Bolivian doctors said Thursday they have successfully removed a 15-kilogram (33-pound) tumor from a woman in her 35th week of pregnancy who has since given birth to a healthy baby girl.

"We took out a tumor of 15 kilograms and there were multiple inside. The lady was a 25-year-old woman who was 35 weeks pregnant and this was her first pregnancy," medical team leader Ariel Tapia told AFP.

The deputy director of Juan XXIII Hospital in La Paz said the operation was performed last week and that the mother gave birth on Tuesday to her daughter, weighing nearly three kilograms (6.6 pounds).

The tumor was located in the stomach of the woman, who was carrying a total extra weight of 18 kilograms (40 pounds).

Three teams of doctors took part in the operation -- , neonatologists and surgeons.

"I have no knowledge of another operation in Bolivia to remove a tumor of this size," Tapia said.

He said the woman, who was not identified, had been an emotional wreck when she first arrived at Juan XXIII Hospital because doctors initially told her she would have to abort her child as her life was in danger due to the tumor.

"It is likely that the woman began to develop the tumor when she was 10 years old. And although it was very large, it did not cause great discomfort."