An illustration of a fluid-filled incubation system that mimics a mother’s womb, in hopes of one day improving survival of extremely premature babies.
AN ARTIFICIAL womb has been successfully used to incubate baby lambs and researchers hope the technology will soon be able to do the same for premature human infants.
The watery incubation system is the first of its kind so closely mimics the conditions of the womb that it could give premature babies a much better chance at starting life.
Today, premature babies weighing as little as a 450 grams are hooked to ventilators and other machines inside little special capsules.
For those that survive, they will often struggle with simple bodily functions that we take for granted such as walking, talking, seeing, hearing.
Lamb grows in external womb
But the creation of an artificial womb could allow them the chance to better continue their development of their lungs and other important organs before being brought into the world.
The contraption which amounts to a prenatal fluid-filled plastic bag with an attached mechanical placenta could give them the precious extra few weeks they need.
Premature babies face a number of daunting challenges.Source:Supplied
“Our system could prevent the severe morbidity suffered by extremely premature infants by potentially offering a medical technology that does not currently exist,” said the study’s lead author Dr Alan Flake.
He is a foetal surgeon and the director of the Center for Fetal Research in the Center for Fetal Diagnosis and Treatment at Children’s Hospital of Philadelphia and has high hopes for the project.
“We’re trying to extend normal gestation,” he said.
Increasingly hospitals attempt to save the most critically premature infants, those born before 26 weeks gestation and even those right at the limits of viability — 22 to 23 weeks.
Extreme prematurity is a leading cause of infant mortality, and those who do survive frequently have serious disabilities such as cerebral palsy.
About one in 10 Australian babies are born prematurely, considered to be those born before 37 weeks gestation.
The researchers created a fluid-filled transparent container to simulate how foetuses float in amniotic fluid inside mum’s uterus, and attached it to a mechanical placenta that keeps blood oxygenated.
In early-stage animal testing, extremely premature lambs grew, apparently normally, inside the system for three to four weeks, the team reported.
The lambs grew wool and even opened their eyes inside the artificial wombs. Picture: Nature CommunicationsSource:Supplied
In the current study, the researchers describe the evolution of their system over three years, through a series of four prototypes, beginning with a glass incubator tank, and progressing to the current device.
The eight preterm lambs tested in the most recent prototype were physiologically equivalent to a 23 or 24-week-gestation human infant.
The idea of treating premmies in fluid-filled incubators may sound strange, but physiologically it makes sense, Dr Catherine Spong, a foetal medicine specialist at the National Institutes of Health told the Associated Press.
“This is really an innovative, promising first step,” she said.
One of the biggest risks for very young premmies is that their lungs aren’t ready to breathe air, she explained. Before birth, amniotic fluid flows into their lungs, bringing growth factors crucial for proper lung development.
Foetal physiologist Marcus G. Davey of the Children’s Hospital of Philadelphia, who helped design the artificial womb system. He is shown near giant tanks holding a liquid designed to simulate amniotic fluid.Source:AP
HOW THE “BIOBAG” WORKS
The premature lambs were delivered by C-section and immediately placed into a temperature-controlled bag filled with a substitute for amniotic fluid that they swallow and take into their lungs.
“We make gallons of this stuff a day,” said foetal physiologist Marcus Davey. It’s currently an electrolyte solution but he’s working to add other factors to make it more like real amniotic fluid.
Then the researchers attached the umbilical cord to a machine that exchanges carbon dioxide in blood with oxygen, like a placenta normally does. Then the lamb’s heart circulates the blood, without the need for any other pump.
The scientists tested five lambs and all of them appeared to grow normally, with blood pressure and other key health measures stable and few complications during the weeks they were inside the device.
The study didn’t address long-term development. Most of the lambs were euthanized for a further study that found normal organ development for their gestational age. One was bottle-weaned and is now more than a year old, apparently healthy and living on a farm in Pennsylvania.