While the birth of baby lambs rarely makes headline news, when the lambs are incubated using an artificial womb, it turns heads. As reported in a recent study, extremely premature lambs successfully grew inside an artificial womb for three to four weeks. The feat means we're closer to using such a device on human premature infants.

The researchers tested five lambs whose biological age was equivalent to 23-week human preemies, and three more a bit older in an artificial womb, called a “Biobag.” The womb is a fluid-filled transparent container meant to simulate how fetuses float in the amniotic sac inside the mother’s uterus, Yahoo reported. The sac is attached via the umbilical cords to a mechanical placenta that keeps the blood oxygenated while removing carbon dioxide. Results showed that all the lambs developed correctly without any notable health problems.

Read: Premature Birth: Babies Born At 28 Weeks Struggle With School And Adult Life

"We start with a tiny fetus that is pretty inert and spends most of its time sleeping. Over four weeks we see that fetus open its eyes, grow wool, breathe, swim," said study lead author Dr. Emily Partridge, Yahoo reported. "It's hard to describe actually how uniquely awe-inspiring it is to see."

Most of the lambs were euthanized before they reached full gestations for further study, but one was left to bottle wean and is now a healthy grown sheep. Human testing is still several years away, but the recent incubation of the lambs is a good sign of the device’s possible success on human infants.

The device could be important for not only ensuring the survival of extremely premature babies, but also helping boost their long-term health. This is because more time in the womb is associated with a number of health benefits, including enriched brain development. That’s not saying that a premature baby will not be as intelligent as a baby born later, but a 2016 study found that full-term babies experience more brain growth during the third trimester (final 13 to 14 weeks of pregnancy) compared to premature infants, who are born before 37 weeks.

Source: Partridge EA, Davey MG, Hornick MA, et al. An extra-uterine system to physiologically support the extreme premature lamb. Nature Communications . 2017

See Also:

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Premature Birth Rate Increases In US For First Time In 8 Years