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When Meghann Adams learned that she was pregnant in early 2015, she was ecstatic. Starting a family with her husband, Chris, had not been easy, but she was carrying twins. They were to be named Delly and Aubrey.

The entire family delighted in preparing for their arrival. Adams’ mom, Jamie McNeil, made plans to retire and moved across the country to help care for them.

“It was the best feeling ever,” Adams, 35, told CNN Chief Medical Correspondent Dr. Sanjay Gupta in the family’s home near Atlanta.

Twenty weeks into her pregnancy, Adams had an anatomy scan, a key ultrasound in which the fetuses’ development is measured. The sonographer was upbeat and pointed out all the different parts of the girls. But when the doctor came in, the tone changed.

Although Aubrey appeared to be healthy and growing well, the ultrasound revealed cysts on one of Delly’s kidneys.

The Adamses were ushered in to meet with a genetic counselor. Stats and medical terms were bandied around. The diagnosis: multicystic dysplastic kidney, which is believed to affect one in 3,500 births. It occurs when the kidney is malformed and full of cysts and, as a result, can’t function. In most cases, children who have just one kidney live normal lives; the remaining kidney will take over and essentially do double duty. But in some cases, a kidney transplant might be necessary.

McNeil, the twins’ grandmother, wanted to be a donor, but there was no way to know if or when Delly might need a kidney.

“It was just really overwhelming and devastating,” Adams said. “We were on pins and needles for a while, just really unsure.”

The long wait for a healthy kidney

Delly and Aubrey were born six weeks early, in December 2015. Because of her diagnosis, Delly was immediately taken into the neonatal intensive care unit for monitoring. “I didn’t even get to hold her the first day when she was born,” Adam said.

Those initial days were a blur. Adams was recovering from a C-section and trying to get the hang of breastfeeding.

Delly was prodded and poked, her kidney monitored to make sure it was keeping up. At just 6 days old, she began to experience renal failure.

“I just didn’t know how to react or what to do,” Adams said, “and my mind was going in a million different directions.”

Doctors began talking about dialysis and transplants, but Delly was simply too small and too young for surgery.

Delly Adams in the NICU at 6 days old.

Slowly, Delly’s kidney began to pick up. She was in the NICU for her first month, and every day, her blood was tested.

At 3 months, Delly’s blood levels were stable. But her healthy kidney hadn’t grown as much as doctors had hoped by the end of her first year.

Her nephrologist began talking about the potential need for a transplant – not immediately, but maybe not so far into Delly’s future.

‘A gift certificate for an organ’

For those in need of a kidney transplant, the wait is long. Of the nearly 100,000 people waiting for a kidney last year, only about 20% were able to find a match, according to the United Network of Organ Sharing. Finding that match took an average of three to five years.

Delly’s next big test will be puberty, when they’ll see whether her kidney will be able to keep up with her growing body. Knowing that Delly could one day find her self on the waiting list for a kidney, Adams and her mother, McNeil, began researching options to prepare.

McNeil didn’t hesitate: She dreamed of being a donor. But she’s in her 50s and would probably be too old to donate by the time Delly actually needed a kidney.

And that’s how they came across an innovative new program, the National Kidney Registry’s Voucher Program.

Essentially, it’s “a gift certificate for an organ,” Adams said.

Donors ‘waiting for their recipient’

The program began at the University of California, Los Angeles four years ago, when then-64-year-old Howard Broadman approached the UCLA Kidney Exchange Program led by transplant surgeon Dr. Jeffrey Veale with the idea of donating his kidney to a stranger now in exchange for a voucher that would potentially provide a kidney for his grandson in the future.

Like Delly, Broadman’s grandson, Quinn, then 4, was born with chronic kidney disease. And like McNeil, Broadman was a chronological mismatch with his grandchild – probably too old to donate by the time the boy needed one.

Veale mulled the idea over. Living donor transplants can cut wait times by years, and research has shown that that living donor kidneys tend to outlast those from deceased donors.

Veale didn’t want to lose out on the opportunity of a potential donor. After all, altruistic donors – people willing to donate to complete strangers – were key in jump-starting transplant chains that could benefit multiple patients.

Transplant chains are able to take pairs of mismatched living donors and recipients and scramble them around to create chains of matching pairs. The longest chain has resulted in over 100 kidney transplants or swaps. But these chains require all donors be ready to give and recipients ready to receive at the same time.

Veale decided to add Broadman to the donor pool to start a chain. In return, Quinn received a voucher that would place him at the end of a future chain once he needed a kidney.

“The voucher capitalizes on donor-recipient pairs who are chronologically incompatible,” Veale said. “These are patients who want to donate their kidney now but are waiting for their loved one, who doesn’t quite need a kidney yet.”

Adding chronological mismatches into the donor pool only improves everyone’s chances at finding a match, explained Dr. Nicole Turgeon, a transplant surgeon at Emory University and McNeil’s doctor.

“It really would be in our best interest as a community to come together and have as many pairs as possible in a system to allow for the most transplants possible,” Turgeon said.

The vouchers are all coordinated through the National Kidney Registry’s living donor databases. At least 36 vouchers have been distributed, and two have been redeemed. A voucher can be activated only by the person it is initially designated for, and it expires when the voucher holder dies.

The first three “voucher donations” triggered 25 transplants.

For Delly and her grandmother, the voucher program was the answer.

‘A dream come true’

McNeil had long hoped to find a way to be an organ donor. When the retired nurse learned of a colleague who had advanced breast cancer and needed a bone marrow transplant, McNeil immediately signed up to be a bone marrow donor.

She’s never been called to donate, though, and always wondered about other ways to help.

“My soul needs a connection with humanity,” she said.

There were risks; kidney donation is still surgery. And while rare, long-term impacts can include pain, nerve damage, hernia or intestinal obstruction.

None of that dissuaded McNeil. “I’m a nurse, so I know what all those things are. But because I’m so driven again to do it, that I just know it’s the right thing to do,” she said before the surgery. “My soul is at peace with whatever might happen.”

Jamie McNeil holds her granddaughter, Delly Adams.

In September, McNeil donated her kidney to a stranger. The donation inspired by her granddaughter triggered a chain of three other transplants. All the donor and recipient surgeries occurred on the same day, with organs criss-crossing the country.

“It’s like a dream come true to me,” McNeil said.

For McNeil, her donation is not just a gift to Delly but part of a larger mission to better what’s around her.

“I wish to see more love, and so I’m going to be that love,” she told Gupta. “If I could inspire just three more people to donate kidneys and those three people could inspire three more people. And those three could inspire three more. If you just did that 11 times over, we would completely wipe out … the kidney waiting list. That’s doable to me.”

McNeil said that donating a kidney would be one of the most significant days of her life.

“When I’m on my deathbed,” she said, “the thing I’m going to say that I’m the proudest of will probably be that day.”

‘We’re more similar than different’

McNeil returned home just a day after her surgery, and though she was sore, she was in the best of spirits.

Her kidney had been sent to a recipient at the University of Rochester Medical Center in New York. A donor there sent a kidney to a recipient at the Mayo Clinic in Minnesota, and a donor there sent one to a recipient at the Nicoletti Kidney Transplant Center at Jefferson Health in Pennsylvania. The chain ended with a final donor from Jefferson sending a kidney to a recipient at New York Presbyterian.

The news that excited McNeil most that day was to hear that her kidney had been received and was already producing urine for its new recipient.

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“These chains exemplify how we’re more similar than different, often matching patients of different ethnicities, religions, genders, sexuality and political affiliation. There are other benefits too, as the voucher donor helps a stranger receive a kidney today and extends the voucher donor’s legacy by helping a loved one receive a kidney in the future,” Veale said. “We need a little more kindness in the world, and this is what these voucher donations do.”

Delly knows very little of the unique gift that her grandmother gave. All she knows is that her grandmother is a one-kidney person, like her.

And to Delly, that doesn’t mean much. At 2½, she can still run around and play with her sister in their toy kitchen, read books and giggle with her grandma.