Help for infertile women, or cloning?

Scientists combine the DNA of a women's egg with the cytoplasm of a donated egg in a procedure not allowed in the United States.

Scientists in China say they've achieved a human pregnancy through a new technique that might one day help infertile women.

The work, which experts said couldn't be done in the United States because of regulatory concerns, did not create live babies.

One ethicist called the experiment "proof of principle" for human cloning, but other experts disagreed, saying the work is not aimed at producing genetic copies of people.

Results are to be reported today in San Antonio, Texas, at the annual meeting of the American Society for Reproductive Medicine. The research was done by scientists at the Sun Yat-Sen University of Medical Science in Guangzhou, China.

They were advised by Drs. John Zhang and Jamie Grifo of New York University Medical Center, whose earlier work had laid the foundation for the new research.

The 30-year-old Chinese woman involved in the experiment had an unusual fertility problem in which embryos stopped developing when they contained only two cells.

Eggs, like other cells, basically consist of a nucleus, which holds most of their DNA, and a surrounding material called the cytoplasm. For the experiment, the researchers removed the nucleus DNA from fertilized eggs and transferred it to the cytoplasm of donor eggs. The idea was to surround the transferred DNA with a new cytoplasm, in hopes that such reconstituted eggs would fare better than the woman's previous attempts at pregnancy.

They did develop much further. The researchers say they achieved pregnancy with triplets. One embryo was terminated at the request of the woman to reduce the medical risk of the pregnancy, Grifo said. The other two died at 24 and 29 weeks from complications that did not appear connected to the procedure.

Dr. Joe Massey, a fertility specialist at Reproductive Biology Associates in Atlanta, said a big question about the experimental procedure is how safe it is. If it does prove safe, he said, it would be a big advance for women with the unusual problem in which their embryos stop developing early.

It's possible such a procedure could help older women who can't use their own eggs, he said.

Jeffrey Kahn, director of the Center for Bioethics at the University of Minnesota, said the procedure raises concern because it is "akin to cloning technology . . . I think this is proof of principle for cloning."

Massey and Sable said the experiment was not cloning. Massey stressed it wasn't aimed at copying a person.

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