The device kept fetal lambs alive for about a month, allowing them to continue to mature. It has not been tested in humans, and some say the device raises ethical questions.
Scientists have created an "artificial womb" in the hopes of someday using the device to save babies born extremely prematurely.
So far the device has only been tested on fetal lambs. A study published Tuesday involving eight animals found the device appears effective at enabling very premature fetuses to develop normally for about a month.
