I know.
This looks pretty freaky, but what you’re looking at is actually a monumental step forward
for medicine.
Researchers have now created an artificial womb that can successfully keep an extremely
premature fetus alive and developing normally.
A lamb fetus, that is.
The latest development in artificial placenta-based life support technology is an update to something
called the ‘ex vivo uterine environment’ or EVE.
It’s a bag that acts as an external womb, providing all the physical support an animal
would receive in utero.
The hope is that it could provide a more natural—and therefore also more successful—alternative
to the incubator, the standard clear plastic box used to hold babies in healthcare environments
like neonatal intensive care units.
See, a typical pregnancy lasts about 40 weeks, and any baby born before the 37 week mark
is considered premature.
Babies are technically able to survive outside the womb at about 21-24 weeks, but that’s
the extreme edge of viability, those babies are considered extremely premature.
And there’s a reason that one of the leading causes of death in newborns is being born
prematurely,—babies are really hard to keep alive outside the womb before a certain stage
in their development.
Even with the advances in healthcare we’ve seen throughout the last several decades,
like artificial airways and better ways to administer IV fluids to infants, infant mortality
for babies born before 28 weeks remains as high as 50%.
And for babies born on or before the edge of viability, which is about 24 weeks gestation,
mortality after premature birth is even higher.
Those who do survive premature birth are likely to still suffer from life-long disabilities
or chronic health conditions as a result of stunted organ development, so it makes sense
that we’re looking for a better way to keep babies alive and healthier when really, they
should still be in the womb.
One of the main barriers to a successful artificial womb, which has been the subject of study
for over 50 years, is that babies in utero are surrounded by amniotic fluid.
That’s why their lungs don’t work properly before 37 weeks, and instead of breathing,
they benefit from a complex shared circulatory system—they’re attached by their umbilical
cord and the placenta to their mother, whose own heart function keeps blood flowing between
the two, keeping the fetus oxygenated and taking carbon dioxide away.
Which is why helping premature babies ‘breathe’ outside the womb is such a struggle.
Existing pumps that keep gases flowing through the baby’s body present the problem of damaging
its heart—one of the many challenges in healthcare for premature babies.
So successful artificial wombs, like EVE, take inspiration from nature—they look like
a transparent, pillow-shaped plastic bag, filled with sterile artificial amniotic fluid
that gets cycled out, gets filtered, and gets cycled back in.
It relies on a novel, gentle oxygenator that uses just the fetal heartbeat to create successful
circulation without causing any damage.
The fetus receives essential amino acids via IV to replace the nutrients that would normally
be provided by the mother’s body, and antibiotics, also via IV, to protect it from infection
the way its mother’s immune system would.
Basically: we’ve discovered that there’s no beating the original, so we have to design
something that’s as close as possible.
A team in 2017 kept premature lamb fetuses alive and developing normally for up to four
weeks in an artificial womb, and one of the lambs that was not euthanized for further
study was instead bottle-raised, and is still alive, over a year after emerging from the
bag!
And in 2019 a joint research team between the University of Western Australia and Tohoku
University Hospital in Japan successfully kept extremely pre-term lamb fetuses—at
the equivalent of 24 weeks of human gestation—alive for an unprecedented 120 hours.
The lambs even continued to develop wool, just as they would have normally in utero.
You may be wondering why scientists are using lamb fetuses.
Sheep are a commonly-used model organism when studying prenatal development because they
go through many of the same processes in the womb as human babies, but they also grow faster
than the typical nine months, so we can study the same stages and mechanisms of development,
but at a slightly faster pace.
If this artificial womb stuff is sounding science fiction-y to you, it’s important
to remember that we shouldn’t get ahead of ourselves: I mean for starters this artificial
womb has only been tested so far on sheep, and only on already developing fetuses.
To grow a whole animal from scratch—that is, from an embryo—is an entirely different
story and something we’re quite far off from achieving.
But hopefully, this technology isn’t too far away from being implemented with premature
human babies, improving outcomes for preemies and their families all over the world.
We have a brand new series that we're stoked to share with you that's all about what goes
on in your body when you get sick.
And it’s called...well...Sick.
Beyond treatments and symptoms, we're curious about how exactly viruses, parasites, and
other invaders wreak havoc on our health.
Check out our first episode on Lyme disease and make sure to subscribe to get all your
science news.
Thanks for watching.