Stem cells are one of the keys to life,they potentially nourish,heal and protect us. Stem cells are truly remarkable. They bridge the gap between our origin and what we become. They supply the cells that construct our adult bodies and, as we age, replenish damaged and diseased tissues. A true stem cell is a primitive cell capable of unlimited cell cycles with the capacity to cease being a stem cell and become one of a wide variety of specialized cells that can no longer divide Fetal stem cells cross into maternal blood during pregnancy and thus represent a potential non- invasive source of foetal genetic material for prenatal diagnosis.