Do stem cells come from aborted fetuses?
One potential source of stem cells comes from early fetal tissue recovered during a narrow window of development. In development, an embryo is called a fetus at about 7-8 weeks following fertilization. At about 4-5 weeks of development, embryonic germ cells, the precursors to the egg and sperm cells, are found in the developing ovary or testis, structures only about 2 mm long.
