Infant Emma Wren Gibson, born November 25, 2017 in Knoxwville, Tennessee, is seen in this handout photograph obtained December 20, 2017. (Tina & Benjamin Gibson/AFP/File)
An American woman has given birth to a healthy baby girl from an embryo that was frozen a quarter century ago, in what hospital officials say may be a world record.
The baby, named Emma Wren Gibson, was born November 25, according to the National Embryo Donation Center (NEDC) in Knoxville, Tennessee, which revealed the birth announcement this week.
The embryo was conceived by another couple and frozen on October 14, 1992.
Tina Gibson, the woman who just gave birth to Emma Wren, was born in 1991, NEDC marketing director Mark Mellinger told AFP on Wednesday.
By some measures, that would make the embryo that became Emma Wren only about a year younger than her mother.
"We could have been best friends," said Gibson, now 26, in an interview with local television WBIR.
Gibson said she wasn't told by doctors until she was pregnant that the embryo had been frozen more than 24 years earlier.
"I just stared at them, I was like, what? Are you kidding?"
Mellinger said Gibson and her husband selected the embryo based on a profile of genetic characteristics, but was not told how long the embryo had been frozen.
Gibson was implanted with three embryos, and only one survived, he added. There remain two more cryopreserved embryos from the same biological parents.
The case marks the "longest-frozen embryo to successfully come to birth," said the NEDC, citing the research staff at the University of Tennessee Preston Medical Library as a source.
However, some experts expressed caution about proclaiming such a record.
US companies are not required to report the age of the embryos, just the outcome of the pregnancies, Zaher Merhi, director of IVF research and development at New Hope Fertility Center in New York, told CNN.
"Nobody has these records," he said.
The previous record-holder was believed to be a baby boy frozen for 20 years, born to a New York woman in 2011.
The embryo was stored by the NEDC, a Christian organization that describes itself as "the world's leading comprehensive embryo adoption program," with 686 babies born to date.
Its mission is to "protect the lives and dignity of frozen embryos that would not be used by their genetic parents and to help other couples build the families they have longed for via donated embryos."
Gibson and her husband were unable to conceive a child on their own, and are thrilled with their new baby.
"Emma is such a sweet miracle," said father Benjamin Gibson in a statement.
"I think she looks pretty perfect to have been frozen all those years ago."