“Plastic Bag Womb” Keeps Premature Baby Lamb Alive

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Wednesday 26th April 2017

A lamb born premature has been kept alive and growing in a plastic artificial womb, in a breakthrough for medical science that could provide hope for human babies born prematurely.

The artificial womb, looking somewhat like a plastic bag, contains everything a foetus needs in order to keep developing, such as a blood supply rich in nutrients and a mixture that replicates the effect of amniotic fluid, which help protect and support the growing foetus.

A special machine, connected to the Lamb’s umbilical cord, provides a supply of oxygen and nutrients, while the lamb’s own heart pumps out the “used” blood before it is resupplied and returns to the body. The lambs stay in the “biobag” for four weeks and when their hearts and lungs have matured enough, they are released so they can start breathing air.

It is quite a sight to see the baby lambs in the bag, as they look comfortable, open their eyes, grow a woolly coat and develop in front of your very eyes. After the experiment period, some of the lambs were killed so brain analyses could be done to check the level of development, however others were bottle fed, and appeared to have developed normally.

The intention, explains Dr Emily Partridge, is to improve the care of babies on the edge of viability, and the lambs in question were the equivalent of 23-week old foetuses.

Currently any baby born before this time has nearly no chance of surviving; its vital organs haven’t developed enough to keep it alive. At 23 weeks, a baby has a 15% chance of surviving, which leaps up to 55% at 24 weeks and by 25 weeks is about 80%. So the biobag has the potentially vital purpose of improving a baby’s chance of living, although there are number of problems before such an idea could be translated to human babies.

The first is infection control, the big killer in premature births, and something that the biobag currently has major issues with. Along with this, developing a mix of nutrients and an amniotic fluid suitable for a baby is more difficult than with a lamb.

Then there is the issue of how parents of premature children may feel about the aesthetics of a child in a biobag, although Dr Marcus Davey has noted that the team envisage that the treatment would consist of a more traditional incubator with a baby inside the biobag.

While there are significant implications to consider before human babies could be testing, the concept is incredibly interesting. It should be stressed, and indeed the researchers stress this as well, that the aim of the artificial womb is not to replace mothers or extend the limits of viable birth ages, but more to support babies born prematurely, particularly given the known issues with incubators and ventilation care on the development of said baby’s lungs.

There is a lot of research that needs to be taken before this gets anywhere near a hospital but regardless it is fascinating to see where this progresses.