Posted on May 8, 2017 at 7:41 PM
by Craig Klugman, Ph.D.
An announcement last week took the science dream of an artificial womb one step closer to science fact: premature lambs were gestated in a biobag (technically an “extra-uterine system”). The researchers were trying to solve a problem surrounding premature human births—babies born critically early (before 26 weeks) have severe complications that lead only half to survive. The survivors often suffer from life-long medical conditions and developmental challenges. Those babies need more time in the womb to develop.
In the experiment, 8 lamb fetuses between 105 to 115 days gestational age (lambs usually reach term at 145 days) were removed from their mother’s uterus and placed in an artificial womb. They developed normally. The system used a bag, an amniotic fluid substitute, and gas exchange units to provide oxygen and remove CO2 from the lamb fetuses. The lamb’s own heart provides the pump for the system. The bags were placed on heating plates to maintain a constant temperature of 39.5oC. All of the lambs were “decanted” (to borrow a term from Huxley) and seemed normal. Seven of the lambs were euthanized for anatomical and physiological study. The 8th lamb has developed and grown normally.
The researchers hope that they can perfect their system with further testing on animals in the next two years. They envision human trials in three to five years. The system still requires an embryo and fetus to be gestated in a natural womb, but in the event of a premature birth, the Biobag could provide a better outcome than current treatments. For use in humans, the bags would likely be kept in dark rooms to mimic light and heartbeat sounds would be played so that the fetus would experience in an in-vivo environment.
The science fiction nerd in me is excited at this possibility. How cool is this? You don’t need high technology, robots, or huge machines to gestate a fetus. You need a plastic bag, tubing, amniotic fluid, and gas exchanger. There are no mechanical parts.
The ethicist in me asks us to take a step back and to examine the issues in this case. Consider that if it is possible to vastly improve survivability of a 23-week-old fetus, then we may need to re-consider the notion of abortion at that age. Perhaps instead of an abortion, a fetus would be transplanted into a biobag and then adopted. Scott Gelfand of Oklahoma State worries that this possibility could be required by the state. At a time when many states are trying to pull back the limits of abortion to 20 weeks, this experiment might give them support. Dena Davis in an NPR article is concerned that previous notions of the duality of viability—that baby either is born or is not born—could be muddled into being “halfway born, or something like that.” For legal purposes, would the birthday be transfer from uterus-to-bag date or the decanted date?
Brave New Wool
Consider a scenario in which women are required to be tested for substance abuse and if positive, then the state might require the fetus to be transferred, even against the woman’s wishes. Then in the bag, the fetus could be weaned from any addiction. Or if a person is convicted of a crime, would a state require such a transfer so that a child is not born in prison? Could notions of child abuse and removing children from a home be pushed back to 23 weeks gestation? What about elective transfers? Consider if someone did not want to experience the physical effects of the last trimester of pregnancy and thus electively wanted to gestate her fetus after 25 weeks in the biobag? Drawing lines for regulations and standards of practice are always a challenge and require significant critical thinking and asking of questions.
Davis also expressed concern about whether a baby in the bag would experience more pain and suffering then under standard treatment or even death. Whether animal models would allow for testing for the experience of pain is unknown at this time. What techniques to measure pain would need to be developed?
What of the animals in the experiment? Researchers report that they followed all IACUC guidelines and chose a lamb model because much embryological research has been done using that animal model. Some have expressed outrage at euthanizing the lambs, but it was necessary to gain information on internal development such as lung capacity and brain growth, as well as organ sizes and weights.
What of the first experiments in humans with this technique? When human trials are reached, more animal studies will have been done, likely even with a primate model. There will come a point, however, where a woman in premature labor will be asked to consent for her about-be-born premature baby to be removed via C-section and placed into a Biobag instead of receiving the traditional treatment. Given the mixed success rate with traditional methods, achieving equipoise should not be difficult. Still, it will take bravery to be the among the first women to agree to this experiment. On the other side, there will be the ability to study and observe late fetal development in a new way. Parents can presumably visit with their developing transplanted fetus and post pictures on social media. It’s not far fetched when you consider that one reason this experiment has gotten so much traction is the videos of cute bagged lambs.
These caveats and concerns are not substantially different than the arguments that were made about human cloning and even test tube babies. The dystopian perspective is important to help us develop regulations and protocols for making good decisions that protect people. But, it seems to me that the benefits of being able to save these babies naturally born prematurely far outweigh our concerns about potential changes in meaning of birth and rebalancing maternal-fetal rights, at the moment. Besides, at this time the procedure is experimental and we do not know if it will work on humans that gives us time to consider the possibilities.
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