Resolution criteria

This market resolves YES in the year that an animal is born alive after having been gestated entirely ex vivo (outside a biological body) from conception through to birth. The animal must be delivered alive and viable.

"Entirely ex vivo" means the entire gestation period occurs in an artificial environment - not partial ectogenesis where a fetus is transferred from a biological womb to an artificial system partway through development.

Resolution will be determined by peer-reviewed publication in a major scientific journal or credible news reporting from established science outlets confirming the achievement. The animal species is not restricted.

Background

Complete ectogenesis means gestation happens from conception to birth completely outside a human body. Current artificial womb technology has only achieved partial ectogenesis. 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. However, these lambs were transferred to the artificial system after being removed from the biological womb via cesarean section—not gestated entirely ex vivo from conception.

In January 2025, Colossal and University of Melbourne claimed to have developed a prototype artificial marsupial womb that has reached mid-gestation of single-celled marsupial embryos in order to further the de-extinction of the thylacine. Early embryo development in artificial environments has also been demonstrated: researchers have grown mice in an artificial womb for as long as 11 or 12 days, about half the animal's natural gestation period.

The major technical barriers to complete ectogenesis include replicating early embryonic development (currently poorly understood), maintaining hormonal stability, and managing the transition from fetal to neonatal physiology at birth.

Considerations

Most current research focuses on partial ectogenesis for medical applications treating extremely premature human infants, not on achieving complete ex vivo gestation from conception. Complete ectogenesis would require solving fundamentally different problems than extending gestation of already-formed fetuses. Additionally, while significant progress is being made on replicating the conditions of the womb during the latter stages of pregnancy, we still barely even know what's going on during the earliest weeks, partly because research on human embryo development outside the womb was long prohibited beyond 14 days.