SAN FRANCISCO (CBS SF) — To look at little Elianna as she quietly sleeps in her mother’s arms, you would never know the high-tech life-and-death battle she went through the months before her birth.

During an ultrasound, doctors discovered she had the most severe form of a genetic blood disorder called Thalassemia. Her red blood cells were not working properly. She was not getting the necessary oxygen for her developing body.

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“A lot of (parents of) patients with this disease actually are told that it’s completely fatal,” said Dr. Tippi MacKenzie from the University of California San Francisco.

Most advanced medical centers offer fetal blood transfusions to keep babies with Elianna’s condition alive until birth. Then they do a stem cell transplant in the hopes of correcting the disorder.

But that course of treatment has it’s own problems like finding a donor and the power anti-rejection drugs that blunt the baby’s developing immune system.

“It’s rare to see survivors but we’re hoping that with fetal therapy, more of these fetuses could survive to birth,” Dr. MacKenzie said.

At UCSF, Dr. MacKenzie has spent more than 10 years developing a procedure to do a stem cell transplant at the same time as the necessary blood transfusions inside the womb.

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The procedure uses the mother’s stem cells.

“We made the discovery that the fetus tolerates stem cells that are harvested from the mother the best and actually if you transplant stem cells from any other source, the mother’s immune system comes in to fight these new cells,” Dr. MacKenzie said.

Elianna got a series of five stem cell transplants from her mom starting four months before her birth.

“We’re hoping that those stem cells will survive and give rise to new red blood cells that will treat the baby’s disease,” Dr. MacKenzie said.

Elianna and her family have returned to their home in Hawaii. They will return for checkups, but so far the little girl is recovering well.

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“We’re very excited that the baby was born healthy,” Dr. MacKenzie said. “For us, it’s been very gratifying.”