"I can hide a lot of emotion under my beard," Dad says.

Going room to room, my father -- in his velvet red suit, white wig and beard, white gloves, black boots, and gold glasses -- surveys the hallways. There are rooms with pink signs, meaning Santa cannot enter because the child's condition doesn't allow for it. In between rooms, Dad reminds me of last year's run-in with several players from the Houston Texans, who had also come to visit the children. Santa, a Texans season-ticket holder, pointed his index finger in the direction of quarterback Matt Schaub and others, and, in so many words, ordered them to stop slacking off. (After going 6-10 last year, the Texans are making the franchise's first playoff appearance this season. Coincidence?)

Meeting with a hospital official, I'm invited to speak to a patient and her family.

"You have to meet Macie McCartney," she tells me. "She was the baby born twice."

"Wait, say that again?" I ask.

"She was born twice."

Macie McCartney doesn't know it, but four years ago, doctors didn't expect her to be here today. On February 15, 2008, just 23 weeks into her pregnancy, Keri McCartney and her husband, Chad, went in for an ultrasound to find out the gender of their fifth child. Keri was hoping for a girl. During the examination, the sonogram tech looked around the room, remaining quiet. Finally, she spoke.

"She said the baby had a very large mass growing on her tailbone," Keri McCartney remembers. "She said, 'It's probably as big as the baby.' She told me right away it was sacrococcygeal teratoma."

Keri and Chad learned that one in every 40,000 babies develops this non-cancerous yet potentially fatal external tumor. The tumor, which turned out to be the size of a grapefruit, was growing so rapidly on Macie McCartney's tailbone that it was stealing blood her body needed to develop properly inside her mother's womb. Keri's OB gave Macie a one-in-10 chance of survival.

And the options were emotionally complicated and medically risky: Either Macie would have to be delivered at around 25 weeks, with the strong possibility that she wouldn't be able to live outside the womb, or doctors would have to perform fetal surgery to take Macie out at 25 weeks, remove the tumor, and place her back into the womb to recover.

Less than two weeks after finding out about the tumor, the McCartneys decided to go ahead with open fetal surgery, a procedure that had been successfully completed fewer than 20 times worldwide. It would be the first time the operation would be conducted at Texas Children's Hospital. But with Macie's heart getting weaker by the day and excess fluid building up around it, there wasn't much time to deliberate.

On February 28, 2008, doctors performed a C-section, working with 80 percent of Macie's body outside the womb while her head and upper body remained inside and blood continued to flow from her placenta. Keri McCartney remembers nothing of the procedure; she told me she was given seven times the normal dose of anesthesia so that her uterus would stay completely at ease during the surgery.