Figure from a 2017 Nature Communications paper describing an extra-uterine life support system, or "biobag", used to grow lamb fetuses.[1]
An artificial womb or artificial uterus is a device that allows for extracorporeal pregnancy,[2] by growing a fetus outside the body of an organism that would normally carry the fetus to term.[3] An artificial uterus, as a replacement organ, could have many applications. It could be used to assist male or female couples in the development of a fetus.[2] This can potentially be performed as a switch from a natural uterus to an artificial uterus, thereby moving the threshold of fetal viability to a much earlier stage of pregnancy.[2] In this sense, it can be regarded as a neonatal incubator with very extended functions. It could also be used for the initiation of fetal development.[2] An artificial uterus could also help make fetal surgery procedures at an early stage an option instead of having to postpone them until term of pregnancy.[2]
An artificial uterus or incubator can also serve as a tool for wildlife conservation and de-extinction by eliminating the need for surrogate animals and mass-increasing numbers for critically endangered species such as the sand tiger shark.[4][5] In addition, some recently extinct species can only be conceived through an artificial womb, as they are too distinct from their closest living relatives.[6]
In 2016, scientists published two studies regarding human embryos developing for thirteen days within an ecto-uterine environment.[7][8] In 2017, fetal researchers at the Children's Hospital of Philadelphia published a study showing they had grown premature lamb fetuses for four weeks in an extra-uterine life support system.[1][9][10] A 14-day rule prevents human embryos from being kept in artificial wombs longer than 14 days; this rule has been codified into law in twelve countries.[11] In 2021, The Washington Post reported that "the International Society for Stem Cell Research relaxed a historical '14-day rule' that said researchers could grow natural embryos for only 14 days in the laboratory, allowing researchers to seek approval for longer studies"; but the article nonetheless specified that: "[h]uman embryo models are banned from being implanted into a uterus."[12]