Chinese scientists have come close to creating the world's first baby with three parents, report agencies.
They created embryos using eggs from two women and sperm from a man. Details of the experiment were presented at the American Society for Reproductive Medicine annual conference in San Antonio, Texas.
Experts at the Sun Yat-Sen University of Medical Science in Guangzhou treated a 34-year-old woman who had undergone two IVF cycles, which had failed because of problems with her eggs.
A donor egg was taken and all genetic material removed before the nucleus of the woman's egg was put into the empty one.
The researchers succeeded in transferring five of the three-parent embryos into the woman and she became pregnant with triplets. A month into the pregnancy, doctors aborted one foetus to give the remaining two a better chance.
But at months four and five, the remaining two were delivered prematurely and died, said The Independent.
The researchers claim the deaths were related not to the nuclear transfer process but to poor care of the woman during her pregnancy.
Critics, however, have attacked the experiment and accused the scientists of taking a major step towards human cloning. The technology behind the Chinese experiment was developed in the United States.
But US scientists had stopped their work after the Food and Drug Administration cracked down on fertility experiments. China has now announced that it too will outlaw embryo research, The Independent said.