California ? A woman gave birth Monday to eight babies, only the second time octuplets have survived more than a few hours, doctors said.

The mother, who was not identified, gave birth to six boys and two girls weighing between 1 pound, 8 ounces and 3 pounds, 4 ounces, doctors at Kaiser Permanante Bellflower Medical Center told The Associated Press.

The hospital had scheduled a Caesarean section for seven babies, but doctors were surprised by the eighth.

Doctors said the babies were born nine weeks premature but are in stable condition. Two newborns were placed on ventilators and a third needs oxygen.

Forty-six hospital staff and four delivery rooms were used for the births. After a baby was born, staff rushed the newborn into another room and waited for the next, the hospital said.

Kaiser spokeswoman Myra Suarez said she could not release any information about the mother, including her condition or whether she used fertility drugs. Such drugs make multiple births more likely.