David Adam
Thursday July 20, 2006
Guardian Unlimited

A maverick fertility expert has revealed hard evidence of a controversial attempt to produce the world's first cloned human baby.

Panos Zavos, a reproductive scientist, created a storm in 2004 when he called a press conference in London to announce he had cloned a human embryo from the skin cells of an infertile man and transferred it to the uterus of the man's wife. He later said the transfer had failed and the woman did not become pregnant, but many scientists doubted whether he had performed the experiment at all.

Most cloning and fertility experts say such a move to create a clone baby would be unethical and dangerous for mother and child - few female animals implanted with cloned embryos carry them to term or give birth to healthy offspring. The idea could not be taken seriously, they said, until Dr Zavos, who is based at the University of Kentucky and runs a private fertility clinic in Cyprus, published his results and methods in a scientific journal.

Details have now appeared in this month's issue of the Archives of Andrology - effectively placing the experiments on the scientific record, albeit in a little-known specialist journal.

In the paper, Dr Zavos and his colleague Karl Illmensee described how they copied the technique used by UK scientists to make Dolly the sheep - known as somatic cell nuclear transfer (SCNT). They said they took DNA from the man's skin cells and fused it inside three eggs taken from the woman's ovaries, which were given a burst of electricity to encourage them to develop as embryos.

After three days, the paper said, one of the embryos had reached the four-cell stage and "was subsequently transferred into the patient's uterus". Two weeks later, blood tests showed the 35-year-old woman was not pregnant.

The paper said: "This is the first evidence of the creation and transfer of a cloned human embryo for reproductive purposes. Even though no pregnancy was established, human reproduction via SCNT may be possible and applicable in the future." The paper did not say where the pair performed the experiments, which would be illegal in the UK.

Dr Zavos told the Guardian yesterday that he submitted the paper a year ago and had subsequently transferred cloned human embryos to another five women, including a 52-year-old Briton earlier this year. None had resulted in pregnancies.

He confirmed that each was an attempt to produce a cloned baby and said he accepted the risks involved.

"People are right to have concerns, we have those concerns ourselves. Our team is prepared to subject any pregnancy to a very strict scrutiny and make sure they are taken securely and safely to completion."

Richard Gardner, a cloning expert at Oxford University and chairman of the Royal Society's working group on stem cell research, said: "We wanted Zavos to publish his findings and now he has, but a four-cell embryo is very early stage and doesn't tell you anything about whether it would be able to develop further."

According to the paper, the couple involved in the research did not want the scientists to run invasive tests on the embryo to see whether it was healthy because of their religious beliefs. Dr Zavos said the subsequent transferred embryos were more advanced, up to 10-12 cells each.

Professor Gardner supported calls for a worldwide ban on reproductive cloning because he said the technology was currently unproven, but said the technique could possibly be used in future to treat infertility in rare cases where the man produces no sperm.

"It's always difficult to make the decision about when you should be able to transfer animal work into humans."

In a separate paper published in the journal Fertility and Sterility in April, Dr Zavos' group described experiments that created dozens of hybrid embryos made by fusing human DNA inside cow eggs. These embryos were not intended to be transferred to women, but to help improve the cloning process.