Video of a lamb fetus in an artificial womb

Fetal lambs survived for weeks in an experimental artificial womb, and scientists hope that the breakthrough could lead to new treatments for premature babies and perhaps the dreamed-of machine utopia where humans are kept mindlessly writhing in translucent plastic sheaths filled with psuedoamniotic liquid.

Physicians at the Children's Hospital of Philadelphia placed fetal lambs into the transparent bags and connected their umbilical cords to a machine that oxygenated their blood. The lambs own hearts provided the pumping power.

Eight lambs survived for as long as four weeks inside the devices. The gestational age of the animals was equivalent to a human fetus of 22 or 23 weeks, about the earliest a human baby can be born and expected to survive outside the womb. A full-term baby is born at 40 weeks.