section_path: Abstract
section_name: Abstract
paragraph_text: An artificial womb or artificial uterus is a device that allows for extracorporeal pregnancy, by growing a fetus outside the body of an organism that would normally carry the fetus to term. 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. 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. 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. 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.
  
  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. In addition, some recently extinct species can only be conceived through an artificial womb, as they are too distinct from their closest living relatives.
  
  In 2016, scientists published two studies regarding human embryos developing for thirteen days within an ecto-uterine environment. 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. 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. 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: "uman embryo models are banned from being implanted into a uterus."