tim's journal

Organismically dead embryos

Donald Landry and Howard Zucker at Columbia University [1], in this month's Journal of Clinical Investigation, proposed a new argument for the use of human embryos - when they are "organismically dead". Borrowing from the idea of the determination of brain death, Landry and Zucker argue that the certain human embryos resulting from invitro fertilization (IVF) might be classified technically dead, thus being eligible to donate their organs, i.e., stem cells. About 60% of IVF embryos are "nonviable", meaning that they are unable to develop into babies when transplanted. One signal of nonviability is when cell division, for whatever reason, ceases at the 4- or 8- cell level. At this point the cells may still be alive thus usuable for stem stell research.

Precisely when the life of a human begins remains for some a complicated question, but a general consensus has been achieved on when life ends: life ends when the criteria for brain death are met. However, the criteria for determining the death of the developing human before the onset of neural development have not been formulated. We believe that when the condition of developing human life at the stage of a few-celled embryo is reconsidered, a significant fraction of embryos generated for in vitro fertilization (IVF), heretofore misclassified as nonviable, will be found to be organismically dead. If this is so, the ethical framework currently used for obtaining essential organs for transplantation from deceased adults and children could be extended to cover obtaining stem cells from dead human embryos.

References
1. D.W. Landry and H.A. Zucker, "Embryonic death and the creation of human embryonic stem cells", J. Clin. Invest., vol. 114, pp. 1184-1186, 2004.