Ectogenesis (from the Greek ἐκτός, "outside," and genesis) is the growth of an organism in an artificial environment outside the body in which it would normally be found, such as the growth of an embryo or fetus outside the mother's body, or the growth of bacteria outside the body of a host. The term was coined by British scientist J.B.S. Haldane in 1924. Human embryos and fetuses Ectogenesis of human embryos and fetuses would require an artificial uterus. An artificial uterus would have to be supplied with nutrients and oxygen from some source to nurture the fetus, as well as dispose of waste material. There would likely be a need for an interface between such a supplier, filling this function of the placenta. An artificial uterus, as a replacement organ, could be used to assist women with damaged, diseased or removed uteri to allow the fetus to be conceived to term. It also has the potential to move the threshold of fetal viability to a much earlier stage of pregnancy. This would have implications for the ongoing controversy regarding human reproductive rights. Ectogenesis could also be a means by which homosexual and single men could have genetic offspring without the use of surrogate pregnancy or a sperm donor, and allow women to have children without going through the pregnancy cycle. Synthetic embryo In 2022, Scientists of the Weizmann Institute of Science created early "embryo-like structures'" from mice stem cells. The world's first synthetic embryo does not require sperm, eggs nor fertilization and were grown from only embryonic stem cells (ESCs) or also from stem cells other than ESCs. The structure had an intestinal tract, early brain and a beating heart and a placenta with a yolk sac around the embryo. The researchers said it could lead to better understanding of organ and tissue development, new sources of cells and tissues for human transplantation. However, human synthetic embryos are a long ways off. Their research was published by Cell on August 1, 2022. Also in August 2022, a study described how University of Cambridge and the same Weizmann Institute of Science scientists created a synthetic embryo with a brain and a beating heart by using stem cells (also some stem cells other than ESCs). No human eggs nor sperm were used. They showed natural-like development and some survived until day 8.5 where early organogenesis, including formation of foundations of a brain,