KNOXVILLE, Tennessee - Tina and Ben Gibson are the parents of two healthy little girls, Molly and Emma, who came into the Gibson's life with the help of Knoxville, Tennessee's National Embryo Donation Center (NEDC).

Emma, who was born in November 2017 and her younger sister, Molly, who was born in October 2020 are believed to have broken records with their births.

Both girls, while still in an embryonic state, were cryogenically preserved on Oct. 14, 1992. Decades later, when Tina Gibson gave birth to Molly and Emma, each of their births made history as what are believed to be the world's longest-frozen embryos to have resulted in a birth.

Ironically, 28-year-old Tina Gibson was only a toddler when her daughter's embryos were frozen.

Dr. John Gordon, an in vitro fertilization (IVF) expert, spoke to Knoxville ABC affiliate news station, WATE, about how the technology works.

“The ability to freeze these embryos in liquid nitrogen at negative 170 degrees, will keep them in the state of animation,” Dr. Gordon explained. “When you think about embryos being frozen, they are a group of cells that have the potential to go on and become a baby.”

According to the BBC, families like the Gibsons are able to adopt one of the unused embryos and give birth to a child that is not genetically related to them. The NEDC says there are an estimated one million frozen human embryos stored in the US right now.

Mark Mellinger, the NEDC's marketing and development director, said that experience with infertility is common among families who seek embryo donations.

"I'd say probably 95% have encountered some sort of infertility", he said. "We feel honored and privileged to do this work", and help these couples grow their families.

The Gibsons admit that IVF wasn't an option they immediately considered, simply because they didn't know much about it.  

"If you would have asked me five years ago if I would have not just one girl, but two, I would have said you were crazy," Tina said.

The couple struggled with infertility for nearly five years before Tina's parents saw a story about embryo adoption on a local news station.

"That's the only reason that we share our story. If my parents hadn't seen this on the news then we wouldn't be here," Tina said. "I feel like it should come full-circle."

Molly and Emma, are genetic siblings; both embryos were donated and frozen together in 1992.

Little Molly's embryo, frozen from October 1992 until February 2020, was 27 years old when the Gibsons adopted it.

She is believed to have set a new record for the longest-frozen embryo to have resulted in a birth, breaking a record set by her older sister, Emma.

According to the NEDC, the shelf-life for frozen embryos is infinite. The time-frame is limited, however, by the age of the technology - the first baby born from an embryo frozen after IVF was born in Australia in 1984.

"It's entirely possible that there will someday be a 30-year-old embryo that comes to birth," Mellinger said.

In any case, the Gibsons are over the moon to have two little girls of their own.

“I am so glad I have these sweet little blessings,” Tina told WATE reporters, “it was worth the wait.”

Click here for more on NEDC.