A team from Israel’s Weizmann Institute has grown something (or somebody?) closely resembling a 14 day-old human embryo without using either sperm or eggs, not to mention a womb. The team calls it “an embryo model” but it’s more than that: made using human stem cells, it even released hormones resulting in a positive pregnancy test in the lab. The institute’s rationale for building such an “model” is “to provide an ethical way of understanding the earliest moments of our lives,” including miscarriage and birth defects. But given there’s nothing synthetic and much that’s human about this model, questions will linger about the ethics of its use. Legally (even in the UK) embryo models are distinct from embryos. It is impossible to implant an embryo model into the lining of the womb leading to an actual pregnancy – at least, for now.
Photograph courtesy of Weizmann Institute of Science