In science, ethical guidelines ensure that research takes place in a way that respects public trust and is conducted responsibly. Traditional ethics approval procedures work well for projects following established practices, but they offer little flexibility when unexpected challenges, novel approaches, unanticipated research directions, or unforeseen results arise. For research exploring uncharted ethical ground, such as studies with human stem-cell-based embryo models (hSCBEMs), conventional ethical approval approaches are therefore no longer suitable.