Heart Valves from Stem Cells:

Last week, at the American Heart Association conference, scientists reported on the results of experiments in which heart valves were grown from stem cells extracted from amniotic fluid. The fluid was obtained during amniocentesis, a prenatal test for birth defects. The theory behind this experiment was that, if prenatal tests indicated that the infant had congenital heart defects, then the new heart valves could be grown while the infant was still developing and be used as replacement valves when the infant was born.

If this procedure becomes more developed, there are both practical and ethical advantages. As the Associated Press article notes, from a practical standpoint, replacement valves from human cadavers or animals may deteriorate and may not grow as the infant matures—implying the need for additional medical and/or surgical interventions. By contrast, using living cells from the infant opens up the possibility that the valves might grow with the infant.

A major advantage of this procedure, however, is ethical—it involves using cells that the fetus sheds in amniotic fluid, which means that no embryo has to be destroyed to get the stem cells. Given that the destruction of embryos to obtain stem cells has been at the center of political and religious debate about stem cell research, this development may offer a middle ground on which both sides of the dispute could agree.