Artificial Placenta Keeps Premature Lambs Alive for 28 Days

(Credit: Soonthorn Wongsaita/Shutterstock) Lamb fetuses have been sustained for four weeks outside of their mothers' bodies with a new system that mimics a placenta. The system is a step forward for researchers hoping to develop an "artificial placenta" that could allow premature fetuses to continue developing until they are ready for the outside world. It is essentially a fluid-filled bag with ports that allow for oxygen and nutrient delivery, combined with a pump-less oxygenator that allows the fetus to circulate blood using its own heartbeat.