The world’s tiniest surviving baby, weighing just 8.6 ounces when she was born in December, went home this month as a healthy 5-pound infant.

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The baby, nicknamed Saybie by medical staffers at Sharp Mary Birch Hospital in San Diego, was born there at just over 23 weeks' gestation. Her mother had developed preeclampsia, and doctors decided to perform an emergency cesarean section, according to hospital officials.

The baby’s survival is considered miraculous.

"At birth, she was roughly the same weight as a large apple or a child's juice box," hospital CEO Trisha Khaleghi said.

The hospital went public with the early birth and survival story on Wednesday, explaining that the family wanted to remain anonymous.

The baby was born with a strong heartbeat, neonatologist Dr. Paul Wozniak said, but needed special equipment, including a tiny blood pressure cuff and diapers the size of table napkins.

One of Saybie’s nurses said the baby had a will to live.

“She was a fighter from the get-go,” Kim Norby said.

The baby is now listed as the world’s smallest surviving infant in the Tiniest Baby Registry at the University of Iowa. The previous record was held by a baby girl in Germany who weighed just 8.8 ounces when she was born prematurely in 2015.