The UK government has given permission for scientists to genetically modify human embryos for the first time.
Scientists will study embryos during the seven days following fertilization, and specifically look into what causes miscarriages.
The experiments will be conducted at London's Francis Crick Institute, and are intended to answer questions about the first moments of human life.
The scientists are forbidden from implanting the embryos in a living person, so there is no possibility that they will end in live births.