Scientists create first synthetic human embryo, raising ethical concerns.

Scientists have created the first synthetic human embryos using stem cells, which could help researchers study the earliest stages of human development and explain pregnancy loss. However, the rapid progress has outpaced discussions on how they should be dealt with ethically and legally. The synthetic embryos are not legally "embryos" and are not governed by the same laws as traditional embryos. Legal and ethical experts in the UK are drawing up a voluntary set of guidelines for how to proceed.