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.
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Thanks for watching.
