VALENCIA, Spain—The first human clinical trials testing an artificial placenta called EXTEND could be underway by this time next year, according to Alan Flake, MD, from the Children’s Hospital of Philadelphia in Pennsylvania.

The 20th World Congress in Fetal Medicine being held in Valencia, Spain. (Photo by Larry Luxner)

Dr. Flake gave an overview of the timeline for the clinical implementation of the artificial placenta during his lecture at the 20th World Congress in Fetal Medicine being held here June 25-29, 2023. 

The Investigational Device Exemption application to the US Food and Drug Administration (FDA) for the artificial placenta is envisaged for September or October 2023, Dr. Flake said.

He said EXTEND was shown to physiologically support a fetal lamb for 25 to 28 days. The lamb had normal fetal circulation, cardiovascular parameters, heart function, oxygen delivery, somatic growth, metabolism, and lung, brain, and gut development. 

“The system is robust and stable,” Dr. Flake said, adding that it has been applied to over 300 lambs already. He also said researchers have not observed any acute irreversible events that can be life-threatening or cause neurological injury, such as irreversible cord spasm, circuit thrombosis, cannula erosion or dislodgement, major hemorrhages, or organ failure.

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“Ultimately, it is for the FDA to decide,” Dr. Flake said outlining the agency’s concerns about the limitations of the lamb model such as cardiac output and placental blood flow being significantly higher in the lamb, the size of the lamb, and the structure of the umbilical cord being completely different in sheep compared to humans.

All these limitations were addressed using a porcine model, which is much more similar to humans, and it has been shown that EXTEND can maintain normal fetal physiology, support normal organ development, and is safe in lamb and porcine models, he said.

The next question that remains to be answered is whether its application to extremely premature infants is feasible.

EXTEND, or EXTra-uterine Environment for Neonatal Development, is an artificial womb to maintain extremely premature fetuses in a fluid environment while supporting them with nutrition and gas exchange via umbilical catheters and an external membrane oxygenator.


Flake A. Artificial placenta: time line to clinical implementation. Oral presentation at: 20th World Congress in Fetal Medicine; June 25, 2023; Valencia, Spain.