It's a rare event, occurring about once in 500,000 births.
Surgeons operated on a 2-month-old Pakistani girl Tuesday to remove two fetuses that had grown inside her while she was still in her mother's womb, a doctor said.
The infant, who was identified only as Nazia, was in critical condition following the two-hour operation at The Children's Hospital at Pakistan Institute of Medical Science in the capital, Islamabad, said Zaheer Abbasi, head of pediatric surgery at the hospital.
Abbasi, the chief doctor who led the operation, said the case was the first he was aware of in Pakistan of fetus-in-fetu, where a fetus has grown inside another in the womb.
"It is extremely rare to have two fetuses being discovered inside another," Abbasi told The Associated Press, adding that he did not know what caused the medical abnormality. "Basically, it's a case of triplets, but two of the siblings grew in the other."
WASN'T THIS THE TROUBLE WITH TRIBBLES? Surgeons Remove Two Fetuses From Infant. It really isn't funny.