Where Will They Get the Eggs?

Date: 03/12/2002

Cloning advocates argue that they must be allowed to legally clone human embryos in order to overcome the tissue rejection problem [that might arise from therapies derived from unmatched embryonic stem cells]. There are two absolutely essential ingredients to successful nuclear transfer cloning. One is a somatic cell from the clone donor. The other is the egg. We can only create as many patient clones for therapeutic use as there are eggs available.

Let’s review the math. More than 100 million people in the United States suffer from medical conditions for which embryonic stem cell therapies are being promoted as promising – Parkinson’s disease, stroke, multiple sclerosis, spinal cord injuries, juvenile diabetes, and more. If 20 percent of cloning attempts succeed in reaching the blastocyst stage of development – the success rate in animal cloning – and stem cells are derived from 10 percent of these clone embryos — a rate consistent with success rates in deriving embryonic stem cell lines from non-cloned embryos — how many eggs will we need?

Dr. David Prentice, a stem cell research expert at Indiana State University, has estimated based on the assumptions above that it would take 800 million eggs just to treat just 16 percent of the Americans who suffer from conditions for which therapies involving cloned embryonic stem cells have been promised. If ten eggs are harvested per woman, then 80 million women of childbearing age would have to submit to the risks of drugs that induce hyper-ovulation and a surgical extraction procedure to provide the eggs that would be needed to develop therapies for just a fraction of those who are suffering from these conditions.

Does anyone really think that 80 million American women are going to submit to these risks in order to provide eggs for use in cloning? Or do cloning advocates envision paying poor women in the developing world to provide their eggs to create therapies for American patients?

The “egg dearth” is a mathematic certainty. It is one reason why researchers say that therapeutic cloning will not be a generally available medical treatment. For example, a year ago biotech researchers Jon S. Odorico, Dan S. Kaufman, and James A. Thompson admitted the following in the research journal Stem Cells:

The poor availability of human oocytes (eggs), the low efficiency of the nuclear cell procedure, and the long population-doubling time of human ES cells make it difficult to envision this [therapeutic cloning to obtain stem cells] becoming a routine clinical procedure even if ethical considerations were not a significant point of contention.

To pour money into human cloning embryonic stem cell research is to risk drilling one dry hole after another. The moral policy thus also turns out to be the pragmatic one. The United States Senate should vote to ban all human cloning now.

(Adapted and excerpted from “The False Promise of Therapeutic Cloning” by Wesley J. Smith, The Weekly Standard, March 11, 2002.)