Where do scientists get the embryos they use?
From in vitro fertilization (IVF) clinics. Many women who have difficulty having a baby use IVF. Doctors collect eggs from the mother and sperm from the father, and put them together in the laboratory. The doctors implant one or more of the resulting embryos in the mother. Other embryos are frozen and stored, in case the first embryo implanted doesn’t take. But all of those frozen embryos may not be used. According to federal policy, embryonic stem cells used for research can only come from embryos created for reproductive purposes that are no longer needed and the donors must consent and not profit financially from the donation.
