An artificial womb has been invented that researchers say can support the growth of premature lambs for a month, as if they had still been growing inside their mother.
The hope is that one day this technology will be used to aid the development of severely premature babies.
At least two lambs were able to grow for up to 28 days inside the artificial womb, far outstripping previous attempts using similar models which could only support animals for 60 hours and lead to brain damage.
The lambs in the artificial womb longer showed normal breathing, swallowing, opened their eyes, grew wool, and had normal growth and neurological function, report researchers from the Centre for Fetal Research at the Children’s Hospital of Philadelphia.
While the invention sounds more science fiction than reality, it could be taken to human trials with the hope of improving respiratory and neurological outcomes for extremely premature babies as soon as within three years, they say.
The lambs were submerged inside a plastic sac that is filled with laboratory created amniotic fluid. Their heart pumps blood through their umbilical cord via an external oxygenator, which does the work of a mother’s placenta.
This way the animal gets oxygen as it would in the womb, through blood, rather than by using its underdeveloped lungs, buying time for the lungs and other organs to grow normally.
The researchers – lead by the Centre’s Alan Flake, Emily Partridge and Marcus Davey, an Australian fetal physiologist, went through four prototypes over five years honing their technique, which was published today in Nature Communications.
The final method was tested on eight lambs. Complications along the way included issues with sepsis, lambs not surviving delivery and poor oxygenation.
Some lambs who survived outside of the artificial womb still appear healthy up to a year and a half later, including one animal that’s retired to a farm in Pennsylvania, Dr Davey told Fairfax Media.
“We’ve had several animals since the paper was first submitted that have come out of the system and for all intents and purposes looking at those animals everything appears normal from a neurodevelopmental standpoint,” he said.
The researchers want the womb to one day be used in neonatal intensive care units as an alternative to ventilation for babies born at 23 weeks gestation onwards.
They do not intend to challenge the currently accepted age standard for a viable infant.
“These infants are born very early and their lungs are really underdeveloped, they’re not ready to be breathing post-natal air gases and what we do with these infants we put them on a ventilator and we give them oxygen which are really damaging to the lung,” Dr Davey said.
“Rather than transitioning to post-natal life in terms of breathing respiratory gases, we feel the best way to treat these infants, or we treat them as fetuses, is to return them to a womb-like environment.”
The artificial womb study has been fast tracked by the US Food and Drug Administration and the researchers are currently undertaking further animal trials, which they hope to complete within two years, “then move on to first in human use within three to four years,” Dr Davey said.
“It is moving very quickly.”
Associate professor David Tingay, a neonatal researcher at Murdoch Childrens Research Institute, said people had been trying to create an artificial womb for more than 50 years and this model was the most promising yet. But he cautioned it could be a long time before this sort of technology was being used in hospitals.
“[The womb] appears to do what others haven’t been able to do, which is to keep the animal alive for a long period of time and show that it’s growing normally,” he said.
“This is a very promising research finding, which will help us better understand how to support pre-term babies but there’s still need for caution and we would be a long way – I would estimate a decade or more – before we would be able use this knowledge in the NICU.”