The condition, known as sirenomelia or mermaid's syndrome, is almost always fatal. The baby has survived for two weeks at Children's Hospital in Changsha thanks to dialysis, Xinhua, the official government news agency, said.

The little boy has a host of congenital problems, including a blocked intestine, missing kidneys and urinary tract, a malfunctioning heart and underdeveloped genitals. Zhu Yimin, the hospital president, said the baby will need extensive surgery before doctors can even think about separating his legs.

"The operations will be complicated and risky, but we'll try our best," he said.

Only two children born with the syndrome are known to have lived beyond a few weeks -- a 17-year-old girl in the United States and a 2-year-old Peruvian girl. Both have had their legs surgically separated.

The baby was left in front of the hospital Nov. 12 with a note pinned to his clothing saying he had been born three days earlier.