Rome ? A healthy 3 1/2-month-old girl who came into the world weighing just 9.97 ounces spent her first full day home from the hospital Saturday, and her doctors said they believed she was the tiniest human being to live so long.

Doctors at Careggi hospital in Florence sent the “miracle” baby home Friday weighing 4.4 pounds, saying she has a nearly 100 percent chance of enjoying a normal life.

“She really had the will to live, she was strong and lively,” Margarita Psaraki, the pediatrician on the baby’s medical team, said Saturday. “She was immediately lively, active. This helped us to help her.”

Doctors said that at the parents’ wishes, they were identifying neither the baby nor the parents, who live near Florence. The medical team nicknamed the girl “Pearl.”

The baby was delivered by Caesarean section in early February during the 27th week of pregnancy. At that stage of prematurity, some babies do survive, but they have weighed much more at birth.

“We were completely taken aback. The weight is usually double that” at the 27th week, said Psaraki, interviewed by phone at her home after finishing her shift at the hospital.

Psaraki said the baby’s survival “is an absolute record.”

The previous record was set in the 1990s by a baby in Japan who weighed 10.5 ounces at birth, doctors said Friday at a news conference in Florence. A low birth weight is considered to be 2.5 pounds and under.

Early in the pregnancy, “Pearl’s” mother was diagnosed as having a problem with arteries, and at one point was at risk of needing a leg amputated, the doctors said. That persuaded them to deliver the baby early but at a stage when survival is possible.

Many of the premature babies who do survive birth at the 27th week or even later go on to have serious physical or mental handicaps, and there is intense debate in the world of medicine and ethics over how much extraordinary intervention should be used in such cases.

“I was afraid of holding her,” Psaraki said. At birth, “she was 10 inches long. But that’s when she was stretched out. Normally babies curl up and then she would fit right into your hand.”

After delivery, the baby’s weight dropped to 8.92 ounces, but she rebounded.