With advances in in vitro models, group proposes refined legal definition of an embryo

Thanks to continuous advances in human stem cell research, studies that make use of embryo models are progressing quickly. This research offers both a scientific and ethical alternative to the use of embryos resulting from fertilized human eggs, and the appropriate ethical guidelines have been developed in parallel with the advances being made. A group of biologists and ethicists suggest additions to the current ethical framework that refine thinking about human embryology using embryo models to maximize benefits to society.