Rachel Ridgeway, a mother of six in Washington, welcomed twins conceived in 1992. The twins were stored as embryos in liquid nitrogen for nearly 30 years until adopted by Ridgeway, who is technically only three years older than her newborns.

Even as teeny tots, the twins, Timothy and Lydia, are setting records. They are believed to be the oldest frozen embryos born alive.

“It’s mind-blowing to think about,” said Phillip Ridgeway, the twins’ adopted father. “Pretty much everybody we’ve talked to has trouble wrapping their brain around it.”

Although the biological parents remain anonymous, they originally conceived the twins through in-vitro-fertilization (IVF).

During IVF, many more embryos are formed than necessary. During the process, lab technicians grade the embryos based on the number and quality of cells formed after 3-5 days of fertilization. Extra embryos or embryos considered less optimal are stored for a later date, donated to stem cell research, or discarded altogether.

In the case of the Ridgeway twins, the embryos were donated to the National Embryo Donation Center (NEDC) located in Knoxville, Tennessee. This is a nonprofit that stores embryos for future married couples. The NEDC, founded in 2002, currently stores thousands of donated embryos and estimates that 1 million human embryos are stored nationwide.

Although Rachel and Phillip have four children, they decided to have more.

“We’ve always thought, ‘Let’s have as many kids that God wants to give us,'” said Phillip. “We thought, ‘We’re not done yet if that’s God’s will.'”

Quickly, the Ridgeways decided that embryo adoption was the route for them versus traditional IVF treatment.

The twins were located in the “special consideration” section of the NEDC. The section contains embryos whose families have a known history of genetic disorders. The biological father of the Ridgeway twins died from what is commonly called Lou Gehrig’s disease, or ALS.

“We found out that these kids are rarely looked at because many parents coming into the process are wondering what they could have,” Rachel said. “It didn’t really matter to us if they’re considered perfect or not.”

Prior to the Ridgeways, the longest-frozen embryo record was held by Molly Gibson who was born 24 years after her initial fertilization.

Despite the twins’ record-setting conception and birth, the Ridgeways have decided to wait to tell them of their origins until they are old enough to understand.

“They’ll always know that they are adopted,” Rachel said. “We want to make sure that they know that embryo adoption makes them special.”