[Reproduction without a uterus? State of the art of ectogenesis]

The concept of reproduction without uterus, or ectogenesis, has long been considered a myth. Nowadays, however, the in vitro conception (IVF) and embryo culture before implantation are largely used in humans with more than 50,000 IVF and ICSI procedures yearly in France, but also in ruminants where about 400,000 bovine embryos are produced in vitro worldwide each year. In order to proceed with gestation, a 3D structure enabling implantation is needed. Ex-vivo implantation of human embryos was obtained both in a perfused ex-vivo uterus and in a 3 dimensional culture of endometrial cells, but these experiments were stopped because of ethical concerns. The implantation of a mouse embryo in a similar 3D structure has been reported but did not lead to the production of a live pup. Another interest for an artificial uterus or placenta would be to use it for ex-vivo maturation of very premature fetuses. Extra-corporal membrane oxygenation (ECMO) was developed for many years but its use remains disappointing in preterm infants when compared to the important progress made with more classical clinical care. In any case, goat fetuses have been maintained alive up to 9 days in an artificial amniotic pouch, being oxygenated via ECMO.