y miscarriages occur away from clinical sites, making the recovery of fetal tissue difficult. Further, fetal cells from miscarriages and ectopic pregnancies often exhibit high rates of abnormalities, precluding their use in research and therapy.
Fetal tissue transplants have numerous potential medical applications. Possible transplantation sites include the brain, the spinal cord, the thymus, the pancreas, and bone marrow. Tissue from the thymus area of the fetus could possibly treat leukemia, aplastic anemia, inherited metabolic disorders, radiation injuries, and severe combined immune deficiency. Possible applications of fetal neural tissue include vision impairment, spinal-cord injuries, memory deficits, and degenerative disorders such as Huntington's chorea, Alzheimer's disease, and Parkinson's disease. Implants from the fetal pancreas have been used with some success in treating diabetes (albeit patients still need insulin) and certain genetic diseases.
The use of fetal tissue transplants in the treatment of Parkinson's disease has been widely publicized. Parkinson's is a degenerative disease that afflicts one-half million Americans. In Parkinson's disease, cells in the region of the brain stem die and are thus no longer able to supply the neurotransmitter dopamine. The disease begins with tremors in the extremities, then proceeds relentlessly to the entire nervous system. The advanced stage of Parkinson's results in uncontrollable movements, rigidity, and even paralysis. Because mental capacity remains undiminished until the onset of the late stages of the disease, victims undergo extreme mental anguish as the symptoms progressively worsen. As one Parkinson's patient remarked, "If everyone involved in the [fetal tissue] debate could have Parkinson's for one month, they'd change their minds" (5:53).
In the treatment of Parkinson's disease, physicians graft fetal tissue cells onto the brain in hopes of stimu...