The father of a 9-month-old baby born with a rare congenital defect called "mermaid's syndrome" said Monday she is doing well ahead of an operation to separate her fused legs.

Ricardo Cerron, 24, also said he dreads the danger she still faces. His daughter, Milagros, was born April 27, 2004 with sirenomelia (search).

On Feb. 8, three bags of silicone were inserted between the baby's ankles, knees and thighs during a three-hour operation. The bags will be filled with saline solution every three days to stretch the skin.

Milagros has been undergoing daily sessions in a hyperbaric chamber (search) to improve blood circulation to her skin and the fat in her legs.

"We have gone through some difficult moments waiting," said Cerron. "The first operation was a little bad but the hyperbaric chamber sessions are going well."

Doctors said the operation will occur in 35 to 40 days but Milagros must first complete 20 days of hyperbaric treatment.

Milagros, which means "miracles," was in the arms of her mother, 19-year-old Sara Arauco, during a visit by an Associated Press Television crew on Monday. The baby is one of only three known cases in which children with the condition are still alive.

While the surgical team is optimistic, the team's head, Dr. Luis Rubio, stressed the complications.

"This is an anatomy totally different from a normal anatomy," he said. "There are arteries that travel from the right leg to the left side, from the right thigh to the left (and) there are a connection of arteries at the level of the knees."