While little baby Emma Wren Gibson may be only four weeks old, she was actually conceived in 1992, on year after her mother Tina was born.

"I think it makes it all that much more of a miracle," Tina Gibson said.

Emma Wren spent more than 24 years as a frozen embryo at the National Embryo Donation Center in Knoxville.

Emma Wren was born in November 2017 after spending more than 24 years frozen as an embryo.

"We are approaching our 700th birth or child," said Dr. Jeffrey Keenan, the medical director at NEDC.

Keenan said they have transferred nearly 1,500 previously frozen embryos to women hoping to give birth.

"They all have our own story to tell and a lot of times, these families have been through failure after failure, so to be able to give them that hope, it's just an awesome thing and we share that excitement every time," he said.

Like Emma's mother, Dr. Keenan believes there's more to the process than just science.

"We can't control implantation. We can't control embryo development, so are God's hands in this? Yes, I'm convinced of that every time," he said.

The National Embryo Donation Center in Knoxville, Tennessee, has helped nearly 700 babies be born from frozen embryos.

He estimates they have about 500 sets of frozen embryos waiting to be fertilized, but not every one will result in a successful pregnancy.

"The delivery rate per embryo transfer is about 45 percent," he said.

LEARN MORE: National Embryo Donation Center

In Emma's case, there are still two frozen embryos available from her group.

"The couple can return in the future for an attempt at another child and it will be even longer that they are frozen," said Carol Sommerfelt, the embryologist at NEDC.

She said Emma's story proves that the age of an embryo doesn't matter.

"It does open up the eyes of the industry, too, because there are still quite a few people out there that may believe that after five to 10 years those embryos aren't going to be viable any longer," Sommerfelt said.

Sommerfelt answered questions on WBIR's Facebook Live Wednesday night after many viewers asked about the cost, the process and the procedure.

While some of the embryos may never become a child, the doctors are determined to help as many families as they can.

"To be involved and to help build these families is the most rewarding work you can do out there," Sommerfelt said.