Weizmann Institute of science

An artificial model of a human embryo in a developmental stage corresponding to day 12. The upper elliptical structure is the part that will become an embryo including the amniotic sac above it; The lower structure is the yolk sac. The interface between the two structures is an essential element for embryonic development in humans. Both parts are surrounded by a layer of cells which will become the placenta

A human embryo without the need for a sperm egg or uterus

A pregnancy test detected the fetus in the test tube. The artificial models developed from stem cells - without egg, sperm or uterus - and grew in the laboratory until day 14