How do we obtain stem cells from embryos?

Most embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body. read more

Embryonic stem cells come from embryos created for in vitro fertilization. For the procedure, doctors create a number of fertilized embryos, halting their development 4 or 5 days past fertilization at the blastocyst stage. read more

Embryonic stem cells are obtained by killing the embryo. Some bioethicists believe that any human organism, even an embryo, is a human person with the same rights as any other person. To them, removing the inner cell mass and killing the embryo is equivalent to murder. read more