Despite being a developed and leading country, the United States suffers from infant morbidity and mortality due to premature births, which causes ⅓ of all infant deaths and ½ of cerebral palsy in infants [1]. Advances in neonatal care have improved survival rates for premature infants, but those that do survive are plagued with a myriad of complications from underdeveloped organs such as lung disease from underdeveloped lungs [1]. The best solution would be to keep them in the womb until they are fully developed, which is not possible. The next best solution would be to keep them in an artificial womb that simulates the real thing, which is still not possible yet (but hopefully soon will be).
Partridge, E. A. et al recently published an article in Nature Communications detailing their work into developing an artificial womb for premature lambs that simulates premature humans at 23 weeks. The artificial womb is essentially a plastic bag that contains amniotic fluids (simple water and salt solution in this case), which is continually pumped in and out to keep it fresh, and a tube connecting to the umbilical cord, which feeds the lamb fetus all essential nutrients and assists in any gas/fluid exchange that would normally occur between the mother and fetus. The researchers found that the artificial womb could support the premature fetus for up to 4 weeks. During that time, normal organ development was observed as well as normal blood flow, gas flow, and brain activity. The success of this experiment represents a step forward towards building a stable artificial womb for humans but more testing is required before anything akin to this can be used on humans.
The artificial womb created here by Dr. Emily Partridge and her team is not without concern. First and foremost is the risk of infection [2]. Although this is a closed system, any contaminants that get into the amniotic fluid before it is brought to the fetus would then be directly introduced to the fetus. Similarly, the exchange system at the umbilical cord can be potentially contaminated. With the premature fetus having a weak immune system even the weakest contaminant would be bad. The other big issue is adapting it for use on humans. The amniotic fluids for the premature lamb was a simple water and salt solution [2]. For humans, it would need to be considerably more complicated to ensure optimized and minimal problems during development. More study on this particular matter is needed and is the focus of Dr. Partridge and her team [1]. There have been many other attempts at creating an artificial womb but this represents one of the more successful attempts. Human trials are still a few years away as the team works to minimize any risks that may occur. With survival rates for premature infants born less than 23 weeks, at 23 weeks, at 24 weeks, and at 25 weeks being 0%, 15%, 55%, and 80% respectively, it becomes extremely important to find a solution that would buy them enough time to survive, which an artificial womb might do.
Dr. Partridge and her team developed the artificial womb solely for premature births, but research into artificial wombs can go beyond that whether anyone wants them to or not. Previously, I wrote about Dr. George Church bringing back the woolly mammoth. One of the hurdles that he and his team face is building an artificial womb that could house the mammoth fetus and allow it to grow from embryo to fully grown baby. Although the artificial womb discussed here can only go up to 4 weeks, it was still fairly successful and this means that researchers can use it as a template to build better ones for longer periods of time. Once the artificial womb becomes usable in humans, it can potentially change how we discuss and go about reproduction. For people who cannot bear children for various reasons, they rely on surrogates or expensive IVF treatments for example. An artificial womb would give them another option. There may even come a point where people simply rely on an artificial womb to carry a child term. These scenarios are long ways off as we still try to figure out how to actually make a stable artificial womb, but they are worth taking time to think about.
Photo acquired from BBC News