Name: 科学者たちは袋の中で子羊を育てた...何を待っているの？ (Scientists Grew a Lamb in a Bag... Wait What?)
Uploaded: 2021-01-14T09:58:55.000Z
Duration: 5 min 11 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

This looks pretty freaky, but what you’re looking at is actually a monumental step forward

Researchers have now created an artificial womb that can successfully keep an extremely

premature fetus alive and developing normally.

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

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

See, a typical pregnancy lasts about 40 weeks, and any baby born before the 37 week mark

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

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

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

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

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

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,

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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