WASHINGTON (WASHINGTON POST) - Ms Alysha Kellner was 23 weeks' pregnant when she learned last year that her baby had a rare, fast-growing tumour on her heart that might require surgery while still inside the womb.

It was earth-shattering news that didn't stop there. Foetal surgery to remove this type of tumour had been done successfully just three times in the world and had never even been attempted by Ms Kellner's doctors at Children's Minnesota.

Once she got past the initial shock, Ms Kellner swore there was no way she would trust the surgeons to take their first shot at a high-risk procedure on her baby.

Then she grasped for hope: Maybe she would make it to 28 weeks, a far cry from a full-term, 40-week pregnancy but far enough along for the baby to be delivered and then operated on after birth.

That hope didn't last long.

The first sign that something might be wrong had come at 21 weeks, when a routine ultrasound flagged a small amount of fluid around the baby's heart. The Kellners' doctor suggested she follow up with a specialist.

Alysha, a high school Spanish teacher, and her husband, Ben, a mechanical designer, made the appointment and decided not to worry about it.

Instead, they threw a party to celebrate the pregnancy at their house in Shoreview, Minnesota, north of St Paul.

The party featured a cake that held the secret of the baby's gender beneath its yellow and white icing. Alysha and Ben cut into it together, and everyone could see that the inside was pink. It was a girl.

Then came their visit with the specialist at the Midwest Foetal Care Centre at Children's Hospital and Clinics of Minnesota, where they were blindsided by the news: Their baby had a foetal teratoma, a rare kind of tumour. And hers was an even rarer type that is called a pericardial teratoma because it is found on the heart.

They also learned that the tumor had caused a dangerous amount of fluid to accumulate around the baby's heart and that the fluid would need to be drained with a needle. Then they discussed what might happen next.

Ideally, the tumour would avoid causing too many more problems until the pregnancy had passed 28 weeks, when doctors could operate on the baby while she was still attached to the placenta and then deliver her using an ex utero intrapartum treatment, or EXIT procedure.

The Minnesota doctors had related experience: They had done EXIT procedures for other conditions, and they had operated on tumours in newborn babies before.

But if the tumour grew too quickly and put too much stress on the baby before 28 weeks, Alysha and Ben would have to decide whether to try to save the baby with a more advanced kind of foetal surgery.

Surgeons would slice through Alysha's uterus and the baby's chest and remove most of the tumour. But instead of delivering the baby as with an EXIT procedure, they would sew mother and baby back up for the remainder of the pregnancy.

Children's Minnesota had started performing open foetal surgeries like these just a year earlier, after the arrival of pediatric surgeon Joseph Lilligard, and the hospital didn't have experience with foetal teratomas.

The era of open foetal surgery was still fairly new. It began in 1981, when doctors at the University of California at San Francisco (UCSF) successfully operated on a fetus with a blocked urinary tract.

In the early days of the technique, doctors cut through a mother's uterus only when a foetus' problems were bound to be lethal, Dr Lilligard says. As a result, there were a lot of early failures.

Eventually, the procedure became more common, especially for a form of spina bifida in which a baby's spinal cord and spinal canal don't close during development, leading to nerve damage and other problems.

Between 1997 and 2003, doctors performed more than 200 open surgeries in the United States on foetuses with spina bifida. And the procedure appeared to improve outcomes even as it remained controversial: Some people thought it put the mother and baby at too much risk.

A turning point came in 2011, when researchers at Children's Hospital of Philadelphia (CHOP), UCSF and other institutions reported that, compared with babies who underwent surgery for severe spina bifida after birth, those who received open foetal surgery before 26 weeks of gestation were more likely to survive and less likely to need shunts in their spinal cords by their first birthdays.

At 30 months old, the babies who were operated on as foetuses were more likely to walk independently, among other measures.

The study was a game-changer, says Dr Brad Feltis, a pediatric surgeon at Children's Minnesota who has long specialised in minimally invasive foetal surgeries, which are not an option for fetal teratomas.

"It opened up a new realm of possibilities," he says.

One of those possibilities was operating on a foetal teratoma, a far riskier surgery than one for spina bifida.

In 2013, just four years before Ms Alysha Kellner got her diagnosis, doctors at CHOP, led by paediatric and foetal surgeon Alan Flake, performed the first successful open foetal surgery on a pericardial teratoma.

The CHOP team followed with two more - the only times the procedure had ever been performed successfully anywhere in the world.

The condition is so rare, Dr Lilligard adds, that Children's Minnesota has diagnosed just three or four foetal teratomas in the past 10 years.

The most recent one had been in 2014, before the hospital started its open foetal surgery program, and that baby died without undergoing surgery.

The Minnesota doctors explained the surgery to Alysha and Ben, and they did not sugarcoat the risks.

The baby might not survive the operation or might have to be delivered during the procedure - more than two months early.

And even if the baby did make it, Alysha's uterus could rupture later in pregnancy, which would be fatal for the baby and an emergency for the mother.

At first, Alysha was determined to go to Philadelphia if the surgery became necessary. But when she met the Minnesota doctors, she felt comfortable with them. Being close to home also sounded appealing. She and Ben decided that, if the surgery became necessary, they would stay.

Preparations began immediately, just in case. Dr Lillegard, who has two children and a history of mountaineering and rock-climbing, gathered a team of more than a dozen specialists, included a foetal cardiologist, paediatric surgeons, anaesthesiologists, even an ethicist.

Three times a week, Alysha was given a foetal echocardiogram to monitor the baby's heart. Just as often, doctors met to discuss the case. Twice, they ran through simulations of anything that might go wrong during the surgery.

Dr Lillegard also sought advice from colleagues, including Dr Flake, who had been one of his mentors at CHOP.

When Dr Lillegard called him, Dr Flake sensed that the Minnesota doctors faced the added pressure of needing to prove themselves as a new programme attempting a complex surgery.

"It's a very invasive and delicate procedure," says Dr Flake. "You're taking a tumour off of the heart. Babies are usually compromised by that tumour and are in some kind of heart failure to begin with. Any time you compromise cardiac function any further, you have the potential for deterioration and death."

By the time Alysha was 26 weeks pregnant at the end of July, the fluid had returned around her baby's heart despite having been drained a few weeks earlier. And the tumour had quadrupled in size. Dr Lillegard called her and Ben in for a talk.

In a conference room on a Saturday morning, he showed them an MRI scan of the baby on a large TV screen. They could see where the tumour had shoved her heart down near her stomach and pushed it sideways. She would not survive without surgery.

Alysha didn't have to go through with it. The doctors made that clear. But she never considered backing out.

Before the procedure, she and Ben picked out a name for the baby: Kora Amada. In Spanish, "Amada" means "loved".

"Kora" reminded them of "corazon," the Spanish word for heart.

Two days later, on July 31, Dr Lillegard talked with Alysha as she was being prepped for surgery.

"I don't think I'll ever forget this as long as I live," she says. "He's at the foot of my bed, and he's, like, 'OK, we're going to put you under. And there's a 50-50 shot: The baby is either going to survive or not.'"

The surgery began at 8am, with two incisions on Alysha's abdomen. Music is common in an operating room during routine procedures. But the only sounds that day were words of communication among the 20 or so doctors and nurses present.

Guided by ultrasound, an incision in Alysha's uterus exposed the baby's chest and arms, which the surgeons splayed out, like a gymnast at the end of a routine - chest up, back arched. The foetus had her own anaesthesiology team and tiny IV. She weighed less than two pounds. Each arm was smaller than a surgeon's index finger.

When the doctors cut open her chest, Dr Lillegard says, the tumour bulged out. Roughly the size of an orange, it was four times bigger than her heart.

Lillegard and pediatric cardiovascular surgeon Francis Moga used tweezer-like electrocautery tools to remove the tumour, bit by bit.

They wanted to work quickly while also allowing time to observe and respond to distress in the baby.

When her heart occasionally slowed down, they used medications, gave blood or repositioned the tumour to speed it up.

In the recovery room, Ben waited, playing cards, praying and talking with a small group of family members, including his parents. If a decision needed to be made during the procedure, Ben knew it would be up to him to make the call.

Around 10.30am, Dr Lillegard appeared and told the family that the surgery had been a success. The surgeons had removed more than 90 per cent of the tumour and would get the rest after the birth.

Ben cried. So did Alysha when she woke up and heard the news.

After sewing up the incisions, the doctors celebrated, too.

"I'll be honest, I've never had a hug in the operating room before," Dr Lilligard says. "I think I got three that day."

Kora was born on Sept 29 by Caesarean section at 35 weeks. She weighed 2.83kg. Her eyes were blue, like her dad's.

Dr Lillegard was assisting in the delivery room, and Alysha could tell he was in a good mood.

She remembers hearing him sing It's a Wonderful Life.

As soon as Kora was born, doctors covered the incision in her chest and whisked her to the neonatal intensive care unit.

A week later, they removed the rest of the tumour.

Still in the hospital on Halloween, Kora wore a Wonder Woman costume. She went home in November, wearing a onesie that said "History Maker".

Now more than 7 months old, Kora giggles, babbles, sits and rolls over. Her first solid foods were avocado and oatmeal. Now she likes sweet potatoes and butternut squash.

Her last MRI showed no signs of the tumour. And as her tumor markers continue to drop, Alysha and Ben have become focused on more typical baby issues, such as parental sleep deprivation. Until recently, Kora was waking up every couple of hours at night.

All that remains of Kora's ordeal is a C-shaped scar on her chest and two small scars lower down on her ribs. As soon as she can understand, Alysha and Ben plan to tell her how she got them.