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  • I know.

  • This looks pretty freaky, but what youre 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 theex vivo uterine environmentor 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 naturaland therefore also more successfulalternative

  • 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 weve 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 were 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 systemtheyre 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 babiesbreatheoutside the womb is such a struggle.

  • Existing pumps that keep gases flowing through the baby’s body present the problem of damaging

  • its heartone of the many challenges in healthcare for premature babies.

  • So successful artificial wombs, like EVE, take inspiration from naturethey 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: weve 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 fetusesat

  • the equivalent of 24 weeks of human gestationalive 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 scratchthat is, from an embryois an entirely different

  • story and something were 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.

I know.

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科學家在袋子裡養了一隻羊...等等什麼? (Scientists Grew a Lamb in a Bag... Wait What?)

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    林宜悉 發佈於 2021 年 01 月 14 日
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