Scientists reported Sunday they had found a plentiful source of stem cells in the fluid that cushions babies in the womb and produced a variety of tissue types from these cells - sidestepping the controversy over destroying embryos for research.

Researchers at Wake Forest University and Harvard University reported the stem cells they drew from amniotic fluid donated by pregnant women hold much the same promise as embryonic stem cells. They reported they were able to extract the stem cells without harm to mother or fetus and turn their discovery into several different tissue cell types, including brain, liver and bone.