Lamb fetus in Biobag. Source: South China Morning Post
Researchers have created a way to support prematurely born babies during the crucial final stages of development. Prematurity is the leading cause of death in newborns. Approximately 10% of babies in the US are premature and while many survive and become healthy, their chances of survival are greatly reduced. Many premature babies require constant medication and nutrition and will often still experience health issues due to incomplete organ development.
Alan Flake, a fetal surgeon at the Children’s Hospital of Philadelphia and head author of the paper, and his team have developed what they call a “Biobag” that simulates the conditions of the womb and allows newborns to continue developing until they come full term.
The Biobags work by providing a sterile, dark, and temperature controlled environment for the lambs to continue developing. The clear plastic encloses the fetal lamb and provides a safe environment like a womb would. The lamb is bathed in an electrolyte rich solution that acts as a replacement for the amniotic fluids found in the womb. The lambs are also linked to an oxygen exchanger as well as a constant supply of medications and fluids so that they can breathe and absorb the necessary nutrients required to develop properly.
The team has successfully raised 6 lambs born at the equivalent 23 weeks in human pregnancy in the Biobag. Immediately after removal via caesarean section, the lambs were placed in the Biobags and hooked up to the gas exchangers that would allow them to breathe and continue developing.
Over the course of about 4 weeks, the lambs’ organs continued growing and they began moving around and learning to swallow just as they would have in the womb. After the 4 weeks, the lambs were moved to regular ventilators designed for premature babies in a NICU. Their lung function and oxygen intake was nearly identical to lambs that had been born via caesarean section after developing in a natural womb.
Source: The Children's Hospital of Phildelphia
After developing, a few lambs were euthanized so researchers could examine their organs. Their lungs and brains – the organs most susceptible to damage in a premature fetus – appeared undamaged and normally developed.
Emily Partridge, a doctor for critically premature infants at Children’s Hospital of Philadelphia and co-author of the paper, describes the technology and development of the lambs as “an awe-inspiring sight”.
While incredible, the authors of the paper acknowledge that the public may be weary of their success.
“I don’t want this to be visualized as humans hanging on the walls in bags,” said Flake. “This is not how this device will work or look.”
In the future, Flake expects the Biobags to be still be carefully monitored by people and cameras and not strewn about like a scene from a sci-fi movie.
Many more years of research will need to be done before a viable and safe artificial womb is approved for human use. A successful artificial womb could conceivably save hundreds of lives, especially babies born before 24 weeks that only have around a 15% chance of survival. The wombs would provide a safe place for the babies to fully develop that would drastically raise their chances for survival.
Every day a baby spends in the room greatly increases its chances for survival. At 23 weeks the chance of survival is 15%, at 24 weeks it’s 55%, and at 25 weeks it jumps to 80%. The Biobag would provide the crucial few weeks of development needed for a baby to have the best chance of survival.
Flake says “it’s realistic to think about three years for first-in-human trials” and has already begun testing on human sized lambs that were placed in the Biobags even earlier on in pregnancy. They have carefully monitored the lambs’ development in the womb and long term growth after birth to ensure the Biobags are producing healthy newborns.
While this is very good news for the health and prospects of infants, many academics are not as optimistic as Flake and his team.
Colin Duncan, a professor of reproductive medicine and science at the University of Edinburgh, agrees that the technology is a major advance, but sees a much longer amount of research and testing time before it is applied to humans. “The use of steroid injections for women at risk of delivering a premature baby to help accelerate fetal lung development was discovered using sheep models. It has improved the survival of premature babies worldwide and made a huge impact on obstetric and neonatal practice. That treatment took well over 20 years to get into clinical practice.”
Source: Becker R. An artificial womb successfully grew baby sheep – and humans could be next. The Verge. April 25, 2017.