibility of an artificial womb is also raising many questions. When might it be safe to try an artificial womb for a human? Which preterm babies would be the right candidates? What should they be called? Fetuses? Babies?

"It matters in terms of how we assign moral status to individuals," says Mercurio, the Yale bioethicist. "How much their interests — how much their welfare — should count. And what one can and cannot do for them or to them."

But Mercurio is optimistic those issues can be resolved, and the potential promise of the technology clearly warrants pursuing it.

The Food and Drug Administration held a workshop in September 2023 to discuss the latest scientific efforts to create an artificial womb, the ethical issues the technology raises, and what questions would have to be answered before allowing an artificial womb to be tested for humans.

"I am absolutely pro the technology because I think it has great potential to save babies," says Vardit Ravitsky, president and CEO of The Hastings Center, a bioethics think tank.

But there are particular issues raised by the current political and legal environment.

"My concern is that pregnant people will be forced to allow fetuses to be taken out of their bodies and put into an artificial womb rather than being allowed to terminate their pregnancies — basically, a new way of taking away abortion rights," Ravitsky says.

She also wonders: What if it becomes possible to use artificial wombs to gestate fetuses for an entire pregnancy, making natural pregnancy unnecessary?

"Science fiction writers have been playing with this notion for decades. It's not like we never thought about it. It's just different to think about it as a thought experiment and to think about it as something that's potentially around the corner," Ravitsky says. "The scenario of a complete use of artificial wombs could become pretty scary, pretty quickly."

But Haller and his colleagues say the darkest worries are unfounded.

"We've heard people fearing that this translates into women not having to go through a full pregnancy anymore — kind of more like a Matrix-style of dystopian future," Haller says.

"But it would be outrageous to assume that any artificial intervention in any way is better than nature. So if you're not running into problems in your pregnancy, I think there's a lot of evidence that you're better off being born as you should be from what nature intended," he says.

Haller and his colleagues, he says, are just trying to save babies.

"Every tool can be misused," he says. "Like AI — it has its benefits, but if it's not regulated adequately a lot of harm can arise from something like that as well."

Meanwhile, the fetal pig is settling into its new artificial womb.

"I think it looks pretty, pretty comfy and settled," Haller says. "It looks pretty, pretty happy in there. Yeah, it's good."

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