The groundwork is being laid for the first human trial of an artificial uterus, which could get the go-ahead from the US Food and Drug Administration (FDA) some time in 2024.
Artificial uteruses are designed to mimic the environment of the womb as closely as possible and may help support babies who are born extremely prematurely, at around 23 or 24 weeks鈥� gestation.
鈥淭he idea is to bridge the rough patch when they鈥檙e really struggling and carry them through to a point when they can do OK,鈥� said at Children鈥檚 Hospital of Philadelphia, Pennsylvania, , her team鈥檚 artificial uterus system, which has shown promise in animal studies.
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Extremely preterm babies have difficulty breathing, even with the help of mechanical ventilators. This is because their immature lungs struggle to transition from being filled with fluid, as they were in the uterus, to breathing air. Being unable to breathe properly is one of the main reasons why , and why those who do often develop brain damage or other medical conditions.
The EXTEND system consists of a 鈥渂io-bag鈥� filled with warm, lab-made amniotic fluid to mimic the uterus鈥檚 environment. The idea is that a preterm baby could be placed inside the bag straight after delivery to retain fluid in their lungs. Surgeons would also connect blood vessels in their umbilical cord to tubes for delivering oxygen, nutrition and medicines.
Experiments involving more than 300 preterm lambs showed that the artificial uterus kept them alive and facilitated healthy development of their lungs, brains and other organs.
Off the back of these, the FDA has signalled that it may soon approve a first-in-human trial of the system. In September, more than two dozen neonatologists, paediatricians, bioethicists and other experts to discuss what such a trial might look like.
鈥� one of EXTEND鈥檚 developers, also at Children鈥檚 Hospital of Philadelphia 鈥� told the meeting that he believes the team鈥檚 preclinical data 鈥渋s adequate for consideration of a carefully designed clinical study鈥�.
The panellists weighed up potential risks and benefits, and discussed ethical dilemmas regarding how to recruit the first trial subjects. For example, , a neonatologist and bioethicist at Yale University, noted that preterm labour is 鈥渙ften a setting of fear, of exhaustion, of urgency and pain鈥�, meaning parents may not be in the right frame of mind to provide proper consent.
However, Mercurio also said that he believed the artificial uterus鈥檚 potential benefits could outweigh any of its risks if it were first offered to help extremely preterm babies with less than a 20 per cent chance of survival. 鈥淚 think this is a very promising technology, and while I think we have to approach it with caution and eyes wide open, and with an open and thorough discussion of the ethical issues, I think we should move forward with those discussions,鈥� he told the meeting.
The technology鈥檚 development has led some to wonder whether the next step will be using artificial uteruses to grow babies all the way from in vitro fertilisation embryos, bypassing the need for pregnancy altogether.
However, writing in The Journal of the American Medical Association in June, 鈥渘othing more than a technically and developmentally na茂ve, yet sensationally speculative, pipe dream鈥�. Early organ development relies on chemical signals that an artificial uterus cannot supply and the blood vessels of fetuses younger than around 23 weeks鈥� gestation would also be too tiny to connect to it, they argue.
The FDA barred the public from the section of the meeting in which it and the EXTEND developers discussed the potential timing of a clinical trial. We will therefore have to watch this space to see if one does get the green light in 2024.
