Scientists have been able to keep premature lambs alive for weeks using an artificial womb that looks like a plastic bag, providing a nutrient-rich blood supply and a protective sac of amniotic fluid, researchers reported.
Writing in the journal Nature Communications, researchers from Children's Hospital of Philadelphia believe the approach may one day help premature human babies have a better chance of survival. The researchers anticipate animal studies will be completed within two years, and if approved, the "biobag" wombs can be tested on human preemies within three to five years. In a video that accompanied the release of the study, Emily Partridge, a research fellow at the hospital, described being struck by the sight of the zipped-up lamb fetuses, "breathing, swallowing, swimming, dreaming" – all with "complete detachment from the placenta and from mom." Speaking with reporters Monday, the Philadelphia researchers emphasized they don’t intend to expand the bounds of life before the 23rd gestational week because before that point, fetuses are too fragile even for the artificial wombs, The Atlantic reports.
In the study, researchers used eight lamb fetuses that were 105 to 115 days old—a level of development comparable to a 23-week-old human fetus. As they floated, the lambs’ brains and organs developed normally. The pinkish creatures opened their eyes, fattened up, and grew coats of white wool, the researchers reported. According to the researchers, the plastic "biobag" womb contains a mixture of warm water and added salts, similar to amniotic fluid, to support and protect the fetus – and the fluid is inhaled and swallowed by the growing fetus just as would happen in the womb, the BBC reported. But since the bagged lamb cannot get a supply of oxygen and nutrients from its mother through the placenta, it's connected to to a special machine by its umbilical cord, which does the job. The whole system is designed to closely mimic nature and buy the tiniest newborns a few weeks to develop their lungs and other organs. "The challenging age that we are trying to offset is that 23- to 24-week baby who is faced with such a challenge of adapting to life outside of the uterus on dry land, breathing air when they are not supposed to be there yet," Partridge told the BBC.