Fox News correspondent Catherine Herridge had a difficult second pregnancy, but aggravating her physical problems was a nagging feeling -- call it mother's intuition -- that all was not right with her baby, either.

Her doctor pooh-poohed her concerns, but Ms. Herridge was right.

Within five weeks of giving birth to Peter, he was diagnosed with biliary atresia, a condition of unknown cause in which the common bile duct between the liver and the small intestine is blocked or absent. If undiagnosed, it leads to liver failure.

"He underwent interventional surgery," Ms. Herridge, now 44, said. "It buys some time or saves the liver."

In Peter's case, it didn't save the liver and it didn't buy much time. A little more than five months after Peter was born, she donated 20 percent of her liver for transplantation into her second son.

Now, at the age of 2 years 7 months, Peter is an active, headstrong little boy who was to participate yesterday in the 50-yard diaper dash at the National Kidney Foundation's 2008 U.S. Transplant Games, a four-day, Olympic-style athletic competition designed to showcase the success of transplantation and publicize the need for organ donors.

Ms. Herridge, official mistress of ceremonies for the games, awarded medals to winners of the track and field events at Carnegie Mellon University early in the afternoon, then moved on to Soldiers & Sailors National Military Museum and Memorial to serve as keynote speaker at an event honoring living donors like herself.

She became a living donor after Peter just missed getting a cadaver liver.

At 3 months old, Peter went on the national wait list for a cadaver liver. At Children's Hospital of Pittsburgh, doctors told Ms. Herridge and her husband, J.D. Hayes, that he would need a transplant within three months.

He almost got one. Ms. Herridge was in a federal court in Virginia waiting for a verdict in a case she had covered for five years when she got a call that a liver was available.

She called her bosses and told them to send another reporter to take over the story. But before that could happen, she got another call.

"The liver and small bowel had gone to a sicker child who needed both," she said, adding that it left her with conflicting emotions. "On the one hand you want the sicker child to get it, but you also want your own child to get it."

It was at that point that the doctors talked to Ms. Herridge and Mr. Hayes about living donor transplantation. Ms. Herridge was the obvious choice of the two because she was much smaller than her 6-feet-plus husband.

"A small section works better. If it's a big liver, it has to be cut down and more surgical connections have to be made," she said.

The surgery took place at Children's Hospital on June 6, 2006.

"In my case, they took two entire lobes, 20 percent. It was a minimal amount of cutting. It was a bit big for him, but it worked."

Now people call Ms. Herridge a heroine, a label she rejects.

"I don't feel like much of a hero," she said. "There really was no choice. Either I was going to do this or he would die. There was no way he was going to get a pediatric organ. It's very difficult."

So were the two surgeries. Ms. Herridge's surgery lasted seven hours. Peter's was 10. She took three months off work and, she said, "it took a year to really feel like my old self. It was a big surgery."

One nurse had told her it would feel a "little bit like getting shot in the liver." Another compared it to getting hit by a truck. Both were apt descriptions.

Peter, meanwhile, was very sick for a month after the surgery. Ms. Herridge remembers a nurse coming in and telling her about the Transplant Games and suggesting she come back this year and bring Peter.

"I'm thinking ... that sounds really good, but I just want him to live. ... I want to see him walk across the room," she said. "It seemed like such an impossibility after what he'd been through."