A diagram showing how the artificial womb-like ‘biobag’ nourishes a foetal lamb (The Children's Hospital of Philadelphia)
Philadelphia (US), May 2: We have heard of surrogate mothers. But now scientists have gone a step ahead to develop an artificial womb or the ultimate grow bag. This new invention would help save the children born prematurely.
Extremely premature babies could be kept alive in future using an “artificial womb” that scientists plan to test in humans after a successful study involving unborn lambs.
A plastic bag filled with artificial amniotic fluid – the nutrient-rich liquid that sustains a foetus in the womb – allowed foetal lambs to develop at an age equivalent to 23 weeks in humans.
Premature birth is the main cause of infant mortality, mostly in the rich and developed countries. Human infants born at 23 weeks have just a 15 per cent chance of survival, according to pregnancy research charity Tommy’s. This rises to 55 per cent at 24 weeks, while babies born at 25 weeks have an 80 per cent chance of survival.
These premature babies have a fighting chance of survival. Those who survive are often left with life-long health problems ranging from brain damage to blindness.
To overcome these problems and to ensure full growth of such babies, doctors have developed an artificial womb. In a paper recently published in Nature Communications, a team of doctors working at the Children’s Hospital of Philadelphia, USA, described the artificial womb. They hoped that this ‘ultimate growth bag’ could improve things dramatically, boost the survival rate of the most premature babies and reduce chances of lasting disabilities or deformities.
Premature babies are often placed in incubators to help keep them warm, but the new invention closely replicates conditions in a real womb, scientists at the Centre for Fetal Research at the Children's Hospital of Philadelphia have said.
“This system is potentially far superior to what hospitals can currently do for a 23-week-old baby born at the cusp of viability,” said Dr Alan Flake, the Centre’s director.
“These infants have an urgent need for a bridge between the mother's womb and the outside world. If we can develop an extra-uterine system to support growth and organ maturation for only a few weeks, we can dramatically improve outcomes for extremely premature babies.”
The doctors carried out their experience on a lamb born prematurely to test the efficacy to this artificial womb. They put the lamb in the womb filled with amniotic fluid that keeps the animal’s lungs filled with liquid in a real uterus. Once the fetus is placed inside, the bag is sealed to prevent germs getting inside. The cannulas which carry blood away to be recharged with oxygen and nutrients are inserted into the anima’s umbilical cord, and the tubing in oxygen-exchange system is short, which lets the researchers dispense with pumps entirely. Instead they rely on the animal’s own heart to push blood around the system.
And the results are impressive. The artificial womb kept the lamb alive for four weeks which is longer than any previous attempt. The lamb developed normally, growing wool and moving around as they would in a natural womb. When Dr Alan Flake, who led the team of doctors in this experiment, dissected the lambs, they found no evidence of any strokes or any anomaly that sometimes afflict premature babies in conventional incubators.
The aim of this artificial womb or the ultimate growth bag is to produce a system that could help human babies born prematurely at 23 weeks to grow in normal way and without any disorder or anomaly. In normal course the survival rate of such babies is between a third and half and that too with much heroic efforts.
The researchers believe their new system could be ready for human trials in three to five years, but stress there is no question of using the system to replace a mother's womb at earlier stages of development – which could raise fears of sci-fi technology and the end of conventional pregnancy.
The doctors need to reduce the size of the artificial womb if it were to cater to the premature human babies. Moreover, parallels between lambs and human babies are not perfect. Any procedure applied to such delicate patients will require a lot of proving before it gets the go ahead nod from the authorities.