Engineers at Children's Hospital of Philadelphia built a fluid-filled bag meant to extend development for animals born at an equivalent stage, replacing a ventilator and incubator with something closer to the uterus itself.
Eight lamb fetuses, at a developmental stage matching roughly 23 weeks of human pregnancy, were transferred into the sealed, fluid-filled Biobag through a catheter in the umbilical cord, with no ventilator or external pump. The longest runs lasted 28 days, and the lambs kept growing, opening their eyes and growing wool.
The lambs were removed from the device once each run ended rather than being raised to term, so long-term outcomes in this model are still untested, and no human infant has ever been placed in such a system. The technology aims eventually at extremely premature human babies, but any human use would need years of additional safety work first.
Read the original study
Partridge et al., Nature Communications, 2017 · doi.org/10.1038/ncomms15112
Lambs breathed fluid, not air, for weeks.
Source
- Partridge, E. A., Davey, M. G., Hornick, M. A., McGovern, P. E., Mejaddam, A. Y., Vrecenak, J. D., Mesas-Burgos, C., Olive, A., Caskey, R. C., Weiland, T. R., Han, J., Schupper, A. J., Connelly, J. T., Dysart, K. C., Rychik, J., Hedrick, H. L., Peranteau, W. H., & Flake, A. W. (2017). An extra-uterine system to physiologically support the extreme premature lamb. Nature Communications, 8(1), 15112. https://doi.org/10.1038/ncomms15112