Could We Be Marsupials? Very Premature Babies and Artificial Wombs

It is often pointed out that one cannot be “a little bit pregnant,” but pregnancy’s borders are no longer so crisp. At Children’s Hospital of Philadelphia, scientists have created an artificial womb in which “extremely premature” lambs were nurtured for four weeks, enough to make them ready to meet the world. The goal is to advance this technology until it is available for very premature human infants. At present, we put preemies into neonatal...